Bioactive feruloylated xylooligosaccharides derived from Pearl millet (Pennisetum glaucum) bran with antiglycation and antioxidant properties

Unraveling the nutritional potential of millet by-products through extraction of high value compounds for the development of novel food products

Millets are drought-resistant crops that generate significant amount of by-products (bran, husk, stalk etc.) during harvesting and processing. These by-products are storehouse of nutrients and high value compounds including polyphenols, dietary fiber, proteins etc. However, these by-products remain underutilized and generally discarded, burned or used as feedstock causing adverse impact on the environment and human health in addition to loss of valuable nutrients. Therefore, the valorization of millet by-products offers sustainable approach to enhance food product innovation while reducing agricultural waste. Green extraction techniques can be employed to recover antioxidants, phenolics, and bioactive peptides from these by-products. The incorporation of these ingredients into food products can significantly improve the nutritional profile, functional characteristics, like antioxidant, prebiotic, anti-diabetic, and anticarcinogenic properties. The review highlights the feasibility of upcycling millet by-products into high-value components, which can address the growing demand for health-oriented food products contributing towards food security, sustainability and circular economy.

Arabinoxylan from pearl millet bran: Optimized extraction, structural characterization, and its bioactivities

Arabinoxylan (AX) from cereals and millets have garnered attention due to the myriad of their bioactivities. Pearl millet (Pennisetum glaucum) bran, an underexplored milling by-product was used to extract AX (PMAX) by optimized alkali-assisted extraction using Response Surface Methodology and Central Composite Design, achieving a yield of 15.96 ± 0.39 % (w/w) under optimal conditions (0.57 M NaOH, 1:17 g/mL solid-to-liquid ratio, 60 °C, 4 h). Structural analysis revealed that PMAX was primarily composed of arabinose, xylose, glucose, galactose, and mannose (molar ratio 45.1:36.1:10.4:7.1:1.8), with a highly substituted (1 → 4)-linked β-D-xylopyranose backbone and a molecular weight of 794.88 kDa. PMAX displayed a significant reducing power of 0.617, metal chelating activity of 51.72 %, and DPPH, and ABTS radical scavenging activities (64.43 and 75.4 %, respectively at 5 mg/mL). It also demonstrated anti-glycation effects by inhibiting fructosamine (52.5 %), protein carbonyl (53.6 %), and total advanced glycation end products (77.0 %) formation, and reduced protein oxidation products such as dityrosine (84.7 %), kynurenine (80.2 %), and N'-formyl-kynurenine (50.0 %) at 5 mg/mL. PMAX induced the growth of Lactobacillus spp. in vitro and modulate gut microbiota in male Wistar rats by increasing Bacteroidetes and decreasing Firmicutes. These results provide a basis for further research on pearl millet arabinoxylan and its possible nutraceutical application.

Harnessing the nutritional profile and health benefits of millets: a solution to global food security problems

India is dealing with both nutritional and agricultural issues. The maximum area of agricultural land with irrigation capabilities has been largely utilized, while the amount of dry land is expanding. The influence is distinct on farmer's livelihoods and earnings, which ultimately affects nutritional security. In order to attain nutritional security and the goal of SDG (Sustainable Development Goals), millets are sustainable solutions, with respect to high nutritional content, bioactive and medicinal properties, and climate resilience. The nutrient profile of millet includes 60%-70% carbohydrate content, 3.5%-5.2% fat, and 7.52%-12.1% protein sources. A wide spectrum of amino acids, including cysteine, isoleucine, arginine, leucine, tryptophan, lysine, histidine, methionine, tyrosine, phenylalanine, threonine, and valine are generally present in millets. Mineral content in millets includes calcium, phosphorus, potassium, sodium, and magnesium. Additionally, millets are an excellent source of bioactive molecules such as polyphenol, phenolic acid, flavonoids, active peptides, and soluble fiber, which have a wide range of therapeutic applications, including the prevention of free radical damage, diabetes, anti-microbial, anti- biofilm, and anti-cancer effects. This review will focus on the nutritional profile and health benefits of millet considering the present-day food security problems.

SIRT1/AMPK-mediated pathway: Ferulic acid from sugar beet pulp mitigating obesity-induced diabetes-linked complications and improving metabolic health

Obesity-induced type 2 diabetes (T2D) increases the risk of metabolic syndrome due to the high calorie intake. The role of sugar beet pulp (SBP) in T2D and the mechanism of its action remain unclear, though it is abundant in phenolics and has antioxidant activity. In this study, we isolated and purified ferulic acid from SBP, referred to as SBP-E, and studied the underlying molecular mechanisms in the regulation of glucose and lipid metabolism developing high glucose/high fat diet-induced diabetic models in vitro and in vivo. SBP-E showed no cytotoxicity and reduced the oxidative stress by increasing glutathione (GSH) in human liver (HepG2) and rat skeletal muscle (L6) cells. It also decreased body weight gain, food intake, fasting blood glucose levels (FBGL), glucose intolerance, hepatic steatosis, and lipid accumulation. Additionally, SBP-E decreased the oxidative stress and improved the antioxidant enzyme levels in high-fat diet (HFD)-induced T2D mice. Further, SBP-E reduced plasma and liver advanced glycation end products (AGEs), malondialdehyde (MDA), and pro-inflammatory cytokines, and increased anti-inflammatory cytokines in HFD-fed mice. Importantly, SBP-E significantly elevated AMPK, glucose transporter, SIRT1 activity, and Nrf2 expression and decreased ACC activity and SREBP1 levels in diabetic models. Collectively, our study results suggest that SBP-E treatment can improve obesity-induced T2D by regulating glucose and lipid metabolism via SIRT1/AMPK signalling and the AMPK/SREBP1/ACC1 pathway.

Extraction optimization, partial purification, and characterization of sialoglycoproteins from Labeo rohita roes

In India, fish roes are generally considered worthless garbage and disposed of without recovering the valuable molecules, creating environmental and disposal problems. The present investigation aimed to optimize the extraction conditions, partial purification, and characterization of sialoglycoproteins (RRSGP) from Labeo rohita (rohu) roes. RSM generated optimum conditions for maximum RRSGP (70.49 %) extraction, which were 1.25 M NaCl, 1:32.5(w/v) solid-to-liquid ratio, 47.5 °C temperature, and 3 h time. Further, sialoglycoproteins from RRSGPs were partially purified, and result revealed that obtained peak-1 (PRRSGP) using QFF anion exchange chromatography exhibited higher glycoprotein and sialic acid content (p < 0.05). SDS-PAGE pattern of PRRSGP presented dominant bands of 97 kDa and 27 kDa glycoproteins. FTIR spectrum of PRRSGP confirmed the presence of glycated proteins. HPLC analysis revealed that PRRSGP consists of Neu5Ac. Furthermore, β-elimination reaction elucidated that PRRSGP contained N-glycosidic linkage. PRRSGP exhibited tyrosine and glutamate as primary amino acids. Glycan part of PRRSGP presented mannose and N-acetyl galactosamine as dominant neutral and amino sugar, respectively. Furthermore, PRRSGP exhibited antioxidant activity with EC50 value for DPPH (8.79 mg/ml) and ABTS (2.21 mg/ml). Besides, RRSGP displayed better protein solubility, foaming, and emulsion properties. Therefore, rohu roes are potential source of sialoglycoproteins that can be recovered and used as bio-functional ingredients in food and nutraceutical applications.

Finger Millet Seed Coat-A Functional Nutrient-Rich Cereal By-Product

Finger millet (FM) is one of the little millets grown in Asia and Africa. Although still classified as an "orphan crop", there is an increasing interest in the research of FM seed coat (FMSC), also known as bran. It houses 90% of the seed's polyphenols and dietary fibre. The calcium and phosphorus content of FMSC is about 6- to 25-fold that of other cereals. FMSC is specifically beneficial for its polyphenols, arabinoxylans, phytates, and flavonoids content. Evidence of the hypoglycaemic, nephroprotective, hypocholesterolemic, and anti-cataractogenic effects of FMSC has been substantiated, thereby supporting the health claims and validating its nutraceutical potential for diabetics. This article discusses FMSC extraction and nutritional properties, focusing on arabinoxylan and polyphenols, their potential health benefits, and their application in food formulations. Although there is a dearth of information on using FMSC in food formulation, this review will be a data repository for further studies on FMSC.