Review of methods for analysis of carotenoids

Recent Advances in Efficient Lutein-Loaded Zein-Based Solid Nano-Delivery Systems: Establishment, Structural Characterization, and Functional Properties

Plant proteins have gained significant attention over animal proteins due to their low carbon footprint, balanced nutrition, and high sustainability. These attributes make plant protein nanocarriers promising for applications in drug delivery, nutraceuticals, functional foods, and other areas. Zein, a major by-product of corn starch processing, is inexpensive and widely available. Its unique self-assembly characteristics have led to its extensive use in various food and drug systems. Zein's functional tunability allows for excellent performance in loading and transporting bioactive substances. Lutein offers numerous bioactive functions, such as antioxidant and vision protection, but suffers from poor chemical stability and low bioavailability. Nano-embedding technology can construct various zein-loaded lutein nanodelivery systems to address these issues. This review provides an overview of recent advances in the construction of zein-loaded lutein nanosystems. It discusses the fundamental properties of these systems; systematically introduces preparation techniques, structural characterization, and functional properties; and analyzes and predicts the target-controlled release and bioaccessibility of zein-loaded lutein nanosystems. The interactions and synergistic effects between Zein and lutein in the nanocomplexes are examined to elucidate the formation mechanism and conformational relationship of zein-lutein nanoparticles. The physical and chemical properties of Zein are closely related to the molecular structure. Zein and its modified products can encapsulate and protect lutein through various methods, creating more stable and efficient zein-loaded lutein nanosystems. Additionally, embedding lutein in Zein and its derivatives enhances lutein's digestive stability, solubility, antioxidant properties, and overall bioavailability.

Novel tributyl phosphate-based deep eutectic solvent: Application in microwave assisted extraction of carotenoids

A contribution to the use of deep eutectic solvents (DES) and microwave-assisted extraction (MAE) was made for bioactive compounds recovery, especially those with lipophilic character, from tomato and carrot samples rich in carotenoids. For the first time, a novel deep eutectic solvent was synthesized, comprising tributyl phosphate (TBP) as a hydrogen bond acceptor and acetic acid (AcOH) as a hydrogen bond donor. The total antioxidant capacity (TAC) of tomato and carrot extracts obtained by MAE, in which optimization of operational parameters and modeling were made with the use of Box-Behnken design of the response surface methodology (RSM), was evaluated using the Cupric Reducing Antioxidant Capacity (CUPRAC) method. For the highest TAC, operational parameters that best suit the MAE procedure were set at 80 °C, 35 min, and 25 mL/2.0 g. The TAC values of extracts obtained by MAE using TBP:AcOH, 1:2 (mol/mol) were examined against those of extracts acquired by classical solvent extraction using a mixture of hexane, ethanol and acetone (H:E:A, 2:1:1 (v/v/v)) mixture. TAC of extracts in DES varied between 5.10 and 0.71 lycopene equivalents (mmol LYC kg-1). The highest extraction yield comparable to conventional organic solvents was obtained with TBP:AcOH (1:2). It was observed that, in addition to lipophilic antioxidants, some hydrophilic antioxidant compounds were partially extracted with the proposed DES. Moreover, the extracted antioxidant compounds were identified and quantified by HPLC analysis. The proposed DES and MAE process will find potential application for hydrophobic antioxidant extraction from tomatoes and carrots on an industrial scale after further studies.

Astaxanthin Esters as Functional Food: A Review of Their Nutrition, Phytochemical Structure, Biological Features, and Food Industry Prospects

Astaxanthin (AST), mainly found in algae and shrimp, is a liposoluble ketone carotenoid with a wide range of biological activities and is commonly used in healthcare interventions and cosmetics. AST has a long chain of conjugated double bonds with hydroxyl and ketone groups at both ends, enabling it to form astaxanthin esters (AST-Es) through esterification with fatty acids. The fatty acid structure of AST plays a key role in the stability, antioxidant activity, and bioavailability of AST-Es. Antarctic krill (Euphausia superba) and blood-red algae Haematococcus Pluvialis (H pluvialis)-derived AST-Es exhibit strong antioxidant activity and numerous biological activities, such as improving insulin resistance, preventing Parkinson's disease, regulating intestinal flora, and alleviating inflammatory bowel disease. This review discusses the significance of AST-Es as functional food ingredients, highlighting their nutritional value, phytochemical structure, biological activities, and potential applications in the food industry.

Clpf encodes pentatricopeptide repeat protein (PPR5) and regulates pink flesh color in watermelon (Citrullus lanatus L.)

KEY MESSAGE

The gene controlling pink flesh in watermelon was finely mapped to a 55.26-kb region on chromosome 6. The prime candidate gene, Cla97C06G122120 (ClPPR5), was identified through forward genetics. Carotenoids offer numerous health benefits; while, they cannot be synthesized by the human body. Watermelon stands out as one of the richest sources of carotenoids. In this study, genetic generations derived from parental lines W15-059 (red flesh) and JQ13-3 (pink flesh) revealed the presence of the recessive gene Clpf responsible for the pink flesh (pf) trait in watermelon. Comparative analysis of pigment components and microstructure indicated that the disparity in flesh color between the parental lines primarily stemmed from variations in lycopene content, as well as differences in chromoplast number and size. Subsequent bulk segregant analysis (BSA-seq) and genetic mapping successfully narrowed down the Clpf locus to a 55.26-kb region on chromosome 6, harboring two candidate genes. Through sequence comparison and gene expression analysis, Cla97C06G122120 (annotated as a pentatricopeptide repeat, PPR) was predicted as the prime candidate gene related to pink flesh trait. To further investigate the role of the PPR gene, its homologous gene in tomato was silenced using a virus-induced system. The resulting silenced fruit lines displayed diminished carotenoid accumulation compared with the wild-type, indicating the potential regulatory function of the PPR gene in pigment accumulation. This study significantly contributes to our understanding of the forward genetics underlying watermelon flesh traits, particularly in relation to carotenoid accumulation. The findings lay essential groundwork for elucidating mechanisms governing pigment synthesis and deposition in watermelon flesh, thereby providing valuable insights for future breeding strategies aimed at enhancing fruit quality and nutritional value.

Sources of Carotenoids in Amazonian Fruits

Epidemiological studies have shown that a diet rich in bioactive components significantly reduces cardiovascular disease incidence and mortality. In this sense, there is a need for meta-analytical research that confirms this phenomenon and increases specific knowledge about certain bioactive compounds such as carotenoids. Thus, this systematic review and meta-analysis aim to disseminate knowledge about the sources of carotenoids in fruit consumed in the north of Brazil which are outside the Brazilian trade balance. A systematic review and a meta-analysis following the PRISMA guidelines were conducted based on a random effects synthesis of multivariable-adjusted relative risks (RRs). Searches of seven sources were carried out, including PubMed, Science Direct from Elsevier, Web of Science, Scielo, Eric Research and Google Scholar databases. The systematic review was guided by a systematic review protocol based on the POT strategy (population, outcome and type of study) adapted for use in this research. Mendeley was a resource used to organize and manage references and exclude duplicates of studies selected for review. In this review, we present the potential bioactive compounds concentrated in little-known fruit species from the Amazon and their benefits. Consuming fruits that are rich in notable constituents such as carotenoids is important for the prevention of chronic non-communicable diseases through anti-inflammatory and anticoagulant properties, as well as antivirals, immunomodulators and antioxidants agents that directly affect the immune response.

Transgenic black soldier flies for production of carotenoids

The black soldier fly (BSF), Hermetia illucens, has gained traction recently as a means to achieve closed-loop production cycles. BSF can subsist off mammalian waste products and their consumption of such waste in turn generates compost that can be used in agricultural operations. Their environmental impact is minimal and BSF larvae are edible, with a nutritional profile high in protein and other essential vitamins. Therefore, it is conceivable to use BSF as a mechanism for both reducing organic waste and maintaining a low-impact food source for animal livestock or humans. The main drawback to BSF as a potential human food source is they are deficient in fat-soluble vitamins such as Vitamins A, D, and E. While loading BSF with essential vitamins may be achieved via diet-based interventions, this undercuts the goal of a closed-loop as specialized diets would require additional supply chains. An alternative is to genetically engineer BSF that can synthesize these essential vitamins. Here we describe a BSF line that has been engineered with the two main carotenoid biosynthetic genes, CarRA and CarB for production of provitamin carotenoids within the Vitamin A family. Our data describe the manipulation of the BSF genome to insert transgenes for expression of functional protein products.

Color components determination and full-length comparative transcriptomic analyses reveal the potential mechanism of carotenoid synthesis during Paphiopedilum armeniacum flowering

Background

Paphiopedilum armeniacum (P. armeniacum), an ornamental plant native to China, is known for its distinctive yellow blossoms. However, the mechanisms underlying P. armeniacum flower coloration remain unclear.

Methods

We selected P. armeniacum samples from different flowering stages and conducted rigorous physicochemical analyses. The specimens were differentiated based on their chemical properties, specifically their solubilities in polar solvents. This key step enabled us to identify the main metabolite of flower color development of P. armeniacum, and to complete the identification by High-performance liquid chromatography (HPLC) based on the results. Additionally, we employed a combined approach, integrating both third-generation full-length transcriptome sequencing and second-generation high-throughput transcriptome sequencing, to comprehensively explore the molecular components involved.

Results

We combined physical and chemical analysis with transcriptome sequencing to reveal that carotenoid is the main pigment of P. armeniacum flower color. Extraction colorimetric method and HPLC were used to explore the characteristics of carotenoid accumulation during flowering. We identified 28 differentially expressed carotenoid biosynthesis genes throughout the flowering process, validated their expression through fluorescence quantification, and discovered 19 potential positive regulators involved in carotenoid synthesis. Among these candidates, three RCP2 genes showed a strong potential for governing the PDS and ZDS gene families. In summary, our study elucidates the fundamental mechanisms governing carotenoid synthesis during P. armeniacum flowering, enhancing our understanding of this process and providing a foundation for future research on the molecular mechanisms driving P. armeniacum flowering.

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.

Carotenoids and Tocopherol Profiling in Fleshy Fruits

Carotenoids and tocopherols are among the most powerful lipophilic antioxidants accumulated in fruit and vegetable crops. This chapter describes a method for the separation and quantification of carotenoids/chlorophylls and tocopherols based on microextraction followed by reverse- and normal-phase HPLC, respectively. Using this method, high-throughput, accurate analysis of these compounds can be performed in leaf and fruit samples.

Trends and advances in pre- and post-harvest processing of linseed oil for quality food and health products

Linseed is an ancient crop used for diverse purposes since the beginning of civilization. In recent times, linseed has emerged as a superfood due to its high content of health-promoting omega-3 fatty acids and other bioactive compounds. Among primary health effects, it has potential to manage hypertension, diabetes, osteoporosis, atherosclerosis, cancer, arthritis, neurological, cardiovascular diseases including blood cholesterol levels, constipation, diarrhea, and autoimmune disorders etc. due to the presence of omega-3 fatty acid, lignans, high dietary fibers, and proteins, whereas, secondary health effects comprise of relieving from various skin disorders. Due to these health-beneficial properties, interest in linseed oil necessitates the intensification of research efforts on various aspects. These include cultivation technology, varietal and genetic improvement, post-harvest processing, profiling of nutrients and bioactive compounds, pre-clinical and clinical studies, etc. The present review discussed the advances in linseed research including pre- and post-harvest processing. However, focus on the bioactive compounds present in linseed oil and their health effects are also presented. Linseed cultivation, pre- and post-harvest processing aspects are covered including climatic, edaphic, agronomic factors, type of cultivar and storage conditions etc, which impact the overall oil yield and its nutritional quality. Various emerging applications of linseed oil in functional food, nutraceutical, pharmaceutical, and cosmeceutical preparations were also presented in detail. Further, recommendations were made on linseed oil research in the field of genetics, breeding germplasm resources and genome editing for exploring its full applications as a nutrition and health product.

Development and application of a SFC-DAD-MS/MS method to determine carotenoids and vitamin A in egg yolks from laying hens supplemented with β-carotene

β-Carotene, a provitamin A carotenoid, can be converted into vitamin A in animals' bodies, and can also be accumulated intactly in many animal products. In this study, supercritical fluid chromatography-tandem mass spectrometry was utilized to determine β-carotene and different forms of vitamin A in eggs simultaneously. According to the results, β-carotene contained in yolk reached a plateau after about 2 weeks of supplementation. With an increase in dietary supplement level, the amount of β-carotene gradually increased, as well as slightly changing the yolk color. Moreover, the contents of retinoids including retinol, retinyl propionate, retinyl palmitate and retinyl stearate were also elevated in yolks with the β-carotene additive levels; meanwhile, the lutein and zeaxanthin decreased. On the whole, β-carotene in the diet of laying hens could be partially deposited in egg yolk, and the contents of vitamin A in yolk could be increased due to β-carotene bioconversion.

Lycopene in Feed as Antioxidant and Immuno-Modulator Improves Broiler Chicken's Performance under Heat-Stress Conditions

Lycopene is a type of carotenoid pigment widely distributed in various plants and fruits, with tomatoes, carrots, and guava being the most abundant sources. Due to its high content of beneficial active components, lycopene has been used in medicine, where it is employed as a dietary additive for cancer therapy, immune modulator, and feed additive to improve livestock productivity. Lycopene is a lipophilic substance that can act as either a prooxidant or a free radical scavenger and is particularly efficient in enhancing broiler performance. Furthermore, lycopene can alleviate heat stress by improving the activity of various antioxidant enzymes such as superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT), as well as increasing the total antioxidant capacity (T-AOC) and nuclear muscle factor erythroid 2-related factor 2 (Nrf2), while simultaneously reducing the levels of malondialdehyde (MDA) and muscle Keap1 expression. In addition, lycopene can improve broiler fertility by enhancing sperm performance and reducing inflammation by modulating the levels of interleukin 1, 2, and 10 (IL-1, IL-2, and IL-10) in cases of infection. In cases of disease by aflatoxin B1 (AFB1), lycopene can modulate interferon-γ (IFN-γ), IL-1, claudin-1 (CLDN-1), and zonula occludens-1 (ZO-1). Furthermore, under the lipopolysaccharide challenge, lycopene can increase the relative weights of immune organ indices such as the bursal, spleen, and thymus.

Carotenoids Diet: Digestion, Gut Microbiota Modulation, and Inflammatory Diseases

Several epidemiologic studies have found that consuming fruits and vegetables lowers the risk of getting a variety of chronic illnesses, including several types of cancers, cardiovascular diseases (CVDs), and bowel diseases. Although there is still debate over the bioactive components, various secondary plant metabolites have been linked to these positive health benefits. Many of these features have recently been connected to carotenoids and their metabolites' effects on intracellular signalling cascades, which influence gene expression and protein translation. Carotenoids are the most prevalent lipid-soluble phytochemicals in the human diet, are found in micromolar amounts in human serum, and are very susceptible to multiple oxidation and isomerisation reactions. The gastrointestinal delivery system, digestion processes, stability, and functionality of carotenoids, as well as their impact on the gut microbiota and how carotenoids may be effective modulators of oxidative stress and inflammatory pathways, are still lacking research advances. Although several pathways involved in carotenoids' bioactivity have been identified, future studies should focus on the carotenoids' relationships, related metabolites, and their effects on transcription factors and metabolism.

Natural Carotenoids: Recent Advances on Separation from Microbial Biomass and Methods of Analysis

Biotechnologically produced carotenoids occupy an important place in the scientific research. Owing to their role as natural pigments and their high antioxidant properties, microbial carotenoids have been proposed as alternatives to their synthetic counterparts. To this end, many studies are focusing on their efficient and sustainable production from renewable substrates. Besides the development of an efficient upstream process, their separation and purification as well as their analysis from the microbial biomass confers another important aspect. Currently, the use of organic solvents constitutes the main extraction process; however, environmental concerns along with potential toxicity towards human health necessitate the employment of "greener" techniques. Hence, many research groups are focusing on applying emerging technologies such as ultrasounds, microwaves, ionic liquids or eutectic solvents for the separation of carotenoids from microbial cells. This review aims to summarize the progress on both the biotechnological production of carotenoids and the methods for their effective extraction. In the framework of circular economy and sustainability, the focus is given on green recovery methods targeting high-value applications such as novel functional foods and pharmaceuticals. Finally, methods for carotenoids identification and quantification are also discussed in order to create a roadmap for successful carotenoids analysis.

Effect of ultrasonic pretreatment on tocochromanol and carotenoid biofortification in maize (Zea mays L.) seedlings

BACKGROUND

Maize is a sought-after food crop because it is micronutrient-rich and affordable. It is an excellent source of carotenoids and tocochromanols. To investigate ways to enhance the micronutrients in maize, we grew maize seedlings with ultrasonic pretreatment to study the effect of ultrasound pretreatment on the biofortification of tocochromanols and carotenoids using high-performance liquid chromatography and real-time quantitative polymerase chain reaction.

RESULTS

Four tocopherol isomers, three tocotrienol isomers and six carotenoid components were measured in maize seedlings. Compared with the untreated maize seedlings, carotenoid content increased and reached the highest level at 8 min ultrasonic pretreatment (19.21 ± 0.44 μg g^-1 fresh weight (FW)), but tocotrienol content evidently decreased. Tocopherol dropped at first but began to rise after 8 min ultrasonic pretreatment (258.1 ± 6.4 μg g^-1 FW). In particular, zeaxanthin in maize seedlings doubled after pre-sonication, while lutein was boosted to 11.81 ± 0.20 μg g^-1 FW. Ultrasonic pretreatment changed the predominant component of tocochromanols in maize seedlings from γ-tocotrienol to α-tocopherol, with the latter content being 1.3 times higher than in the untreated group. Up-regulation of key genes involved in the biosynthesis of tocopherols and carotenoids in maize seedlings occurred as a result of both 2 min and 6 min sonication pretreatment. In particular, _Zm HPPD, _Zm ZE, _Zm ZDS and _Zm MPBQ-MT could partly explain the changes in these phytochemicals.

CONCLUSION

Wet ultrasonic pretreatment could increase tocopherol and carotenoid accumulation in maize seedlings but decrease tocotrienol synthesis. Some up-regulating genes are related to relevant syntheses, such as _Zm HPPD, _Zm ZE, _Zm ZDS and _Zm MPBQ-MT, which could influence the accumulation of tocopherols and carotenoids after ultrasonic pretreatment. © 2022 Society of Chemical Industry.

Freeze-Dried Powder of Fermented Chili Paste-New Approach to Cured Salami Production

Fermented chili powders were obtained through the freeze-drying of fermented chili pastes and used as a condiment, acidifier, antioxidant, colorant, and microbial starter carrier in fermented salami production. Fermented chili powders were examined regarding carbohydrates, organic acids, vitamin C, phenolic compounds, carotenoids, and aroma profile. High concentrations of lactic (10.57-12.20%) and acetic acids (3.39-4.10%) were recorded. Vitamin C content was identified in the range of 398-1107 mg/100 g, with maximum values for C. annuum cv. Cayenne chili powder. Phenolic compounds showed values between 302-771 mg/100 g. Total carotenoid content was identified between 544-2462 µg/g, with high concentrations of capsanthin esters. Aroma profile analysis evidenced specific compounds (1-hexanol, 2-hexanol, hexenal, E-2-hexenal) with sensory importance and a more complex spectrum for Capsicum chinense cultivar. Plant-specific lactic acid bacteria showed dominance both in fermented chili paste, chili powder, and salami. Lactic and acetic acids from the fermented chili powder reduced the pH of the filling immediately, having a stabilizing effect on the meat. Nor molds or pathogens were identified in outer limits. Based on these results, fermented chili powders could be used as starter carriers in the production of fermented meat products for exceptional sensory properties and food safety management.

The Role of Equilibrium between Free Radicals and Antioxidants in Depression and Bipolar Disorder

Background: Increasing evidence suggests that the presence of oxidative stress and disorders of the antioxidant defense system are involved in a wide range of neuropsychiatric disorders, such as bipolar disorder, schizophrenia and major depression, but the exact mechanism remains unknown. This review focuses on a better appreciation of the contribution of oxidative stress to depression and bipolar disorder. Methods: This review was conducted by extracting information from other research and review studies, as well as other meta-analyses, using two search engines, PubMed and Google Scholar. Results: As far as depression is concerned, there is agreement among researchers on the association between oxidative stress and antioxidants. In bipolar disorder, however, most of them observe strong lipid peroxidation in patients, while regarding antioxidant levels, opinions are divided. Nevertheless, in recent years, it seems that on depression, there are mainly meta-analyses and reviews, rather than research studies, unlike on bipolar disorder. Conclusions: Undoubtedly, this review shows that there is an association among oxidative stress, free radicals and antioxidants in both mental disorders, but further research should be performed on the exact role of oxidative stress in the pathophysiology of these diseases.

Characterization of carotenoids in Lycium barbarum fruit by using UPC2-PDA-Q-TOF-MSE couple with deep eutectic solvents extraction and evaluation of their 5α-reductase inhibitory activity

Carotenoids from Lycium barbarum fruits have possessed pharmacological efficacy against eye diseases, cardiovascular disorders, cancer, and benign prostatic hyperplasia. However, the efficient extraction, rapid characterization and activities evaluation of Lycium carotenoids remains a challenge. To concentrate and characterize Lycium carotenoids, we have developed ultrasound-assisted extraction methods with different deep eutectic solvents (DESs) and analyzed carotenoids by ultra-performance convergence chromatography coupled with photo diode array detector and quadrupole time-of-flight mass spectrometry (UPC²-PDA-Q-TOF-MS^E). DESs containing choline chloride and malonic acid presented better extraction efficiency and were more environmentally friendly than other extraction methods. Carotenoids were more quickly profiled (in 11 min) by UPC² compared to by UPLC (in 35 min), with seventeen main peaks were characterized in the MS fragmentation patterns. The in vitro 5α-reductase inhibitory activity of DESs extracts, fractions and components were subsequently assessed, and the predominant component zeaxanthin dipalmitate (ZD) exhibited potent inhibitory activity. Our study provides a chemical and pharmacological basis for the further development of potential new drugs based on Lycium carotenoids.

Optimization and multiple in vitro activity potentials of carotenoids from marine Kocuria sp. RAM1

Marine pigmented bacteria are a promising natural source of carotenoids. Kocuria sp. RAM1 was isolated from the Red Sea Bohadschia graeffei collected from Marsa Alam, Egypt, and used for carotenoids production. The extracted carotenoids were purified by thin-layer chromatography (TLC). The characteristic UV absorbance of the three purified fractions gave us an inkling of what the purified pigments were. The chemical structures were confirmed by nuclear magnetic resonance spectroscopy (NMR) and LC-ESI-QTOF-MS/MS. The three different red pigments were identified as two C₅₀-carotenoids, namely bisanhydrobacterioruberin and trisanhydrobacterioruberin, in addition to 3,4,3',4'-Tetrahydrospirilloxanthin (C₄₂-carotenoids). Kocuria sp. RAM1 carotenoids were investigated for multiple activities, including antimicrobial, anti-inflammatory, antioxidant, anti-HSV-1, anticancer, antidiabetic and wound healing. These new observations suggest that Kocuria sp. RAM1 carotenoids can be used as a distinctive natural pigment with potent properties.

Advances in the synthesis of three typical tetraterpenoids including β-carotene, lycopene and astaxanthin

Carotenoids are natural pigments that widely exist in nature. Due to their excellent antioxidant, anticancer and anti-inflammatory properties, carotenoids are commonly used in food, medicine, cosmetic and other fields. At present, natural carotenoids are mainly extracted from plants, algae and microorganisms. With the rapid development of metabolic engineering and molecular biology as well as the continuous in-depth study of carotenoids synthesis pathways, industrial microorganisms have showed promising applications in the synthesis of carotenoids. In this review, we introduced the properties of several carotenoids and their biosynthetic metabolism process. Then, the microorganisms synthesizing carotenoids through the natural and non-natural pathways and the extraction methods of carotenoids were summarized and compared. Meanwhile, the influence of substrates on the carotenoids production was also listed. The methods and strategies for achieving high carotenoid production are categorized to help with future research.

Fatty acid profile, secondary compounds and antioxidant activities in the fresh forage, hay and silage of sainfoin (Onobrychis viciifolia) and sulla (Hedysarum coronarium)

BACKGROUND

Sainfoin (Onobrychis viciifolia) and sulla (Hedysarum coronarium) are forage legumes usually preserved to optimize their utilization as feedstuffs. However, the method of preservation modifies the chemical composition differently in both legume species. Secondary compounds (such as proanthocyanidins, fatty acids, carotenoids and tocopherols) present in forages affect the quality of animal products. Therefore, the effect of preservation on the contents of secondary compounds should be investigated. Accoridngly, samples of sainfoin and sulla were directly freeze-dried (fresh), dried at ambient temperature (hay) and vacuum-packaged for 82 days (silage).

RESULTS

In both legumes, the total fatty acid and C18:3 n-3 contents decreased and C16:0 increased with preservation (P < 0.001), with a greater effect for the hays than for the silages. For both legumes, the lutein, neoxanthin and violaxanthin contents decreased to a greater extent in the silages than in the hays (P < 0.001). Both hays exhibited the lowest β-carotene concentrations (P < 0.001). The α-tocopherol contents decreased in hays, but not in silages, compared to the fresh forages of both legumes (P < 0.001). The antioxidant activities were lower in the silages than in the hays and fresh forages (P < 0.001) and were very strongly related to the contents of polyphenols and proanthocyanidins (P < 0.001).

CONCLUSION

Haymaking affected the fatty acid, carotenoid and α-tocopherol contents to a greater extent but had a lesser effect on the antioxidant activities than silage-making, which were very strongly related to their contents of polyphenols and proanthocyanidins. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Carotenoid content and composition: A special focus on commercially important fish and shellfish

Carotenoids are natural pigments that provide many health benefits to living organisms. Although terrestrial plants are the major dietary source of carotenoids for humans, aquatic animals (especially fish and shellfish) are equally important because they are rich in certain important carotenoids lacking in fruits and vegetables. Although extensive research has focused on exploring the carotenoid content and composition in fish and shellfish, this information is poorly organized. This paper reviews the scientific evidence for the carotenoid content and composition in fish and shellfish. It makes serious attempts to summarize the relevant data published on specific research questions in order to improve the understanding of various evidence to clarify the research status of carotenoids in fish and shellfish and defining topics for future studies. From the analysis of published data, it is obvious that most fish and shellfish are rich in complex carotenoids (e.g. astaxanthin, fucoxanthin, fucoxanthinol, lutein). These carotenoids have stronger antioxidant effect, higher efficiency in removing the singlet oxygen and the peroxyl radicals, and have a variety of health benefits. Carotenoid levels in fish and shellfish depend on genotype, climatic conditions of the production area, storage and cooking methods. However, the information of the bioavailability of fish/shellfish carotenoids to human is very limited, which hinders the actual contributions to health. The findings of this study can be used as a guide to select appropriate fish and shellfish as dietary sources of carotenoids, and provide information about potential fish and shellfish species for aquaculture to produce carotenoids to meet part of the growing demand for natural carotenoids.

MALDI-TOF MS: application in diagnosis, dereplication, biomolecule profiling and microbial ecology

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has revolutionized scientific research over the past few decades and has provided a unique platform in ongoing technological developments. Undoubtedly, there has been a bloom chiefly in the field of biological sciences with this emerging technology, and has enabled researchers to generate critical data in the field of disease diagnoses, drug development, dereplication. It has received well acceptance in the field of microbial identification even at strain level, as well as diversified field like biomolecule profiling (proteomics and lipidomics) has evolved tremendously. Additionally, this approach has received a lot more attention over conventional technologies due to its high throughput, speed, and cost effectiveness. This review aims to provide a detailed insight regarding the application of MALDI-TOF MS in the context of medicine, biomolecule profiling, dereplication, and microbial ecology. In general, the expansion in the application of this technology and new advancements it has made in the field of science and technology has been highlighted.

An efficient process for the extraction of lutein and chemical characterization of other organic volatiles from marigold (Tagetes erecta L.) flower

Marigold (Tagetes erecta L.) petals are the primary industrial source of lutein, which is used as a colouring agent and nutrient supplement to foods. This research extracted marigold petals using different solvents, covering conventional and non-toxic green solvents. The oleoresin, free lutein, and recrystallized lutein yields varied from 8.47-16.67%, 2.56-9.62%, and 1.11-1.61%, respectively. The purity of lutein was achieved up to 92.57% and 97.64% in conventional and newly established green methods, respectively. The present study described an efficient green process to isolate lutein with significantly improved yield (2.56%) and purity (97.33%) over the conventional methods. Based on the results, 2-methyltetrahydrofurancould be a practical green alternative to the traditional toxic solvents for the processing of lutein. Further, the chemical analysis of the essential oil of the residual receptacles obtained after removing petals revealed the presence of important organic volatiles, including piperitone (54.7%) and piperitenone oxide (6.5%), indicating its usefulness for value-addition.

Swellable Sorbent Coatings for Parallel Extraction, Storage, and Analysis of Plant Metabolites

Quantitative and qualitative measurements of trace-level analytes in plants or foodstuffs, e.g., secondary metabolites like carotenoids, are often performed at centralized core facilities or off-site laboratories. However, preparation, storage, and/or transport of both intact samples and sample extracts may be cumbersome and complicated, especially for air-sensitive analytes. We describe the development of inexpensive swellable microextraction (SweME) devices for extraction and storage of nonpolar analytes. SweME devices consist of a thin layer of poly(dimethylsiloxane) (PDMS) grafted onto a stainless steel support. Pretreating the SweME device with small volumes of the organic solvent causes the PDMS to swell. The swollen SweME device can then be immersed directly into complex matrices for absorptive extraction of low-molecular-weight, nonpolar analytes. Following storage, analytes can be solvent-desorbed prior to characterization. Proof-of-principle work with carotenoids from tomatoes and carrots demonstrates that SweME is appropriate for semiquantitative analyses and increases the stability of air-sensitive analytes during storage at ambient temperatures as compared to the solvent extracts. Carotenoid profiles (fractional carotenoid contributions) from tomato and carrot samples were well correlated between SweME and liquid-liquid extraction (R² = 0.97 and 0.94). Lycopene, the most abundant carotenoid in tomatoes, saw a less than 20% decrease in extracted mass during 1 month of ambient SweME storage. Extractions and desorptions can be run in parallel using multiwell plates. In summary, swelled sorbent extraction with SweME devices is a convenient and inexpensive approach for isolation and storage of analytes in complex matrices and may be particularly well suited for evaluating large numbers of plant samples through external laboratories.

Marine Microbial-Derived Resource Exploration: Uncovering the Hidden Potential of Marine Carotenoids

Microbes in marine ecosystems are known to produce secondary metabolites. One of which are carotenoids, which have numerous industrial applications, hence their demand will continue to grow. This review highlights the recent research on natural carotenoids produced by marine microorganisms. We discuss the most recent screening approaches for discovering carotenoids, using in vitro methods such as culture-dependent and culture-independent screening, as well as in silico methods, using secondary metabolite Biosynthetic Gene Clusters (smBGCs), which involves the use of various rule-based and machine-learning-based bioinformatics tools. Following that, various carotenoids are addressed, along with their biological activities and metabolic processes involved in carotenoids biosynthesis. Finally, we cover the application of carotenoids in health and pharmaceutical industries, current carotenoids production system, and potential use of synthetic biology in carotenoids production.

Rapid Purification of Fucoxanthin from Phaeodactylum tricornutum

Fucoxanthin is a natural marine xanthophyll and exhibits a broad range of biological activities. In the present study, a simple and efficient two-step method was used to purify fucoxanthin from the diatom, Phaeodactylum tricornutum. The crude pigment extract of fucoxanthin was separated by silica gel column chromatography (SGCC). Then, the fucoxanthin-rich fraction was purified using a hydrophile-lipophile balance (HLB) solid-phase extraction column. The identification and quantification of fucoxanthin were determined by high-performance liquid chromatography (HPLC) and electrospray ionization mass spectrometry (ESI-MS). This two-step method can obtain 92.03% pure fucoxanthin and a 76.67% recovery rate. In addition, ¹H and ¹³C NMR spectrums were adopted to confirm the identity of fucoxanthin. Finally, the purified fucoxanthin exhibited strong antioxidant properties in vitro with the effective concentration for 50% of maximal scavenging (EC50) of 1,1-Dihpenyl-2-picrylhydrazyl (DPPH) and 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) free radicals being 0.14 mg·mL^-1 and 0.05 mg·mL^-1, respectively.

Structure and biosynthesis of carotenoids produced by a novel Planococcus sp. isolated from South Africa

Background

The genus Planococcus is comprised of halophilic bacteria generally reported for the production of carotenoid pigments and biosurfactants. In previous work, we showed that the culturing of the orange-pigmented Planococcus sp. CP5-4 isolate increased the evaporation rate of industrial wastewater brine effluent, which we attributed to the orange pigment. This demonstrated the potential application of this bacterium for industrial brine effluent management in evaporation ponds for inland desalination plants. Here we identified a C₃₀-carotenoid biosynthetic gene cluster responsible for pigment biosynthesis in Planococcus sp. CP5-4 through isolation of mutants and genome sequencing. We further compare the core genes of the carotenoid biosynthetic gene clusters identified from different Planococcus species’ genomes which grouped into gene cluster families containing BGCs linked to different carotenoid product chemotypes. Lastly, LC–MS analysis of saponified and unsaponified pigment extracts obtained from cultures of Planococcus sp. CP5-4, revealed the structure of the main (predominant) glucosylated C₃₀-carotenoid fatty acid ester produced by Planococcus sp. CP5-4.

Results

Genome sequence comparisons of isolated mutant strains of Planococcus sp. CP5-4 showed deletions of 146 Kb and 3 Kb for the non-pigmented and “yellow” mutants respectively. Eight candidate genes, likely responsible for C₃₀-carotenoid biosynthesis, were identified on the wild-type genome region corresponding to the deleted segment in the non-pigmented mutant. Six of the eight candidate genes formed a biosynthetic gene cluster. A truncation of crtP was responsible for the “yellow” mutant phenotype. Genome annotation revealed that the genes encoded 4,4′-diapolycopene oxygenase (CrtNb), 4,4′- diapolycopen-4-al dehydrogenase (CrtNc), 4,4′-diapophytoene desaturase (CrtN), 4,4′- diaponeurosporene oxygenase (CrtP), glycerol acyltransferase (Agpat), family 2 glucosyl transferase 2 (Gtf2), phytoene/squalene synthase (CrtM), and cytochrome P450 hydroxylase enzymes. Carotenoid analysis showed that a glucosylated C₃₀-carotenoid fatty acid ester, methyl 5-(6-C_17:3)-glucosyl-5, 6′-dihydro-apo-4, 4′-lycopenoate was the main carotenoid compound produced by Planococcus sp. CP5-4.

Conclusion

We identified and characterized the carotenoid biosynthetic gene cluster and the C₃₀-carotenoid compound produced by Planococcus sp. CP5-4. Mass-spectrometry guided analysis of the saponified and unsaponified pigment extracts showed that methyl 5-glucosyl-5, 6-dihydro-apo-4, 4′-lycopenoate esterified to heptadecatrienoic acid (C_17:3). Furthermore, through phylogenetic analysis of the core carotenoid BGCs of Planococcus species we show that various C₃₀-carotenoid product chemotypes, apart from methyl 5-glucosyl-5, 6-dihydro-apo-4, 4′-lycopenoate and 5-glucosyl-4, 4-diaponeurosporen-4′-ol-4-oic acid, may be produced that could offer opportunities for a variety of applications.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12934-022-01752-1.

Mapping of CaPP2C35 involved in the formation of light-green immature pepper (Capsicum annuum L.) fruits via GWAS and BSA

Genome-wide association study, bulked segregant analysis, and genetic analysis delimited the LG locus controlling light-green immature pepper fruits into a 35.07 kbp region on chromosome 10. A strong candidate gene, CaPP2C35, was identified in this region. In pepper (Capsicum annuum L.), the common colors of immature fruits are yellowish white, milky yellow, green, purple, and purplish black. Genes related to dark green, white, and purple immature fruits have been cloned; however, only a few studies have investigated light-green immature fruits. Here, we performed a genetic study using light-green (17C827) and green (17C658) immature fruits. The light-green color of immature fruits was controlled by a single locus-dominant genetic trait compared with the green color of immature fruits. We also performed a genome-wide association study and bulked segregant analysis of immature-fruit color and mapped the LG locus to a 35.07 kbp region on chromosome 10. Only one gene, Capana10g001710, was found in this region. A G-A substitution occurred at the 313th base of the Capana10g001710 coding sequence in 17C827, resulting in the conversion of the α-helix of its encoded PP2C35 protein into a β-fold. The expression of Capana10g001710 (termed CaPP2C35) in 17C827 was significantly higher than in 17C658. Silencing CaPP2C35 in 17C827 resulted in an increase in chlorophyll content in the exocarp and the appearance of green stripes on the surface of the fruit. These results indicate that CaPP2C35 may be involved in the formation of light-green immature fruits by regulating the accumulation of chlorophyll content in the exocarp. Thus, these findings lay the foundation for further studies and genetic improvement of immature-fruit color in pepper.

Therapeutic promise of carotenoids as antioxidants and anti-inflammatory agents in neurodegenerative disorders

Neurodegenerative disorders (NDs) including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, Huntington's disease, and multiple sclerosis have various disease-specific causal factors and pathological features. A very common characteristic of NDs is oxidative stress (OS), which takes place due to the elevated generation of reactive oxygen species during the progression of NDs. Furthermore, the pathological condition of NDs including an increased level of protein aggregates can further lead to chronic inflammation because of the microglial activation. Carotenoids (CTs) are naturally occurring pigments that play a significant role in averting brain disorders. More than 750 CTs are present in nature, and they are widely available in plants, microorganisms, and animals. CTs are accountable for the red, yellow, and orange pigments in several animals and plants, and these colors usually indicate various types of CTs. CTs exert various bioactive properties because of its characteristic structure, including anti-inflammatory and antioxidant properties. Due to the protective properties of CTs, levels of CTs in the human body have been markedly linked with the prevention and treatment of multiple diseases including NDs. In this review, we have summarized the relationship between OS, neuroinflammation, and NDs. In addition, we have also particularly focused on the antioxidants and anti-inflammatory properties of CTs in the management of NDs.

Bacterial Carotenoids: Extraction, Characterization, and Applications

Natural carotenoids are secondary metabolites that exhibit antioxidant, anti-inflammatory, and anti-cancer properties. These types of compounds are highly demanded by pharmaceutical, cosmetic, nutraceutical, and food industries, leading to the search for new natural sources of carotenoids. In recent years, the production of carotenoids from bacteria has become of great interest for industrial applications. In addition to carotenoids with C40-skeletons, some bacteria have the ability to synthesize characteristic carotenoids with C30-skeletons. In this regard, a great variety of methodologies for the extraction and identification of bacterial carotenoids has been reported and this is the first review that condenses most of this information. To understand the diversity of carotenoids from bacteria, we present their biosynthetic origin in order to focus on the methodologies employed in their extraction and characterization. Special emphasis has been made on high-performance liquid chromatography-mass spectrometry (HPLC-MS) for the analysis and identification of bacterial carotenoids. We end up this review showing their potential commercial use. This review is proposed as a guide for the identification of these metabolites, which are frequently reported in new bacteria strains.

Distinguishing between isomeric neoxanthin and violaxanthin esters in yellow flower petals using liquid chromatography/photodiode array atmospheric pressure chemical ionization mass spectrometry and tandem mass spectrometry

RATIONALE

Liquid chromatography/photodiode array atmospheric pressure chemical ionization mass spectrometry (LC/PDA-APCI-MS) is used for the analysis of various carotenoid pigments in plants. Among them, it is difficult to distinguish between the isomeric violaxanthin/neoxanthin esters.

METHODS

The yellow pigments of tomato petals were extracted with acetone, and the extracts were kept at -30°C to allow the contaminating triacylglycerols to settle out physically. The supernatants were analyzed using LC/PDA-APCI-MS with a high-resolution orbitrap mass spectrometer for their exact masses. The expected carotenoid esters were calculated with the combination of carotenoids and fatty acids, and they were matched with the experimental exact masses. The fatty acid structures in the carotenoid esters were also identified using collision-induced dissociation (CID) tandem mass spectrometry (MS/MS). The isomeric violaxanthin/neoxanthin esters were distinguished using CID MS/MS from their in-source dehydrated product ions as pseudoprecursor ions.

RESULTS

The in-source dehydrated ions [M - H₂ O + H]⁺ of neoxanthin diesters predominated over their protonated molecules [M + H]⁺ in LC/MS. By contrast, the protonated molecules of violaxanthin diesters predominated. The 92 u loss product ions [M - H₂ O - C₇ H₈  + H]⁺ were observed from the dehydrated violaxanthin diesters, but they were not generated from the dehydrated neoxanthin diesters in the CID MS/MS of their dehydrated pseudoprecursor ion [M - H₂ O + H]⁺ .

CONCLUSIONS

The allene allyl carbocation in neoxanthin diesters was generated from dehydration after preferential protonation at the hydroxy group. The epoxide group of violaxanthin diesters opens easily after protonation; however, the dehydration did not proceed at this stage. The 92 u loss of C₇ H₈ was explained by an intramolecular [2 + 2] cycloaddition, which proceeded preferentially in dehydrated violaxanthin diesters because the carbocations in the dehydrated species were conjugated to the polyene and those double bonds were depolarized during CID MS/MS. Therefore, the isomeric neoxanthin/violaxanthin diesters were distinguished using LC/PDA-APCI-MS and MS/MS. This method was a practical and useful method of profiling the carotenoid esters of the yellow petals.

Carotenogenesis of Staphylococcus aureus: New insights and impact on membrane biophysical properties

Staphyloxanthin (STX) is a saccharolipid derived from a carotenoid in Staphylococcus aureus involved in oxidative-stress tolerance and antimicrobial peptide resistance. STX influences the biophysical properties of the bacterial membrane and has been associated to the formation of lipid domains in the regulation of methicillin-resistance. In this work, a targeted metabolomics and biophysical characterization study was carried out to investigate the biosynthetic pathways of carotenoids, and their impact on the membrane biophysical properties. Five different S. aureus strains were investigated, including three wild-type strains containing the crtM gene related to STX biosynthesis, a crtM-deletion mutant, and a crtMN plasmid-complemented variant. LC-DAD-MS/MS analysis of extracts allowed the identification of 34 metabolites related to carotenogenesis in S. aureus at different growth phases (8, 24 and 48 h), showing the progression of these metabolites as the bacteria advances into the stationary phase. For the first time, 22 members of a large family of carotenoids were identified, including STX and STX-homologues, as well as Dehydro-STX and Dehydro-STX-homologues. Moreover, thermotropic behavior of the CH2 stretch of lipid acyl chains in live cells by FTIR, show that the presence of STX increases acyl chain order at the bacterial growth temperature. Indeed, the cooperative melting event of the bacterial membrane, which occurs around 15 °C in the native strains, shifts with increased carotenoid content. These results show the diversity biosynthetic of carotenoids in S. aureus, and their influence on membrane biophysical properties.

A new voltammetric approach for the determination of β-carotene in vegetables and pharmaceutical capsules using a gold electrode

Significant improvements in the voltammetric determination of β-carotene (BCA) have been achieved, mainly by the replacement of toxic dichloromethane with acetone and using non-mercury electrode. The respective procedure is based on anodic oxidation of BCA at a gold electrode in the disc configuration, when using square-wave voltammetry in pure acetone (99.8%) with 0.1 mol L^-1 LiClO₄ as the supporting electrolyte. The method comprises extraction of the analyte from the sample with acetone, thus avoiding the usually used highly toxic solvents. Analytically, it can be characterized by a linear range from 6.0 × 10^-6 to 5.9 × 10^-4 mol L^-1 with regression equation I_p^a = 0.0184c -0.1631 and correlation coefficient, R² = 0.9998, limits of detection and quantification LOD = 1.6 × 10^-6 mol L^-1 and LOQ = 5.4 × 10^-6 mol L^-1, respectively; both being obtained at a potential step of 5 mV, with the pulse amplitude of 25 mV, and a frequency of 80 Hz. After optimization, the method was evaluated in series of analyses; namely, with two samples of vegetables and two pharmaceutical preparations (capsules), when the results could be compared to those of a reference spectrophotometric method. Due to a simple instrumentation, including sample preparation, the voltammetric method for the determination of BCA can be recommended as a quick screening assay in food and pharmaceutical analysis.

Design and Nutrient Analysis of a Carotenoid-Rich Food Product to Address Vitamin A and Protein Deficiency

Worldwide undernutrition affects over 820 million individuals and is the underlying cause of over 50% of all childhood deaths. Sweet potatoes have been promoted to address vitamin A (vitA) deficiency, with a single, orange-fleshed sweet potato (OFSP) providing enough vitA, as β-carotene, to meet daily needs. However, the bioavailability of β-carotene is dependent on the presence of dietary fat, which is not provided by OFSP, and it lacks some essential amino acids. Therefore, in an attempt to create a food product that meets daily vitA requirements with adequate bioavailability and complete protein, we designed and assessed a sweet potato, peanut paste, and legume product. The final food product formulation, developed through computer modeling, resulted in a 65/5/35 (w/w/w) formulation in a 250 g serving and ~330 kcal. We then confirmed the nutrient content of macronutrients, and essential amino acids, zinc, and iron contents. Total β-carotene was assessed by HPLC and was lower than predicted through computer modeling, likely due to losses through thermal processing and/or degradation from storage. The results of this project indicate that the three ingredients can be combined into a single 250 g food product to provide >300 kcal energy, complete protein, and micronutrients in a more bioavailable form.