The potency of mitochondria enlargement for mitochondria-mediated terpenoid production in yeast

Terpenoids are widely used in the food, beverage, cosmetics, and pharmaceutical industries. Microorganisms have been extensively studied for terpenoid production. In yeast, the introduction of the mevalonate (MVA) pathway in organelles in addition to the augmentation of its own MVA pathway have been challenging. Introduction of the MVA pathway into mitochondria is considered a promising approach for terpenoid production because acetyl-CoA, the starting molecule of the MVA pathway, is abundant in mitochondria. However, mitochondria comprise only a small percentage of the entire cell. Therefore, we hypothesized that increasing the total mitochondrial volume per cell would increase terpenoid production. First, we ascertained that the amounts of isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP), the final molecules of the MVA pathway, were 15-fold higher of the strain expressing the MVA pathway in mitochondria than in the wild-type yeast strain. Second, we found that different deletion mutants induced different mitochondrial volumes by measuring the mitochondrial volume in various deletion mutants affecting mitochondrial morphology; for example,Δmdm32 increased mitochondrial volume, and Δfzo1 decreased it. Finally, the effects of mitochondrial volume on amounts of IPP/DMAPP and terpenoids (squalene or β-carotene) were investigated using mutants harboring large or small mitochondria expressing the MVA pathway in mitochondria. Amounts of IPP/DMAPP and terpenoids (squalene or β-carotene) increased when the mitochondrial volume expanded. Introducing the MVA pathway into mitochondria for terpenoid production in yeast may become more attractive by enlarging the mitochondrial volume. KEY POINTS: • IPP/DMAPP content increased in the strain expressing the MVA pathway in mitochondria • IPP/DMAPP and terpenoid contents are positively correlated with mitochondrial volume • Enlarging the mitochondria may improve mitochondria-mediated terpenoid production.

Production and purification of fucoxanthins and β-carotenes from Halopteris scoparia and their effects on digestive enzymes and harmful bacteria

ABSTRACTAlgae constitute a significant part of marine biodiversity. They represent a renewable source of bioactive metabolites from drug development and therapeutic fields. Fucoxanthin and β-carotene from the brown macroalgae Halopteris scoparia, were extracted using conventional organic solvent extraction, then purified, to homogeneity, based on various chromatographic principles. Their effects on digestive enzymes and harmful bacteria were investigated. The capacities of both purified pigments to inhibit α-amylase and trypsin enzymes were evaluated. Purified fucoxanthin and β-carotene exhibited interesting α-amylase inhibition activities, with IC50 of 300 and 500 µg/mL, respectively. Moreover, trypsin inhibition activities were detected using purified these two pigments. The antibacterial potential of the purified pigments was evaluated. β-carotene showed to be a great antibacterial natural compound against gram-positive and gram-negative bacteria such as Listeria monocytogenes, Staphylococcus aureus and Salmonella enterica with Minimal Inhibitory Concentration (MIC) of about 0.225, 0.1125, 0.225 µg/mL, respectively. Those findings are in favor of the exploitation of H. scoparia pigments in therapeutic fields as an antidiabetic source directly by the inhibition of α-amylase and trypsin as well as antibacterial agents against gastrointestinal infections.

Carotenoids production by Rhodosporidium paludigenum yeasts: Characterization of chemical composition, antioxidant and antimicrobial properties

The high market potential imposed by natural carotenoids has turned the scientific interest in search for new strains, capable of synthesizing a wide spectrum of these pigments. In this study, Rhodosporidium paludigenum NCYC 2663 and 2664 were investigated for carotenoids production and lipid accumulation utilizing different carbon sources (glucose, fructose, sucrose, mixture of glucose: galactose). Strain R. paludigenum 2663 produced the highest total carotenoids titer (2.21 mg/L) when cultivated on sucrose, together with 4 g/L lipids (30% w/w content) and 7 g/L exopolysaccharides. In the case of R. paludigenum 2664, glucose favored the production of 2.93 mg/L total carotenoids and 1.57 g/L lipids (31.8% w/w content). Analysis of the chemical profile during fermentation revealed that β-carotene was the prominent carotenoid. Strain 2663 co-produced γ-carotene, torulene and torularhodin in lower amounts, whereas 2664 synthesized almost exclusively β-carotene. The produced lipids from strain 2663 were rich in oleic acid, while the presence of linoleic acid was also detected in the lipoic fraction from strain 2664. The obtained carotenoid extracts exhibited antioxidant (IC50 0.14 mg/mL) and high antimicrobial activity, against common bacterial and fungal pathogenic strains. The results of this study are promising for the utilization of biotechnologically produced carotenoids in food applications.

Vitamins C, E, and β-Carotene and Risk of Type 2 Diabetes: A Systematic Review and Meta-Analysis

A systematic review and meta-analysis was conducted to assess the relationship between the common dietary antioxidants vitamin C, vitamin E, and β-carotene and type 2 diabetes (T2D) and related traits. MEDLINE, Embase, and the Cochrane Library were searched for relevant publications up until May 2023. Studies were eligible if they had a cohort, case-control, or randomized controlled trial (RCT) design and examined dietary intake, supplementation, or circulating levels of these antioxidants as exposure, and insulin resistance, β-cell function, or T2D incidence as outcomes. Summary relative risks (RR) or mean differences (MD) with 95% confidence intervals (CI) were estimated using random-effects models. The certainty of the evidence was assessed with the Grading of Recommendations, Assessment, Development and Evaluations framework. Among 6190 screened records, 25 prospective observational studies and 15 RCTs were eligible. Inverse associations were found between dietary and circulating antioxidants and T2D (observational studies). The lowest risk was seen at intakes of 70 mg/d of vitamin C (RR: 0.76; CI: 0.61, 0.95), 12 mg/d of vitamin E (RR: 0.72; CI: 0.61, 0.86), and 4 mg/d of β-carotene (RR: 0.78; CI: 0.65, 0.94). Supplementation with vitamin E (RR: 1.01; CI: 0.93, 1.10) or β-carotene (RR: 0.98; CI: 0.90, 1.07) did not have a protective effect on T2D (RCTs), and data on vitamin C supplementation was limited. Regarding insulin resistance, higher dietary vitamin C (RR: 0.85; CI: 0.74, 0.98) and vitamin E supplementation (MD: -0.35; CI: -0.65, -0.06) were associated with a reduced risk. The certainty of evidence was high for the associations between T2D and dietary vitamin E and β-carotene, and low to moderate for other associations. In conclusion, moderate intakes of vitamins C, E, and β-carotene may lower risk of T2D by reducing insulin resistance. Lack of protection with supplementation in RCTs suggests that adequate rather than high intakes may play a role in T2D prevention. This systematic review and meta-analysis was registered in PROSPERO with registration number CRD42022343482.

Genetic prediction of micronutrient levels and the risk of colorectal polyps: A mendelian randomization study

OBJECTIVE

Previous epidemiological and experimental studies have yielded conflicting results regarding the influence of human micronutrient levels on the risk of colorectal polyps (CP). In our study, we conducted a two-sample Mendelian randomization (MR) investigation to probe the link between 13 human micronutrients (calcium, selenium, magnesium, phosphorus, folate, vitamins B-6, B-12, C, D, beta-carotene, iron, zinc, and copper) and the genetic susceptibility to CP.

METHODS

Summary statistics for CP (n = 463,010) were obtained from pan-European genome-wide association studies, and instrumental variables for 13 micronutrients were screened from published genome-wide association studies (GWAS). After selecting suitable instrumental variables, we performed a two-sample MR study, deploying sensitivity analyses to judge heterogeneity and pleiotropy, using inverse variance weighted methods as our primary estimation tool.

RESULTS

Our study identified that a genetic predisposition to elevated toenail and circulating selenium or serum β-carotene concentrations lowers the risk of CP occurrence. However, no statistically significant association was observed between the other 11 micronutrients and the risk of CP.

CONCLUSION

The study findings provide evidence that the micronutrient selenium and β-carotene may confer protective effects against the development of CP.

Metabolic Pathway Coupled with Fermentation Process Optimization for High-Level Production of Retinol in Yarrowia lipolytica

Retinol is a lipid-soluble form of vitamin A that is crucial for human visual and immune functions. The production of retinol through microbial fermentation has been the focus of recent exploration. However, the obtained titer remains limited and the product is often a mixture of retinal, retinol, and retinoic acid, necessitating purification. To achieve efficient biosynthesis of retinol in Yarrowia lipolytica, we improved the metabolic flux of β-carotene to provide sufficient precursors for retinol in this study. Coupled with the optimization of the expression level of β-carotene 15,15'-dioxygenase, de novo production of retinol was achieved. Furthermore, Tween 80 was used as an extractant and butylated hydroxytoluene as an antioxidant to extract intracellular retinol and prevent retinol oxidation, respectively. This strategy significantly increased the level of retinol production. By optimizing the enzymes converting retinal to retinol, the proportion of extracellular retinol in the produced retinoids reached 100%, totaling 1042.3 mg/L. Finally, total retinol production reached 5.4 g/L through fed-batch fermentation in a 5 L bioreactor, comprising 4.2 g/L extracellular retinol and 1.2 g/L intracellular retinol. This achievement represents the highest reported titer so far and advances the industrial production of retinol.

Enhanced efficacy of β-carotene loaded solid lipid nanoparticles optimized and developed via central composite design on breast cancer cell lines

β-carotene is obtained from both plants and animals and has been the subject of intense research because of its provitamin-A, antioxidant, and anticancer effects. Its limited absorption and oxidative degradation significantly reduce its antitumor efficacy when taken orally. In our study, we utilize a central composite design to develop "bio-safe and highly bio-compatible" solid lipid nanoparticles (SLNs) by using only the combination of palmitic acid and poloxamer-407, a block co-polymer as a surfactant. The current research aim to develop and characterize SLNs loaded with β-carotene to improve their bioavailability and therapeutic efficacy. In addition, the improved cytotoxicity of solid lipid nanoparticles loaded with β-carotene was screened in-vitro in human breast cancer cell lines (MCF-7). The nanoparticles exhibits good stability, as indicated by their mean zeta potential of -26.3 ± 1.3 mV. The particles demonstrated high drug loading and entrapment capabilities. The fabricated nanoparticle's prolonged release potential was shown by the in-vitro release kinetics, which showed a first-order release pattern that adhered to the Higuchi model and showed a slow, linear, and steady release over 48 h. Moreover, a diffusion-type release mechanism was used to liberate β-carotene from the nanoparticles. For six months, the nanoparticles also showed a notable degree of physical stability. Lastly, using the MTT assay, the anti-cancer properties of β-carotene-loaded solid lipid nanoparticles were compared with intact β-carotene on MCF-7 cell lines. The cytotoxicity tests have shown that the encapsulation of β-carotene in the lipid bilayers of the optimized formulation does not interfere with the anti-cancer activity of the drug. When compared to standard β-carotene, β-carotene loaded SLNs showed enhanced anticancer efficacy and it is a plausible therapeutic candidate for enhancing the solubility of water-insoluble and degradation-sensitive biotherapeutics like β-carotene.

Ochratoxin A (OTA) causes intestinal aging damage through the NLRP3 signaling pathway mediated by calcium overload and oxidative stress

Ochratoxin A (OTA) is a widespread environmental toxin that poses a serious threat to human and animal health. OTA has been shown to cause cellular and tissue damage and is a global public health problem. However, the effects of OTA on gastrointestinal aging have not been reported. The aim of this study was to investigate the effects of OTA on intestinal aging in vitro and in vivo. In vitro experiments showed that OTA induced cellular inflammation through calcium overload and oxidative stress, significantly up-regulated the expression of P16, P21, and P53 proteins, markedly increased senescence-associated β-galactosidase activity (SA-β-gal) positive cells, and obviously decreased the expression of proliferating cell nuclear antigen (PCNA) proteins, which led to intestinal cell senescence. Meanwhile, we found that treatment with β-carotene ameliorated OTA-induced intestinal cell senescence. Consistent with the results of the in vitro experiments, in vivo studies showed that the intestinal aging of mice fed OTA was significantly higher than that of the control group. In conclusion, OTA may induce intestinal aging through calcium overload, oxidative stress and inflammation. This study lays a foundation for further research on the toxicological effects of OTA.

Vitamin C, vitamin E, β-carotene and risk of Parkinson's disease: a systematic review and dose-response meta-analysis of observational studies

OBJECTIVE

This study aimed to explore the relationship between the intake of vitamin C, vitamin E and β-carotene, and the risk of Parkinson's disease (PD).

METHODS

Web of Science, Embase, PubMed, Cochrane library, CNKI, and WanFang databases were searched from inception to 29 August 2022 for observational studies reporting the odds ratios (ORs) or relative risks (RRs) or hazard ratios (HRs) and 95% confidence intervals (CIs) of PD by Vitamin C/Vitamin E/β-carotene intake. Random-effects models, publication bias assessment, subgroup, sensitivity and dose-response analyses were performed, using.Stata version 12.0.

RESULTS

A total of 13 studies were included. There was no significant association between high-dose vitamin C intake and the risk of PD compared with low-dose vitamin C intake (RR = 0.98, 95%CI:0.89,1.08). Compared with low-dose intake, high-dose intake of vitamin E can prevent the risk of PD (RR = 0.87, 95%CI:0.77,0.99). Compared with lower β-carotene intake, there was a borderline non-significant correlation between higher intake and PD risk (RR = 0.91, 95%CI:0.82,1.01), and high dose β-carotene intake was found to be associated with a lower risk of PD in women (RR = 0.78, 95%CI:0.64,0.96).

CONCLUSION

This study shows that vitamin E intake can reduce the risk of PD and play a preventive role.

Higher serum carotenoid concentrations were associated with the lower risk of cancer-related death: Evidence from the National Health and Nutrition Examination Survey

The study focuses on the association between serum carotenoids and cancer-related death. Using data from the National Health and Nutrition Examination Survey (2001-2006 and 2017-2018), the study encompasses 10,277 participants older than age 20 years, with recorded baseline characteristics and serum carotenoid concentrations (including α-carotene, trans-β-carotene, cis-β-carotene, β-cryptoxanthin, trans-lycopene, and lutein/zeaxanthin). We hypothesized that serum carotenoid concentrations were negatively associated with cancer-related death. The weighted chi-square analyses indicate significant negative correlations between higher serum concentrations of α-carotene, β-cryptoxanthin, trans-lycopene, and total carotenoids, and the risk of cancer-related deaths. Using weighted Cox regression analysis, this study confirms that α-carotene, β-cryptoxanthin, trans-lycopene, and total carotenoids, as continuous or categorical variables, are inversely related to cancer mortality (P < .0001). Furthermore, considering competitive risk events, lower concentrations of serum β-cryptoxanthin (Fine-Gray P = 1.12e-04), trans-lycopene (P = 5.68e-14), and total carotenoids (P = .03) are associated with an increased risk of cancer-related deaths. The research reveals a crucial inverse relationship between serum carotenoid concentrations and cancer-related death.

Preparation of Edible Colorant Lake Using Calcium Carbonate and β-Carotene: Structural Characterization and Formation Mechanism Study

This study prepared a novel β-carotene colorant lake using calcium carbonate (CaCO3) and investigated the lake formation process and its basic characteristics. Kinetic adsorption analysis confirmed that medium pH (9.3) and medium temperature (40 °C) were more suitable for lake preparation, while desorption occurred, possibly due to crystalline transformation of CaCO3. The isothermal analysis and model fitting results suggested that the β-carotene and CaCO3 particles combined via a monolayer adsorption process driven by physical force. Electrostatic attraction likely participated in the process due to the net negative surface charges of β-carotene dispersion and positively charged groups on the CaCO3 particle surfaces. Ethanol, ultrasonic treatment, and drying method significantly influenced the immobilization efficiency (IE) of β-carotene in the lake and light stability of the lake, without affecting its crystal form. The thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) curves confirmed absorption of β-carotene onto CaCO3. Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses indicated no obvious chemical bonds between β-carotene and CaCO3. Energy-dispersive spectroscopy (EDS) confirmed the presence of β-carotene on surfaces but not in the interior of the CaCO3 particles. The adsorption of β-carotene by calcium carbonate was further confirmed to be a physical adsorption on surface.

Biomimetic SERS substrate with silicon-mediated internal standard: Improved sensing of environmental pollutants and nutrients

Biomimetic materials with fascinating natural micro-nano surface structures offer a good choice for the simple fabrication of surface-enhanced Raman scattering (SERS) substrate. This study presented a novel sodium carboxymethylcellulose (NaCMC)-Ag biomimetic substrate which was fabricated through the reverse replication of micro-nano structures from cantaloupe peel. Particularly, silicon nanoparticles (Si NPs) were doped into this flexible biomimetic substrate in its fabrication process. Abundant electromagnetic "hotspots" could be effectively excited in this Ag densely covered matrix which maintained numerous protrusions as well as vertical and horizontal grooves. Specifically, the doped Si NPs exhibited a robust intrinsic Raman peak, which could be employed as an internal standard to calibrate the target signal. In this regard, the biomimetic substrate with the optimal electromagnetic enhancement and the quantitative calibration capabilities exhibited a high enhancement factor and a remedied linear relationship in the detection. After a perfect uniformity of signal was proved by the corrected SERS mapping, the biomimetic SERS substrate was finally utilized in the practical analysis of methylene blue (MB) and β-carotene with ultra-low limit of detection, highlighting its importance in practical detection scenarios.

High internal phase emulsions stabilized by whey protein covalently modified with carboxymethyl cellulose: Enhanced environmental stability, storage stability and bioaccessibility

In this work, the effects of whey protein-carboxymethyl cellulose (WP-CMC) conjugates on the environmental stability, in vitro digestion stability, storage stability and bioaccessibility of high internal phase emulsions (HIPEs) were investigated. Compared to the HIPEs stabilized by the mixture of WP and CMC, the HIPEs stabilized by WP-CMC were less sensitive to environmental changes by particle size and zeta-potential, and showed better stability and bioavailability of pine nut oil as well as β-carotene during simulated gastrointestinal digestion. In addition, the inclusion function and pine nut oil oxidative stability of the HIPEs stabilized by WP-CMC were better during 16 days of storage than those of the pine nut oil and HIPEs stabilized by the mixture of WP and CMC, and also expressed higher storage stability of β-carotene. These results suggested that the conjugate-stabilized emulsions developed in this study have potential applications as protectors and carriers of liposoluble active ingredients.

Elevated temperature extraction of β-carotene from freeze-dried carrot powder into sunflower oil: Extraction kinetics and thermal stability

β-Carotene, a precursor of vitamin A, can alleviate the deficiency of this vitamin prevalent worldwide. Earlier research studies have addressed the extraction of β-carotene at relatively low temperatures (up to 70°C) due to its perceived instability at higher temperatures, as a result of which extraction rates recorded are relatively low. This study models the net rate of β-carotene extraction by considering both extraction and degradation kinetics. The model developed, which accounts for degradation occurring in solid and extract phases, has been experimentally validated for the extraction of β-carotene from freeze-dried carrot powder into sunflower oil over a range of temperatures 90-150°C. This study also gives insights into the application of sunflower oil as a carrier for β-carotene during cooking and food processing, by monitoring and modeling the thermal degradation and isomerization of β-carotene at temperatures up to 220°C. The modeling of extraction kinetics shows that it is possible to achieve viable extraction rates by employing temperatures in the range (90-150°C) for relatively short times (<5 min). The degradation kinetics shows that almost 75% of the β-carotene can survive heating at 180°C for 10 min-indicating the possibility of using β-carotene enriched edible oils for frying. This study also reports on the formation of three isomers of β-carotene identified using HPLC: trans-, 9-cis, and 13-cis. The reaction network model developed in this study was able to account for the transient variation of the concentration of all three isomers. PRACTICAL APPLICATION: β-Carotene is a precursor of vitamin A and its consumption can potentially alleviate the deficiency of this vitamin prevalent worldwide. This study validates a model for the extraction of β-carotene in sunflower oil, which takes into account extraction as well as degradation occurring during extraction, so that a rational method is available for the design of efficient extractors for this purpose. This paper also establishes the thermal stability of β-carotene under frying conditions by quantifying its thermal degradation as well as isomerization.

Intelligent and active biodegradable biopolymeric films containing carotenoids

There is growing interest in the use of natural bioactive compounds for the development of new bio-based materials for intelligent and active food packaging applications. Several beneficial effects have been associated with the antioxidant and antimicrobial potentials of carotenoid compounds. In addition, carotenoids are sensitive to pH changes and oxidation reactions, which make them useful bioindicators of food deterioration. This review summarizes the current research on the application of carotenoids as novel intelligent and active biodegradable food packaging materials. Carotenoids recovered from food processing by-products can be used in the development of active food packaging materials due to their antioxidant properties. They help maintain the stability of lipid-rich foods, such as vegetable oils. Additionally, when incorporated into films, carotenoids can monitor food oxidation, providing intelligent functionalities.

Desiccation tolerance in the resurrection plant Barbacenia graminifolia involves changes in redox metabolism and carotenoid oxidation

Desiccation tolerance in vegetative tissues enables resurrection plants to remain quiescent under severe drought and rapidly recover full metabolism once water becomes available. Barbacenia graminifolia is a resurrection plant that occurs at high altitudes, typically growing on rock slits, exposed to high irradiance and limited water availability. We analyzed the levels of reactive oxygen species (ROS) and antioxidants, carotenoids and its cleavage products, and stress-related phytohormones in fully hydrated, dehydrated, and rehydrated leaves of B. graminifolia. This species exhibited a precise adjustment of its antioxidant metabolism to desiccation. Our results indicate that this adjustment is associated with enhanced carotenoid and apocarotenoids, α-tocopherol and compounds of ascorbate-glutathione cycle. While α-carotene and lutein increased in dried-leaves suggesting effective protection of the light-harvesting complexes, the decrease in β-carotene was accompanied of 10.2-fold increase in the content of β-cyclocitral, an apocarotenoid implicated in the regulation of abiotic stresses, compared to hydrated plants. The principal component analysis showed that dehydrated plants at 30 days formed a separate cluster from both hydrated and dehydrated plants for up to 15 days. This regulation might be part of the protective metabolic strategies employed by this resurrection plant to survive water scarcity in its inhospitable habitat.

Assessment of Popcorn's Bioactive Status in Response to Popping

Popcorn is a specialty maize variety with popping abilities. Although considered a snack, popcorn flakes provide a variety of benefits for the human diet. To evaluate the change in content of bioactive compounds in response to microwave popping, the kernels and flakes of twelve popcorn hybrids were assayed. Accordingly, the content of phytic acid, glutathione, phenolic compounds, carotenoids, and tocopherols, as well as the antioxidant activity, were evaluated. In all evaluated popcorn hybrids, the most pronounced significant average decrease of 71.94% was observed for GSH content, followed by 57.72% and 16.12% decreases for lutein + zeaxanthin and phytic acid content, respectively. In response to popping, in the majority of the evaluated hybrids, the most pronounced significant average changes of a 63.42% increase and a 27.61% decrease were observed for DPPH, followed by a 51.52% increase and a 24.48% decrease for β-carotene, as well as, a 48.62% increase and a 16.71% decrease for α-Tocopherol content, respectively. The applied principal component and hierarchical cluster analyses revealed the distinct separation of popcorn hybrids' kernels and flakes, indicating the existence of a unique linkage of changes in bioactive compound content in response to popping.

Preparation, characterization, and release properties of Rosa roxburghii Tratt seed oil and β-carotene-coloaded proliposomes

Rosa roxburghii Tratt seed oil (RSO) and β-carotene (βC) were chosen to prepare proliposomes by the thin-film dispersion method. The characteristics of unloaded proliposome, RSO proliposome (L-R), βC proliposome (L-β), and RSO/βC proliposome (L-R-β) were analyzed, and their antioxidant activity, storage stability, and release properties were investigated. The proliposomes had an encapsulation efficiency (RSO, βC) higher than 83.10%, nanometer size, smooth surface, and irregular structure. L-R-β showed better dispersibility, stability, and antioxidant activity than L-R and L-β. Simultaneous encapsulation of RSO and βC reduced the phospholipid oxidation of proliposomes and improved the retention rate of RSO in storage environments of 4, 25, and 40°C. Moreover, the RSO and βC release kinetics of proliposomes in the simulated saliva fluid and gastric fluid phases can be described by the first-order model, and the Korsmeyr-Peppas method was applied to describe their release mechanism in the simulated intestinal fluid phase.

Pickering emulsions stabilized by ternary complexes involving curcumin-modified zein and polysaccharides with different charge amounts for encapsulating β-carotene

In this research, zein was modified with curcumin to obtain covalent and non-covalent complexes. They were further covered with polysaccharides (gum arabic or gum karaya) possessing different surface charge amounts to obtain ternary nanoparticles for preparing novel antioxidant Pickering emulsions. The addition of curcumin to the zein-polysaccharide system significantly retarded the UV degradation of the encapsulated β-carotene (maximum retention ∼ 97%) and effectively inhibited the lipid oxidation of the emulsions. In vitro gastrointestinal digestion assays showed that gum karaya significantly delayed the release of free fatty acids, thereby improving the bioaccessibility of β-carotene (the highest bioavailability ∼ 38%). By comparing the performance of the complex particles, the weakly charged polysaccharides were superior to the highly charged ones, while zein-curcumin covalent binding was superior to non-covalent binding in the above experiments. This study provides innovative perspectives on the use of novel Pickering emulsions to provide ideal protection and bioavailability of lipophilic nutraceuticals.

The role of dietary carotenoids in preventing the development of esophageal squamous cell carcinoma

Background and aims: Experimental studies showed that carotenoids had anti-carcinogenic properties, but epidemiological studies on the association between dietary carotenoids and esophageal squamous cell carcinoma (ESCC) risk were limited, and the findings were inconsistent. This study aimed to investigate the roles of intake of dietary carotenoids in the development of ESCC among a rural Chinese population. Methods: A population-based case-control study was conducted in Southwest China. A total of 915 incident ESCC cases and 925 community-based controls were included. A validated food frequency questionnaire with 76-item was adopted to collect information about dietary consumption. Intake of dietary calories and each carotenoid was calculated according to the China food composition tables. Odds ratios (OR) with 95% confidence intervals (CI) were calculated by a logistic regression model, with adjustments for age, gender, body mass index, family cancer history, cigarette smoking, alcohol drinking, education, marital status, prudent pattern score, and total calories. Results: In comparison to the highest with lowest intake quartiles, intake of total carotenes (OR: 0.70, 95% CI: 0.52-0.96, Ptrend: 0.024), α-carotene (OR: 0.62, 95% CI: 0.46-0.83, Ptrend: 0.014), β-carotene (OR: 0.63, 95% CI: 0.46-0.86, P-trend: 0.005), and the sum of lutein and zeaxanthin (OR: 0.41, 95% CI: 0.29-0.56, Ptrend<0.001) was significantly associated with a decreased risk of ESCC after adjustment for confounders. Conclusions: The results indicated that a higher intake of total carotene, α-carotene, β-carotene, and the sum of lutein and zeaxanthin was associated with a lower risk of ESCC.

Discovery of ultra-weakly coupled β-carotene J-aggregates by machine learning

Carotenoid aggregates are omnipresent in natural world and can be synthesized in hydrophilic environments. Despite different types of carotenoid aggregates have been reported hitherto, the way to predict the formation of carotenoid aggregates, i.e. H- or J-aggregates, is still challenging. Here, for the first time, we established machine learning models that can predict the formation behavior of carotenoid aggregates. The models are trained based on a database containing different types of carotenoid aggregates reported in the literatures. With the help of these machine learning models, we found a series of unknown types of β-carotene J-aggregates. These novel aggregates are ultra-weakly coupled and have absorption bands up to 700 nm, different from all the carotenoid aggregates reported previously. Our work demonstrates that the machine learning is a powerful tool to predict the formation behavior of carotenoid aggregates and can further lead into the discovery of new carotenoid aggregates for different applications.

15-cis-Phytoene Desaturase and 15-cis-Phytoene Synthase Can Catalyze the Synthesis of β-Carotene and Influence the Color of Apricot Pulp

Fruit color affects its commercial value. β-carotene is the pigment that provides color for many fruits and vegetables. However, the molecular mechanism of β-carotene metabolism during apricot ripening is largely unknown. Here, we investigated whether β-carotene content affects apricot fruit color. First, the differences in β-carotene content between orange apricot 'JTY' and white apricot 'X15' during nine developmental stages (S1-S9) were compared. β-carotene contents highly significantly differed between 'JTY' and 'X15' from S5 (color transition stage) onwards. Whole-transcriptome analysis showed that the β-carotene synthesis genes 15-cis-phytoene desaturase (PaPDS) and 15-cis-phytoene synthase (PaPSY) significantly differed between the two cultivars during the color transition stage. There was a 5 bp deletion in exon 11 of PaPDS in 'X15', which led to early termination of amino acid translation. Gene overexpression and virus-induced silencing analysis showed that truncated PaPDS disrupted the β-carotene biosynthesis pathway in apricot pulp, resulting in decreased β-carotene content and a white phenotype. Furthermore, virus-induced silencing analysis showed that PaPSY was also a key gene in β-carotene biosynthesis. These findings provide new insights into the molecular regulation of apricot carotenoids and provide a theoretical reference for breeding new cultivars of apricot.

Mimicking Natural Antioxidant Systems for Improved Photostability in Wide-Band-Gap Perovskite Solar Cells

Fostered by the top power conversion efficiencies (PCEs) of lab-scale devices, industrialization of perovskite solar cells is underway. Nevertheless, the intrinsically poor stability of these materials still represents a major concern. Herein, inspired by Nature, the use of β-carotene in perovskite solar cells is proposed to mimic its role as a protective pigment, as occurs in natural photosynthesis. Laser-mediated photostability (LMPS) assessment, Fourier-transform infrared spectra analysis acquired in attenuate total reflectance (ATR-FTIR), spectroscopy ellipsometry (SE), and time-resolved photoluminescence (TRPL) measurements under stress conditions prove that the inclusion of a thin β-carotene interlayer promotes a high improvement in the photostability of the perovskite films against photooxidation. Importantly, this is accompanied by an improvement of the solar cell PCE that approaches 20% efficiency with no hysteresis, which is among the highest values reported for a mixed halide (I-Br) perovskite with a band gap of 1.74 eV, relevant for coupling with silicon in tandem cells.

Bioaccessibility of Carotenoids and Polyphenols in Organic Butternut Squash (Cucurbita moschata): Impact of Industrial Freezing Process

Butternut squash (Cucurbita moschata) is recognized as a functional food due to its abundant content of health-promoting compounds, including carotenoids and polyphenols. The aim of this study was to examine the impact of industrial freezing stages on the bioaccessibility of carotenoids and polyphenols in organic Butternut squash supplied for baby food. Identification and quantification of bioactive compounds were carried out using UPLC-ESI-MS/MS and HPLC-PDA, respectively. The results revealed that industrial freezing of squash did not cause a significant change in bioaccessibility of α- and β-carotene. On the other hand, frozen squash was found to contain higher levels of bioaccessible epicatechin (main flavonoid) (117.5 mg/kg) and syringic acid (main phenolic acid) (32.0 mg/kg) compared to fresh internal fruit. Moreover, the levels of bioaccessible epicatechin and syringic acid were found to be the highest in discarded pomace and seed sample (454.0 and 132.4 mg/kg, respectively). Overall, this study emphasized that industrial freezing could be an effective strategy for preserving carotenoid bioaccessibility in organic Butternut squash, while also enhancing the levels of bioaccessible polyphenols. In addition, we also demonstrated that pomace and seed, which are discarded as waste, have significant potential to be utilized as a food source rich in bioactive compounds.

Gac Fruit Oils Encapsulated by Palm Oil-based Monoacylglycerols: The Effect of Drying Methods

Lyotropic liquid crystals (LLCs) are interesting wall-materials for encapsulation technology, in which monoacylglycerols (MAGs) are considered as potential ingredient for LLC formulation. This study, therefore, applied palm oil-based MAGs to encapsulate Gac fruit oils and compared the effect of two drying methods (freeze-drying and spray-drying) on the quality of products during storage. Wall-materials were prepared by ultrasound dispersing MAGs/water mixtures (40/60, w/w) into Pluronic solution (2%, w/w) to formulate LLC dispersions. Then, Gac fruit oils were encapsulated by freeze-drying and spray-drying. Various technologies were applied to characterize the properties of dispersions, the encapsulated powder morphology and the loading capacity. Obtained results showed that LLC dispersions made of palm oilbased MAG were micro- and nano-emulsions which were very convenient for encapsulating Gac fruit oils. For both drying methods, β-carotene of Gac fruit oils was successfully entrapped by MAGs with a high loading capacity (200 µg β-carotene/g powder). The degradation of encapsulated β-carotene after four storage weeks was 10 - 40% and freeze-dried samples showed a better protection effect in comparison to spray-dried samples.

The Association between Circulating Carotenoids and Risk of Breast Cancer: A Systematic Review and Dose-Response Meta-Analysis of Prospective Studies

Carotenoids appear to have anticancer effects. Prospective evidence for the relation between serum carotenoids and breast cancer is controversial. The present systematic review and meta-analysis aimed to investigate the link between circulating carotenoids and the risk of breast cancer. We performed a systematic search of PubMed, Scopus, and Web of Science up to 30 November, 2022. Prospective studies on adults aged ≥18 y that have reported risk estimates for the association between circulating carotenoids and breast cancer risk were considered. Study quality was assessed using the Newcastle-Ottawa Scale. A random-effects model was used for combining studies' risk estimates. Dose-response relations were explored through a 1-stage random-effects model. Fifteen publications (17 nested case-control studies and 1 cohort study) with 20,188 participants and 7608 cases were included. We observed an inverse association between the highest level of circulating total carotenoids (relative risk [RR]: 0.76; 95% confidence interval [CI]: 0.62, 0.93; n = 8), α-carotene (RR: 0.77; 95% CI: 0.68, 0.87; n = 13), β-carotene (RR: 0.80; 95% CI: 0.65, 0.98; n = 15), β-cryptoxanthin (RR: 0.85; 95% CI: 0.74, 0.96; n = 11), lycopene (RR: 0.86; 95% CI: 0.76, 0.98; n = 13), and lutein (RR: 0.70; 95% CI: 0.52, 0.93; n = 6) and the risk of breast cancer compared with the lowest level. Additionally, each 10 μg/dL of total carotenoids, α-carotene, β-carotene, and β-cryptoxanthin was associated with 2%, 22%, 4%, and 10% lower risk of breast cancer, respectively. This relationship was stronger at lower levels of total carotenoids and β-cryptoxanthin. The certainty of evidence was rated from very low to low. Most studies were performed among Western nations, which should be acknowledged for extrapolation of findings. Total circulating carotenoids, α-carotene, β-carotene, β-cryptoxanthin, lycopene, and lutein seem to be related to a decreased risk of breast cancer. Our findings could have practical importance for public health. This study was registered at PROSPERO as CRD42023434983.

Antioxidant Vitamin Intake and LOX-Index in Japanese Municipal Workers

Antioxidant vitamin intake has been reported to be associated with decreased risk of cardiovascular diseases. To date, however, no study has examined the association between antioxidant vitamin intake and LOX-index, a predictive biomarker of cardiovascular disease. We investigated the cross-sectional association between antioxidant vitamin (α-carotene, β-carotene, α-tocopherol, and vitamin C) intake and LOX-index in Japanese municipal workers. Participants were 346 workers (171 men and 175 women aged 19-71 y) who received a health check-up and participated in a nutrition and health survey. Antioxidant vitamin intake was assessed using a validated brief self-administered diet history questionnaire. LOX-index was calculated by multiplying serum concentrations of the soluble form of lectin-like oxidized LDL receptor 1 by those of LOX-1 ligands containing apolipoprotein B. Multiple regression analysis was used to estimate the geometric mean of LOX-index according to tertile of each antioxidant vitamin intake. Overall, α-carotene, β-carotene, α-tocopherol, and vitamin C intake were not associated with LOX-index. However, in stratified analyses by sex, geometric means of LOX-index tended to decrease with antioxidant vitamin intake in women, but not in men. The geometric means of LOX-index for the lowest through highest tertile of α-carotene intake were 771 (604-984), 639 (511-799), and 564 (469-677) (p for trend=0.07). Our results suggest that there is no association between antioxidant vitamin intake and LOX-index in Japanese workers. The suggestive inverse association between antioxidant vitamin intake and LOX-index in women warrants further investigation.

Development of a Gene-Based Marker Set for Orange-Colored Watermelon Flesh with a High β-Carotene Content

The fruit flesh of watermelons differs depending on the distinct carotenoid composition. Orange-colored flesh relates to the accumulation of β-carotene, which is beneficial to human health. Canary-yellow-fleshed OTO-DAH and orange-β-fleshed (orange-fleshed with high β-carotene) NB-DAH near-isogenic lines (NILs) were used to determine the genetic mechanism attributed to orange watermelon flesh. For genetic mapping, an F2 population was developed by crossing the two NILs. The segregation ratio of flesh color in the F2 population indicated that the orange-β flesh of the NB-DAH NIL was controlled by a single incompletely dominant gene. Through a comparative analysis of the whole-genome sequences of the parent lines and NILs, a major introgression region unique to the NB-DAH NIL was detected on Chr. 1; this was considered a candidate region for harboring genes that distinguish orange from canary-yellow and red flesh. Among the 13 genes involved in the carotenoid metabolic pathway in watermelons, only ClPSY1 (ClCG01G008470), which encodes phytoene synthase 1, was located within the introgression region. The genotyping of F2 plants using a cleaved amplified polymorphic sequence marker developed from a non-synonymous SNP in ClPSY1 revealed its relationship with orange-β flesh. The insights gained in this study can be applied to marker-assisted breeding for this desirable trait.

Production of carotenoids from aromatics and pretreated lignocellulosic biomass by Novosphingobium aromaticivorans

IMPORTANCE

There is economic and environmental interest in generating commodity chemicals from renewable resources, such as lignocellulosic biomass, that can substitute for chemicals derived from fossil fuels. The bacterium Novosphingobium aromaticivorans is a promising microbial platform for producing commodity chemicals from lignocellulosic biomass because it can produce these from compounds in pretreated lignocellulosic biomass, which many industrial microbial catalysts cannot metabolize. Here, we show that N. aromaticivorans can be engineered to produce several valuable carotenoids. We also show that engineered N. aromaticivorans strains can produce these lipophilic chemicals concurrently with the extracellular commodity chemical 2-pyrone-4,6-dicarboxylic acid when grown in a complex liquor obtained from alkaline pretreated lignocellulosic biomass. Concurrent microbial production of valuable intra- and extracellular products can increase the economic value generated from the conversion of lignocellulosic biomass-derived compounds into commodity chemicals and facilitate the separation of water- and membrane-soluble products.

Retinoic Acid-PPARα Mediates β-Carotene Resistance to Placental Dysfunction Induced by Deoxynivalenol

Deoxynivalenol (DON), one of the most polluted mycotoxins in the environment and food, has been proven to have strong embryonic and reproductive toxicities. However, the effects of DON on placental impairment and effective interventions are still unclear. This study investigated the effect of β-carotene on placental functional impairment and its underlying molecular mechanism under DON exposure. Adverse pregnancy outcomes were caused by intraperitoneal injection of DON from 13.5 to 15.5 days of gestation in mice, resulting in higher enrichment of DON in placenta than in other tissue samples. Interestingly, 0.1% β-carotene dietary supplementation could significantly alleviate DON-induced pregnancy outcomes. Additionally, in vivo and in vitro placental barrier models demonstrated the association of DON-induced placental function impairment with placental permeability barrier disruption, angiogenesis impairment, and oxidative stress induction. Moreover, β-carotene regulated DON-induced placental toxicity by activating the expressions of claudin 1, zonula occludens-1, and vascular endothelial growth factor-A through retinoic acid-peroxisome proliferator-activated receptor α signaling.

nov., a novel β-carotene-producing bacterium that alleviates salinity stress in Arabidopsis

A novel endophytic bacterium, designated DY-R2A-6T, was isolated from oat (Avena sativa L.) seeds and found to produces β-carotene. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain DY-R2A-6T had 96.3% similarity with Jiella aquimaris LZB041T, 96.0% similarity with Aurantimonas aggregate R14M6T and Aureimonas frigidaquae JCM 14755T, and less than 95.8% similarity with other genera in the family Aurantimonadaceae. The complete genome of strain DY-R2A-6T comprised 5,929,370 base pairs, consisting of one full chromosome (5,909,198 bp) and one plasmid (20,172 bp), with a G + C content was 69.1%. The overall genome-related index (OGRI), including digital DNA-DNA hybridization (<20.5%), ANI (<79.2%), and AAI (<64.2%) values, all fell below the thresholds set for novel genera. The major cellular fatty acids (>10%) of strain DY-R2A-6T were C16:0, C19:0 cyclo ω8c, and summed feature 8 (C18:1ω7c and/or C18:1ω6c). Ubiquinone-10 was the main respiratory quinone. We identified the gene cluster responsible for carotenoid biosynthesis in the genome and found that the pink-pigment produced by strain DY-R2A-6T is β-carotene. In experiment with Arabidopsis seedlings, co-cultivation with strain DY-R2A-6T led to a 1.4-fold increase in plant biomass and chlorophyll content under salt stress conditions, demonstrating its capacity to enhance salt stress tolerance in plants. Moreover, external application of β-carotene to Arabidopsis seedlings under salt stress conditions also mitigated the stress significantly. Based on these findings, strain DY-R2A-6T is proposed to represent a novel genus and species in the family Aurantimonadaceae, named Jeongeuplla avenae gen. nov., sp. nov. The type strain is DY-R2A-6T (= KCTC 82985T = GDMCC 1.3014T). This study not only identified a new taxon but also utilized genome analysis to predict and confirm the production of β-carotene by strain DY-R2A-6T. It also demonstrated the ability of this strain to enhance salt stress tolerance in plants, suggesting potential application in agriculture to mitigate environmental stress in crops.

Advances in the Discovery and Engineering of Gene Targets for Carotenoid Biosynthesis in Recombinant Strains

Carotenoids are naturally occurring pigments that are abundant in the natural world. Due to their excellent antioxidant attributes, carotenoids are widely utilized in various industries, including the food, pharmaceutical, cosmetic industries, and others. Plants, algae, and microorganisms are presently the main sources for acquiring natural carotenoids. However, due to the swift progress in metabolic engineering and synthetic biology, along with the continuous and thorough investigation of carotenoid biosynthetic pathways, recombinant strains have emerged as promising candidates to produce carotenoids. The identification and manipulation of gene targets that influence the accumulation of the desired products is a crucial challenge in the construction and metabolic regulation of recombinant strains. In this review, we provide an overview of the carotenoid biosynthetic pathway, followed by a summary of the methodologies employed in the discovery of gene targets associated with carotenoid production. Furthermore, we focus on discussing the gene targets that have shown potential to enhance carotenoid production. To facilitate future research, we categorize these gene targets based on their capacity to attain elevated levels of carotenoid production.

Polysaccharides affect the utilization of β-carotene through gut microbiota investigated by in vitro and in vivo experiments

This study aimed to evaluate the effects of six polysaccharides on the utilization of β-carotene from the perspective of gut microbiota using both in vitro simulated anaerobic fermentation systems and in vivo animal experiments. In the in vitro experiments, the addition of arabinoxylan, arabinogalactan, mannan, inulin, chitosan, and glucan led to a 31.07-79.12% decrease in β-carotene retention and a significant increase in retinol content (0.21-0.99-fold) compared to β-carotene alone. Among them, the addition of chitosan produced the highest level of retinol. In the in vivo experiments, mice treated with the six polysaccharides exhibited a significant increase (2.51-5.78-fold) in serum β-carotene content compared to the group treated with β-carotene alone. The accumulation of retinoids in the serum, liver, and small intestine increased by 13.56-21.61%, 12.64-56.27%, and 7.9%-71.69%, respectively. The expression of β-carotene cleavage enzymes was increased in the liver. Genetic analysis of small intestinal tissue revealed no significant enhancement in the expression of genes related to β-carotene metabolism. In the gut microbiota environment, the addition of polysaccharides generated more SCFAs and altered the structure and composition of the gut microbiota. The correlation analysis revealed a strong association between gut microbes (Ruminococcaceae and Odoribacteraceae) and β-carotene metabolism and absorption. Collectively, our findings suggest that the addition of polysaccharides may improve β-carotene utilization by modulating the gut microbiota.

Advancing carotenoid Quantification: A new method for semi-quantitative assessment of β -Carotene and lycopene content in food extracts

Carotenoids, such as lycopene and β-carotene, have been widely recognized for their antioxidant properties and potential health benefits. Accurate quantification of carotenoids in plant extracts is essential for nutritional assessment, quality control, and research investigations. This study introduces an innovative method for quantifying lycopene and β-carotene, in plant extracts and aims to bridge the gap between complex and expensive carotenoid quantification techniques and the need for accessible methods that can be widely adopted. The primary difference between HPLC and HPTLC lies in the medium used for separation. HPLC employs a liquid phase within columns, while HPTLC utilizes a thin layer of adsorbent on a plate. This distinction impacts factors like equipment, cost, and analysis time. The VisionCats software, combined with the CAMAG Visualizer-2, allows the semi-quantification of metabolites using an image-based evaluation method enabling the simultaneous assessment of qualitative and semi-quantitative information from the HPTLC images. Sample preparation involves washing and drying the vegetal material, followed by dichloromethane extraction. HPTLC analysis is performed using the CAMAG Advanced Herbal System, and the validation studies include establishing calibration curves and determining the detection threshold and minimum quantification threshold for lycopene and β-carotene. Specificity and precision were evaluated to ensure accurate identification and repeatability of the method. Data analysis involves selecting the regression method based on the nature of the data and assessing the goodness of fit using the R2 value. The results showed distinct peaks corresponding to lycopene and β-carotene in the chromatograms of the plant extract samples. The visualizer-based method demonstrates good specificity and precision, with no interfering peaks observed and low relative standard deviation. The method shows promising results regarding specificity, precision, and reliability. It has the potential for broader implementation in carotenoid research and rapid monitoring of carotenoid content in various agricultural and food products, particularly in resource-limited settings. Further optimization and validation on a wider range of samples would enhance the applicability of this method in carotenoid research. Sample preparation involves washing and drying the vegetal material, followed by dichloromethane extraction. HPTLC analysis is performed using the CAMAG Advanced Herbal System, and the validation studies include establishing calibration curves and determining the detection threshold and minimum quantification threshold for lycopene and β-carotene. Specificity and precision were evaluated to ensure accurate identification and repeatability of the method. Data analysis involves selecting the regression method based on the nature of the data and assessing the goodness of fit using the R2 value. The results showed distinct peaks corresponding to lycopene and β-carotene in the chromatograms of the plant extract samples. The visualizer-based method demonstrates good specificity and precision, with no interfering peaks observed and low relative standard deviation. The method shows promising results regarding specificity, precision, and reliability. It has the potential for broader implementation in carotenoid research and for rapid screening and monitoring of carotenoid content in various agricultural and food products, particularly in resource-limited settings. Further optimization and validation on a wider range of samples would enhance the applicability of this method in carotenoid research.

Integrated fermentative process for lipid and β-carotene production from acetogenic syngas fermentation using an engineered oleaginous Yarrowia lipolytica yeast

An engineered Yarrowia lipolytica strain was successfully employed to produce β-carotene and lipids from acetic acid, a product of syngas fermentation by Clostridium aceticum. The strain showed acetic acid tolerance up to concentrations of 20 g/L. Flask experiments yielded a peak lipid content of 33.7 % and β-carotene concentration of 13.6 mg/g under specific nutrient conditions. The study also investigated pH effects on production in bioreactors, revealing optimal lipid and β-carotene contents at pH 6.0, reaching 22.9 % and 44 mg/g, respectively. Lipid profiles were consistent across experiments, with C18:1 being the dominant compound at approximately 50 %. This research underscores a green revolution in bioprocessing, showing how biocatalysts can convert syngas, a potentially polluting byproduct, into valuable β-carotene and lipids with a Y. lipolytica strain.

Study of the Anti-Inflammatory Mechanism of β-Carotene Based on Network Pharmacology

β-carotene is known to have pharmacological effects such as anti-inflammatory, antioxidant, and anti-tumor properties. However, its main mechanism and related signaling pathways in the treatment of inflammation are still unclear. In this study, component target prediction was performed by using literature retrieval and the SwissTargetPrediction database. Disease targets were collected from various databases, including DisGeNET, OMIM, Drug Bank, and GeneCards. A protein-protein interaction (PPI) network was constructed, and enrichment analysis of gene ontology and biological pathways was carried out for important targets. The analysis showed that there were 191 unique targets of β-carotene after removing repeat sites. A total of 2067 targets from the three databases were integrated, 58 duplicate targets were removed, and 2009 potential disease action targets were obtained. Biological function enrichment analysis revealed 284 biological process (BP) entries, 31 cellular component (CC) entries, 55 molecular function (MF) entries, and 84 cellular pathways. The biological processes were mostly associated with various pathways and their regulation, whereas the cell components were mainly membrane components. The main molecular functions included RNA polymerase II transcription factor activity, DNA binding specific to the ligand activation sequence, DNA binding, steroid binding sequence-specific DNA binding, enzyme binding, and steroid hormone receptors. The pathways involved in the process included the TNF signaling pathway, sphingomyelin signaling pathway, and some disease pathways. Lastly, the anti-inflammatory signaling pathway of β-carotene was systematically analyzed using network pharmacology, while the molecular mechanism of β-carotene was further explored by molecular docking. In this study, the anti-inflammatory mechanism of β-carotene was preliminarily explored and predicted by bioinformatics methods, and further experiments will be designed to verify and confirm the predicted results, in order to finally reveal the anti-inflammatory mechanism of β-carotene.

Basking in the sun: how mosses photosynthesise and survive in Antarctica

The Antarctic environment is extremely cold, windy and dry. Ozone depletion has resulted in increasing ultraviolet-B radiation, and increasing greenhouse gases and decreasing stratospheric ozone have altered Antarctica's climate. How do mosses thrive photosynthetically in this harsh environment? Antarctic mosses take advantage of microclimates where the combination of protection from wind, sufficient melt water, nutrients from seabirds and optimal sunlight provides both photosynthetic energy and sufficient warmth for efficient metabolism. The amount of sunlight presents a challenge: more light creates warmer canopies which are optimal for photosynthetic enzymes but can contain excess light energy that could damage the photochemical apparatus. Antarctic mosses thus exhibit strong photoprotective potential in the form of xanthophyll cycle pigments. Conversion to zeaxanthin is high when conditions are most extreme, especially when water content is low. Antarctic mosses also produce UV screening compounds which are maintained in cell walls in some species and appear to protect from DNA damage under elevated UV-B radiation. These plants thus survive in one of the harshest places on Earth by taking advantage of the best real estate to optimise their metabolism. But survival is precarious and it remains to be seen if these strategies will still work as the Antarctic climate changes.

Deposition and bioconversion law of β-carotene in laying hens after long-term supplementation under adequate vitamin A status in the diet

β-Carotene, because it is the precursor of vitamin A and has versatile biological roles, has been applied as a feed additive in the poultry industry for a long time. In this study, we investigated the deposition and bioconversion of β-carotene in laying hens. A total of 600 Hy-line brown laying hens at 40 wk of age were randomly divided into 5 dietary treatments, each group's dietary supplemental levels of β-carotene were 0, 15, 30, 60, 120 mg/kg feed, and the vitamin A levels were all 8,000 IU/kg. After 14-wk trial, samples were collected, then carotenoids and different forms of vitamin A were detected using the novel method developed by our laboratory. We found that dietary β-carotene treatment had no significant effects on laying hens' production performance and egg quality (P > 0.05), except the yolk color. The deposition of β-carotene in the body gradually increased (P < 0.01) with the supplemental dose, whereas the contents of lutein and zeaxanthin decreased (P < 0.05). When the β-carotene supplemental level was above 30 mg/kg in the diet, the different forms of vitamin A in in serum, liver, ovary, and yolks were increased compared to the control group (P < 0.05). However, these indicators decreased when the additional dose was 120 mg/kg. Moreover, the mRNA levels of the genes involved in β-carotene absorption, bioconversion, and negative feedback regulation in duodenal mucosa and liver were upregulated after long-term feeding (P < 0.05). Histological staining of the ovaries indicated that the deposition of β-carotene led to a lower rate of follicle atresia (P < 0.05), and this positive effects may be related to the antioxidant function of β-carotene, which caused a reduction of oxidation products in the ovary (P < 0.05). Altogether, β-carotene could accumulate in laying hens intactly and exert its biological functions in tissue. Meanwhile, a part of β-carotene could also be converted into vitamin A but this bioconversion has an upper limit and negative feedback regulation.

First Optimization of Tomato Pomace in Diets for Tenebrio molitor (L.) (Coleoptera: Tenebrionidae)

Tomato pomace (TP), an agricultural industrial waste product from the tomato processing industry, is valorized as a rearing substrate for Tenebrio molitor (L.). This study evaluated bran-based diets with increasing tomato pomace (0%, 27%, 41%, and 100%). Protein sources, such as brewer's spent grain and yeast, were used in TP27 and TP41 diets to ensure equal protein contents to the control diet. Results showed no different for larval and pupal weights between diets; however, the time of development significantly increases in TP100 compared to all diets. The feed conversion rate progressively increases from 2.7 to 4.3, respectively, from the control to the TP100 diet. Conversely, lycopene and β-carotene increase in the larvae. The fatty acid composition improves by increasing polyunsaturated fatty acids (mainly α-linoleic acid). Although the best nutritional quality was obtained in T100, the TP41 is the optimal diet for balance between larval performance and qualitative improvement of larvae. Therefore, tomato pomace is suitable for the formulation of mealworm diets, even in high dosages, when supplemented with sustainable protein and carbohydrate sources.

Carotenoids in Health as Studied by Omics-Related Endpoints

Carotenoids have been associated with risk reduction for several chronic diseases, including the association of their dietary intake/circulating levels with reduced incidence of obesity, type 2 diabetes, certain types of cancer, and even lower total mortality. In addition to some carotenoids constituting vitamin A precursors, they are implicated in potential antioxidant effects and pathways related to inflammation and oxidative stress, including transcription factors such as nuclear factor κB and nuclear factor erythroid 2-related factor 2. Carotenoids and metabolites may also interact with nuclear receptors, mainly retinoic acid receptor/retinoid X receptor and peroxisome proliferator-activated receptors, which play a role in the immune system and cellular differentiation. Therefore, a large number of downstream targets are likely influenced by carotenoids, including but not limited to genes and proteins implicated in oxidative stress and inflammation, antioxidation, and cellular differentiation processes. Furthermore, recent studies also propose an association between carotenoid intake and gut microbiota. While all these endpoints could be individually assessed, a more complete/integrative way to determine a multitude of health-related aspects of carotenoids includes (multi)omics-related techniques, especially transcriptomics, proteomics, lipidomics, and metabolomics, as well as metagenomics, measured in a variety of biospecimens including plasma, urine, stool, white blood cells, or other tissue cellular extracts. In this review, we highlight the use of omics technologies to assess health-related effects of carotenoids in mammalian organisms and models.

Mathematical Modeling of Thin-Layer Drying Kinetics of Tomato Peels: Influence of Drying Temperature on the Energy Requirements and Extracts Quality

Tomato drying implies high energy consumption due to the high moisture content, and limiting drying temperatures is necessary to avoid carotenoid degradation. To explain the mechanism of moisture transport through the material and to scale up the drying process, drying experiments are needed and supported by mathematical modeling. For the Rila tomato peel drying process, ten thin-layer mathematical models were formulated based on experimental data for six temperatures (50-75 °C) and validated by statistical analysis. Considering the slab geometry of the peels sample and Fick's second law of diffusion model, the calculated effective moisture diffusivity coefficient values Deff varied between 1.01 × 10-9-1.53 × 10-9 m2/s with R2 higher than 0.9432. From the semi-theoretical models, Two-term presents the best prediction of moisture ratio with the highest R2 and lowest χ2 and RMSE values. Using the experimental data on extract quality (carotenoid content), two degradation models were formulated. Increasing the drying temperature from 50 °C to 110 °C, a degradation of 94% for lycopene and 83% for β-carotene were predicted. From the energy analysis, a specific energy consumption of 56.60 ± 0.51 kWh is necessary for hot-air drying of 1 kg of Rila tomato peel at 50 °C to avoid carotenoid degradation.

Coproduction of Phase-Separated Carotenoids and β-Farnesene as a Yeast Biomass Valorization Strategy

Valorization, the process whereby waste materials are converted into more valuable products, is rarely practiced in industrial fermentation. We developed a model valorization system whereby Saccharomyces cerevisiae that had previously been engineered to produce high concentrations (>100 g/L) of extracellular β-farnesene was further engineered to simultaneously produce intracellular carotenoids, both products being isoprenoids. Thus, a single fermentation generates two valuable products, namely, β-farnesene in the liquid phase and carotenoids in the solid biomass phase. Initial attempts to produce high levels of canthaxanthin (a ketocarotenoid used extensively in animal feed) in a β-farnesene production strain negatively impacted both biomass growth and β-farnesene production. A refined approach used a promoter titration strategy to reduce β-carotene production to a level that had minimal impact on growth and β-farnesene production in fed-batch fermentations and then engineered the resulting strain to produce canthaxanthin. Further optimization of canthaxanthin coproduction used a bioprospecting approach to identify ketolase enzymes that maximized conversion of β-carotene to canthaxanthin. Finally, we demonstrated that β-carotene is not present in the extracellular β-farnesene at a significant concentration and that which is present can be removed by a simple distillation, indicating that β-farnesene (the primary fermentation product) purity is unaffected by coproduction of carotenoids.

Quantitative and modularized CRISPR/dCas9-dCpf1 dual function system in Saccharomyces cerevisiae

Introduction: Both CRISPR/dCas9 and CRISPR/dCpf1 genome editing systems have shown exciting promises in modulating yeast cell metabolic pathways. However, each system has its deficiencies to overcome. In this study, to achieve a compensatory effect, we successfully constructed a dual functional CRISPR activation/inhibition (CRISPRa/i) system based on Sp-dCas9 and Fn-dCpf1 proteins, along with their corresponding complementary RNAs. Methods: We validated the high orthogonality and precise quantity targeting of selected yeast promoters. Various activating effector proteins (VP64, p65, Rta, and VP64-p65-Rta) and inhibiting effector proteins (KRAB, MeCP2, and KRAB-MeCP2), along with RNA scaffolds of MS2, PP7 and crRNA arrays were implemented in different combinations to investigate quantitative promoter strength. In the CRISPR/dCas9 system, the regulation rate ranged from 81.9% suppression to 627% activation in the mCherry gene reporter system. Studies on crRNA point mutations and crRNA arrays were conducted in the CRISPR/dCpf1 system, with the highest transcriptional inhibitory rate reaching up to 530% higher than the control. Furthermore, the orthogonal CRISPR/dCas9-dCpf1 inhibition system displayed distinct dual functions, simultaneously regulating the mCherry gene by dCas9/gRNA (54.6% efficiency) and eGFP gene by dCpf1/crRNA (62.4% efficiency) without signal crosstalk. Results and discussion: Finally, we established an engineered yeast cell factory for β-carotene production using the CRISPR/dCas9-dCpf1 bifunctional system to achieve targeted modulation of both heterologous and endogenous metabolic pathways in Saccharomyces cerevisiae. The system includes an activation module of CRISPRa/dCas9 corresponding to a gRNA-protein complex library of 136 plasmids, and an inhibition module of CRISPRi/dCpf1 corresponding to a small crRNA array library. Results show that this CRISPR/dCas9-dCpf1 bifunctional orthogonal system is more quantitatively effective and expandable for simultaneous CRISPRa/i network control compared to single-guide edition, demonstrating higher potential of future application in yeast biotechnology.

The Effect of Beta-Carotene on Cognitive Function: A Systematic Review

β-carotene is a powerful antioxidant and dietary precursor of vitamin A whose role in maintaining mental health and cognitive performance, either alone or in combination with other dietary compounds, has been a topic of recent research. However, its effectiveness is still unclear. This systematic review, conducted according to the PRISMA guideline and assisted by the MySLR platform, addressed this issue. A total of 16 eligible original research articles were identified. Dietary intake or β-carotene serum levels were associated with improved measures of cognitive function in 7 out of 10 epidemiological studies included. In intervention studies, β-carotene consumption alone did not promote better cognitive function in the short term, but only in a long-term intervention with a mean duration of 18 years. However, all but one intervention study suggested the beneficial effects of β-carotene supplementation at doses ranging from 6 mg to 50 mg per day in combination with a multicomplex such as vitamin E, vitamin C, zinc, or selenium for a period of 16 weeks to 20 years. Despite the current limitations, the available evidence suggests a potential association between β-carotene dietary/supplementary intake and the maintenance of cognitive function. The β-carotene most probably does not act alone but in synergy with other micronutrients.

Oxidative stability differences of aqueous model systems of photoautotrophic n-3 LC-PUFA rich microalgae: The antioxidative role of endogenous carotenoids

Microalgae rich in omega-3 long-chain polyunsaturated fatty acids (n-3LC-PUFA) have already shown their potential for developing functional food rich in these healthy fatty acids. Not only could they offer a more sustainable alternative for the fish stock that is currently relied upon but is unable to keep up with the demand, enrichment with certain microalgae also leads to oxidatively stable products. Although the reason for this stability has been attributed to the presence of endogenous carotenoids, further insight into their antioxidative role is missing and would be clarifying for selecting the proper microalgae for food enrichment. In trying to further accomplish this, a storage experiment (4 weeks, 37 °C) was set up with the parallel analysis of both oxidation products (primary and secondary) and carotenoids of two aqueous model systems of different (promising) microalgae (Nannochloropsis and Phaeodactylum). The results showed a clear difference in oxidative stability despite both microalgae containing endogenous carotenoids: Nannochloropsis led to oxidatively unstable and Phaeodactylum to oxidatively stable products. This was clearly confirmed by the analysis of n-3LC-PUFA throughout storage which showed a breakdown of half of the n-3LC-PUFA for Nannochloropsis. All carotenoids (violaxanthin, zeaxanthin and β-carotene for Nannochloropsis, and fucoxanthin and β-carotene for Phaeodactylum) acted as an antioxidant as shown by their degradation throughout storage, but the difference in oxidative stability pointed out an impact of carotenoid content and (possibly) type. The presence of a sufficient amount of carotenoids seems to be an important factor for perceiving oxidative stability. Phaeodactylum has shown to be more potent for food enrichment.

Effect of protein oxidation on the emulsion carrier prepared by rice bran protein for improving stability and bioavailability of β-carotene

The emulsion carriers which prepared by rice bran protein (RBP) with different oxidation extents were utilized to deliver β-carotene (BC). The effects of RBP oxidation extent on stability and bioaccessibility of BC in rice bran protein emulsion (RBPE) were investigated by measuring the droplet size, microstructure, digestive stability, cellular antioxidant, and delivery property of BC-RBPE. The results showed that BC-RBPE prepared by moderately oxidized RBP (extracted from rice bran with a storage time of 5 d) presented excellent digestive stability and delivery property during gastrointestinal digestion. The particle size of initial BC-RBPE, BC-RBPE after gastric digestion, and BC-RBPE after intestinal digestion were 509.73, 2149.33, and 997.82 nm, respectively. Compared with free BC suspension, the BC retention after gastric digestion and the BC bioavailability of BC-RBPE prepared by moderately oxidized RBP increased by 23.50% and 27.54%, respectively. In addition, the BC cellular antioxidant activity and BC cellular uptake of BC-RBPE prepared by moderately oxidized RBP were significantly higher than that of free BC-suspension, which increased by 29.63% and 13.84%, respectively. In summary, the study showed that oil-in-water emulsion prepared by moderately oxidized protein is a potential delivery system of BC, which can provide a theoretical basis for improving the utilization of protein by adjusting the extent of protein oxidation.

Mechanism underlying joint loading and controlled release of β-carotene and curcumin by octenylsuccinated Gastrodia elata starch aggregates

This study aimed to fabricate a novel codelivery system to simultaneously load β-carotene and curcumin in a controlled and synergistic manner. We hypothesized that the aggregates of octenylsuccinated Gastrodia elata starch (OSGES) could efficiently load and control the release of β-carotene and curcumin in combination. Mechanisms underlying the self-assembly of OSGES, coloading, and corelease of β-carotene and curcumin by relevant aggregates were studied. The OSGES could form aggregates with a size of 120.2 nm containing hydrophobic domains surrounded by hydrophilic domains. For coloading, the increased solubilities were attributed to favorable interactions between β-carotene and curcumin as well as interactions with octenyl and starch moieties via hydrophobic and hydrogen-bond interactions, respectively. The β-carotene and curcumin molecules occupied the interior and periphery of hydrophobic domains of OSGES aggregates, respectively, and they did not exist in isolation but interacted with each other. The β-carotene and curcumin combination-loaded OSGES aggregates with a size of 310.5 nm presented a more compact structure than β-carotene-only and curcumin-only loaded OSGES aggregates with sizes of 463.5 and 202.9 nm respectively, suggesting that a transition from a loose cluster to a compact cluster was accompanied by coloading. During in vitro digestion, the joint effect of β-carotene and curcumin prolonged their release and increased their bioaccessibility due to competition between favorable hydrophobic and hydrogen-bond interactions and the unfavorable structure erosion and relaxation of the loaded aggregates. Therefore, OSGES aggregates were designed for the codelivery of β-carotene and curcumin, indicating their potential to be applied in functional foods and dietary supplements.

The Oxidative and Color Stability of Beef from Steers Fed Pasture or Concentrate during Retail Display

Beef production in Uruguay is based on pasture (~85%) or concentrate (~15%), resulting in differences in meat quality. The objective of this study was to compare the oxidative stability and color of beef from these two systems during refrigerated retail display. For these purposes, the Semimembranosus muscle was removed from ten Aberdeen Angus steers raised and fed on pasture (130 days prior to slaughter) and from another ten steers fed concentrate (100 days prior to slaughter), sliced. The muscles were placed in a refrigerated showcase for 3, 6, and 9 days. The contents of β-carotene, α-tocopherol, and fatty acids were determined before the meat was placed on display. Lipid and protein oxidation, color, and heme iron content were determined before and during display. The meat from pasture-fed steers had a lower intramuscular fat content (1.78 ± 0.15 vs. 4.52 ± 0.46), lower levels of monounsaturated fatty acids, a lower n-6/n-3 ratio, less lipid and protein oxidation, lower L* and a* values, and higher levels of α-linolenic acid, DHA, total n-3, β-carotene, and α-tocopherol. In conclusion, the meat from pasture-fed steers was more stable during retail display from an oxidative point of view, which may be due to its higher levels of antioxidant compounds such as β-carotene and α-tocopherol and had a healthier fatty acid profile for consumers.

Metabolic Engineering of Yarrowia lipolytica for Zeaxanthin Production

Zeaxanthin is a carotenoid, a dihydroxy derivative of β-carotene. Zeaxanthin has antioxidant, anti-inflammatory, anticancer, and neuroprotective properties. In this study, Yarrowia lipolytica was used as a host for the efficient production of zeaxanthin. The strain Y. lipolytica PO1h was used to construct the following engineered strains for carotenoid production since it produced the highest β-carotene among the Y. lipolytica PO1h- and Y. lipolytica PEX17-HA-derived strains. By regulating the key nodes on the carotenoid pathway through wild and mutant enzyme comparison and successive modular assembly, the β-carotene concentration was improved from 19.9 to 422.0 mg/L. To provide more precursor mevalonate, heterologous genes mvaE and mvaSMT were introduced to increase the production of β-carotene by 27.2% to the yield of 536.8 mg/L. The β-carotene hydroxylase gene crtZ was then transferred, resulting in a yield of zeaxanthin of 326.5 mg/L. The oxidoreductase RFNR1 and CrtZ were then used to further enhance zeaxanthin production, and the yield of zeaxanthin was up to 775.3 mg/L in YPD shake flask.

Antioxidant Capacity of Polar and Non-Polar Extracts of Four African Green Leafy Vegetables and Correlation with Polyphenol and Carotenoid Contents

In sub-Saharan Africa, chronic malnutrition is often associated with intestinal inflammation and oxidative stress. African green leafy vegetables (GLVs), commonly consumed by these populations and rich in bioactive compounds, may improve the antioxidant status. The aim of this study was to measure the antioxidant capacity using complementary assays (DPPH, FRAP, ABTS, ORAC and NO scavenging) in polar and non-polar leaf extracts of four African GLVs, cassava (Manihot esculenta), roselle (Hibiscus sabdariffa), jute mallow (Corchorus olitorius), and amaranth (Amaranthus spp.), with spinach (Spinacia oleracea) chosen as a reference. Their antioxidant capacity was correlated with their total polyphenol (TPC), flavonoid (TFC), condensed tannin, lutein, and β-carotene contents. Identification of phenolic compounds by UHPLC-DAD-MS/MS revealed the presence of three main classes of compound: flavonols, flavones, and hydroxycinnamic acids. Cassava and roselle leaves presented significantly higher TPC and TFC than amaranth, jute mallow, and spinach. They also exhibited the highest antioxidant capacity, even higher than that of spinach, which is known for its important antioxidant effect. The antioxidant capacity was 2 to 18 times higher in polar than non-polar extracts, and was more strongly correlated with TPC and TFC (R > 0.8) than with β-carotene and lutein contents. These findings provide new data especially for cassava and roselle leaves, for which studies are scarce, suggesting an appreciable antioxidant capacity compared with other leafy vegetables.