Ramesh Kumar Saini

Carotenoids from fruits and vegetables: Chemistry, analysis, occurrence, bioavailability and biological activities

Fruits and vegetables are generally considered as important contributors to a healthy diet and their intake is extremely helpful to reduce the risk of specific diseases like cancers, cardiovascular diseases, neural tube defects, and cataracts. Bioactive constituents from fruits and vegetables, such as carotenoids, folic acid and dietary fiber appear to play important roles in the prevention of these diseases. Carotenoids and their derivatives are versatile isoprenoids and play a vital role in plants and animals, starting from cellular antioxidant to gene regulation and so their importance at cellular and molecular level is well established. The most significant aspect of carotenoids in our diet is the antioxidant and provitamin A activity, and also the color that they impart to our food. The composition and bioavailability of carotenoids in food are significantly influenced by processing and other post-harvest technologies. This review discusses the theoretical aspects and recent developments in structural properties, biosynthesis and enhancement, processing, methods of analysis, composition in fruits and vegetables, and bioaccessibility and bioavailability of carotenoids. Additionally, future research challenges in this context are identified.

Efficiency of RAPD, SSR and Cytochrome P450 gene based markers in accessing genetic variability amongst finger millet (Eleusine coracana) accessions

Finger millet (Eleusine coracana L.) is an important crop used for food, forage, and industrial products. Three DNA marker techniques, random amplified polymorphic DNA (RAPD), simple sequence repeat (SSR) and cytochrome P450 gene based markers were used for the detection of genetic polymorphism in 83 accessions of finger millet collected from various geographical regions of India and Africa. A total of 18 RAPD, 10 SSR and 10 pairs of cytochrome P450 gene based markers were generated 56.17, 70.19 and 54.29% polymorphism, respectively. Mean polymorphism information content (PIC) for each of these marker systems (0.280 for RAPD, 0.89 for SSR and 0.327 for cytochrome P450 gene based markers) suggested that SSR marker were highly effective in determining polymorphism. The phenograms based on the three markers data indicate that genotypes from different geographical regions are clearly distinguishable as separate clusters. Mantel test employed for detection of goodness of fit established cophenetic correlation values above 0.90 for all the three marker systems. The dendrograms and PCA plots derived from the binary data matrices of the three marker systems are highly concordant. High bootstrap values were obtained at major nodes of phenograms through WINBOOT software. Based on the results of present study, SSR and cytochrome P450 gene based markers appear to be particularly useful for the estimation of genetic diversity. This study reveals the potential of RAPD, SSR and gene based markers for characterizing germplasm of Eleusine coracana and narrow down the vast germplasm into distinct core groups.

Carotenoid extraction methods: A review of recent developments

The versatile use of carotenoids in feed, food, cosmetic and pharmaceutical industries has emphasized the optimization of extraction methods to obtain the highest recovery. The choice of method for carotenoid extraction from food matrices is crucial, owing to the presence of diverse carotenoids with varied levels of polarity, and the presence of various physical and chemical barriers in the food matrices. This review highlights the theoretical aspects and recent developments of various conventional and nonconventional methods used for the extraction of carotenoids, including ultrasound-assisted extraction (UAE), pressurized liquid extraction (PLE), and supercritical fluid extraction (SFE). Recent applications of non-toxic and environmentally safe solvents (green solvents) and ionic liquids (IL) for carotenoid extraction are also described. Additionally, future research challenges in the context of carotenoids extractions are also identified.

Dietary iron supplements and Moringa oleifera leaves influence the liver hepcidin messenger RNA expression and biochemical indices of iron status in rats

In this study, the effects of iron depletion and repletion on biochemical and molecular indices of iron status were investigated in growing male Wistar rats. We hypothesized that iron from Moringa leaves could overcome the effects of iron deficiency and modulate the expression of iron-responsive genes better than conventional iron supplements. Iron deficiency was induced by feeding rats an iron-deficient diet for 10 weeks, whereas control rats were maintained on an iron-sufficient diet (35.0-mg Fe/kg diet). After the depletion period, animals were repleted with different source of iron, in combination with ascorbic acid. Iron deficiency caused a significant (P < .05) decrease in serum iron and ferritin levels by 57% and 40%, respectively, as compared with nondepleted control animals. Significant changes in the expression (0.5- to100-fold) of liver hepcidin (HAMP), transferrin, transferrin receptor-2, hemochromatosis type 2, ferroportin 1, ceruloplasmin, and ferritin-H were recorded in iron-depleted and iron-repleted rats, as compared with nondepleted rats (P < .05). Dietary iron from Moringa leaf was found to be superior compared with ferric citrate in overcoming the effects of iron deficiency in rats. These results suggest that changes in the relative expression of liver hepcidin messenger RNA can be used as a sensitive molecular marker for iron deficiency.

Folates: Chemistry, analysis, occurrence, biofortification and bioavailability

Folates (Vitamin B9) include both naturally occurring folates and synthetic folic acid used in fortified foods and dietary supplements. Folate deficiency causes severe abnormalities in one-carbon metabolism can result chronic diseases and developmental disorders, including neural tube defects. Mammalian cells cannot synthesize folates de novo; therefore, diet and dietary supplements are the only way to attain daily folate requirements. In the last decade, significant advancements have been made to enhance the folate content of rice, tomato, common bean and lettuce by using genetic engineering approaches. Strategies have been developed to improve the stability of folate pool in plants. Folate deglutamylation through food processing and thermal treatment has the potential to enhance the bioavailability of folate. This review highlights the recent developments in biosynthesis, composition, bioavailability, enhanced production by elicitation and metabolic engineering, and methods of analysis of folate in food. Additionally, future perspectives in this context are identified. Detailed knowledge of folate biosynthesis, degradation and salvage are the prime requirements to efficiently engineer the plants for the enhancement of overall folate content. Similarly, consumption of a folate-rich diet with enhanced bioavailability is the best way to maintain optimum folate levels in the body.

Progress in Microbial Carotenoids Production

Carotenoids are versatile isoprenoids pigments, play a vital role in the cellular system, starting from antioxidant to gene regulation. Carotenoids are widely used in food, nutraceuticals, and cosmetics owing to their vitamin A, antioxidant and anticancer activities. The demand of carotenoids in various sectors has triggered the research to explore a commercially viable and environmentally friendly production. This article presents a short review of progress in carotenoids production from microbial platforms.

Augmentation of major isoflavones in Glycine max L. through the elicitor-mediated approach

Abstract - Isoflavone content in soybean seeds was enhanced by the elicitor-mediated approach under field conditions through the floral application of abiotic elicitors-salicylic acid, methyl jasmonate and biotic elicitors-Aspergillus niger and Rhizopus oligosporus. Among isoflavones, daidzein and glycitein were found to be highly responsive to elicitors, with an increase of 53.7% and 78.7%, respectively as compared to control. Highest total isoflavone content (1276.4 mg g-1 of seeds) was observed upon the administration of 0.1 mMsalicylic acid, which is 92.7% higher than in control. This study would be valuable for augmentation of the isoflavone content in soybean seeds in field grown plants for better nutraceutical potential.

Omega-3 and omega-6 polyunsaturated fatty acids: Dietary sources, metabolism, and significance — A review

Linoleic acid (LA) (n-6) and α-linolenic acid (ALA) (n-3) are essential fatty acids (EFAs) as they cannot be synthesized by humans or other higher animals. In the human body, these fatty acids (FAs) give rise to arachidonic acid (ARA, n-6), eicosapentaenoic acid (EPA, n-3), and docosahexaenoic acid (DHA, n-3) that play key roles in regulating body homeostasis. Locally acting bioactive signaling lipids called eicosanoids derived from these FAs also regulate diverse homeostatic processes. In general, ARA gives rise to pro-inflammatory eicosanoids whereas EPA and DHA give rise to anti-inflammatory eicosanoids. Thus, a proportionally higher consumption of n-3 PUFAs can protect us against inflammatory diseases, cancer, cardiovascular diseases, and other chronic diseases. The present review summarizes major sources, intake, and global consumption of n-3 and n-6 PUFAs. Their metabolism to biosynthesize long-chain PUFAs and eicosanoids and their roles in brain metabolism, cardiovascular disease, obesity, cancer, and bone health are also discussed.

Metabolite profiling of green, green/red, and red lettuce cultivars: Variation in health beneficial compounds and antioxidant potential

Salad vegetables, commonly consumed at baby-leaf stages, are the most appropriate and emerging dietary source of antioxidant compounds. Screening and identification of nutrient-rich cultivars can be potentially useful to obtain a nutrient-dense diet. Thus, in this study, we explored the genetic potential of baby leaves of 23 diverse lettuce cultivars for the health-beneficial metabolites. The results showed that the composition and contents of the studied metabolites in lettuces varied significantly between cultivars and were principally dependent on leaf color. All red-leaf cultivars were rich in carotenoids, cyanidin, polyunsaturated fatty acids (PUFAs, primarily in the form of α-linolenic and linoleic acid,) total phenolic contents (TPC), and antioxidant potential. Among carotenoids, all-E-lutein was found in highest amount, followed by all-E-violaxanthin and all-E-lactucaxanthin, accounting for an average of 30%, 28% and 15% of total carotenoids, respectively. The content of total folate was recorded in the range of 6.51 (cv. Caesar Green) to 9.73μg/g (DW) (cv. Asia Heuk Romaine). The principal component analysis (PCA) showed that the cyanidin and other phenolic compounds are the most potent scavengers of ABTS and DPPH radicals. The overall results suggested that all red-leaf lettuce cultivars have a distinct profile of phytoconstituents, which can be used as a nutrient-dense food.

Minimally processed ready-to-eat baby-leaf vegetables: Production, processing, storage, microbial safety, and nutritional potential

ABSTRACT The market for minimally processed ready-to-eat (RTE) baby-leaf vegetables (BLVs) has been rapidly growing and offering to consumers convenient and appealing products, rich in health beneficial bioactive compounds. These vegetables are harvested at a very early stage of maturation and prepared with minimal processing methods such as cutting, washing, rinsing, and packaging with the modified atmosphere of O2, CO2, and relative humidity (RH). Maintenance of microbial safety, color, texture, aroma, and nutrients are the major problems associated with commercial production and marketing of BLVs. This review discusses the theoretical aspects and recent developments in the maintenance of nutritional quality and microbial safety during production, processing, sanitization, packaging, and storage of BLVs. The varietal improvements in BLVs for wider adaptability and disease resistance are also discussed. Additionally, future research challenges in these contexts are identified.