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.

Jeongeuplla avenae gen. nov., sp. 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.