T.S. Chandra

Bio: T.S. Chandra is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topic(s): Eleusine & Xylanase. The author has an hindex of 27, co-authored 67 publication(s) receiving 2395 citation(s). Previous affiliations of T.S. Chandra include Indian Institutes of Technology & Indian Institute of Science.

Changes in carbohydrate, free amino acids, organic acids, phytate and HCl extractability of minerals during germination and fermentation of finger millet (Eleusine coracana)

Abstract: Finger millet (Eleusine coracana) also known as ‘ragi’ in India is a source of carbohydrate, protein and mineral that is comparable to other common cereal grains. However, antinutrients like phytate and tannins reduce the nutrient bioavailability which can be improved by suitable processing methods such as germination and fermentation. In our study, the finger millet was germinated (24 h) and then subjected to fermentation (48 h). Major biochemical changes occurred during fermentation (6–18 h) compared to germination (24 h). The processing decreased the pH from 5.8 to 3.8 and increased the total sugars (2-fold), reducing sugars (13-fold) and free amino acids (10-fold). Lactic acid was the predominant organic acid (3.7%). The phytate content decreased by 60% with an increase in HCl-extractable minerals of 47%. The phytate × Ca/Zn molar ratio decreased from 163 to 66.2, indicative of an increased Zn bioavailability. In conclusion, a combination of germination and fermentation is a potential process for decreasing the antinutrient levels and enhancing digestibility.

Development of carbon nanotubes and nanofluids based microbial fuel cell

Abstract: In the present study, the construction of a novel microbial fuel cell (MFC) using novel electron mediators and carbon nanotube (CNT) based electrodes has been discussed. The novel mediators are nanofluids which were prepared by dispersing nanocrystalline platinum anchored carbon nanotubes (CNTs) in water. A cation selective membrane separates the two chambers of the MFC with hexacyanoferrate as the ultimate electron acceptor in the cathode compartment. Performance of the new Escherichia coli based MFC was compared to the previously reported E. coli based microbial fuel cells with Neutral Red (NR) and Methylene Blue (MB) electron mediators. The performance of the MFC using CNT based nanofluids and CNT based electrodes has been compared against plain graphite electrode-based MFC. CNT based electrodes showed as high as ∼6-fold increase in the power density (2470 mW/m 2 ) compared to graphite electrodes (386 mW/m 2 ). The present work demonstrates the potential of noble metal nanoparticles dispersed on CNTs based MFC for the generation of high energies from even simple bacteria like E. coli .

Effects of the antioxidant properties of millet species on oxidative stress and glycemic status in alloxan-induced rats

Abstract: Reactive oxygen species play a significant role in accelerating the complications of diabetes mellitus, and antioxidants alleviate these effects Finger millet (FM; Eleusine coracana) and kodo millet (KM; Paspalum scrobiculatum) are rich sources of phenolics, tannins, and phytates, which can act as antioxidants Hence, the beneficial role of a millet-based diet in protecting against oxidative stress and maintaining glucose levels in vivo in type II diabetes was investigated Whole grain flour of finger millet and KM was incorporated at 55% by weight in the basal diet fed to alloxan-induced diabetic rats over a period of 28 days Blood glucose, cholesterol, enzymatic and nonenzymatic antioxidants, lipid peroxides in blood plasma, and glycation of tail tendon collagen were measured The rats fed the KM-enriched diet showed a greater reduction in blood glucose (42%) and cholesterol (27%) than those fed the finger millet (36% and 13%) The levels of enzymatic (glutathione, vitamins E and C) and nonenzymatic antioxidants (superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase) and lipid peroxides were significantly reduced in diabetic animals and restored to normal levels in the millet-fed groups Glycation of tail tendon collagen was only 40% in the finger millet–fed rats and 47% in the KM-fed rats compared to the controls Diets containing whole grain millet meal flour can protect against hyperglycemic and alloxan-induced oxidative stress in Wistar rats

Production of surfactant and detergent-stable, halophilic, and alkalitolerant alpha-amylase by a moderately halophilic Bacillus sp. Strain TSCVKK.

Abstract: A moderately halophilic alkalitolerant Bacillus sp. Strain TSCVKK, with an ability to produce extracellular halophilic, alkalitolerant, surfactant, and detergent-stable alpha-amylase was isolated from soil samples obtained from a salt-manufacturing industry in Chennai. The culture conditions for higher amylase production were optimized with respect to NaCl, substrate, pH, and temperature. Maximum amylase production of 592 mU/ml was achieved in the medium at 48 h with 10% NaCl, 1% dextrin, 0.4% yeast extract, 0.2% tryptone, and 0.2% CaCl2 at pH 8.0 at 30 °C. The enzyme activity in the culture supernatant was highest with 10% NaCl at pH 7.5 and 55 °C. The amylase that was partially purified by acetone precipitation was highly stable in various surfactants and detergents. Glucose, maltose, and maltooligosaccharides were the main end products of starch hydrolysis indicating that it is an alpha-amylase.

Antinutrient reduction and enhancement in protein, starch, and mineral availability in fermented flour of finger millet (Eleusine coracana)

Abstract: Finger millet, a highly nutritious millet consumed by populations in South India, is a rich source of minerals and dietary fiber in addition to primary nutrients. However, it also has nutrient binding components such as phytate, phenols, tannins, and trypsin inhibitors. Fermentation of finger millet flour using endogenous grain microflora showed a significant reduction of these components (phytate by 20%, phenols by 20%, tannins by 52%, and trypsin inhibitor activity by 32%) at the end of 24 h. There was a simultaneous increase in HCl mineral extractability (Ca, 20%; P, 26%; Fe, 27%; Zn, 26%; Cu, 78%; Mn, 10%), soluble protein, in vitro protein digestibility (23%), and starch digestibility. Keywords: Finger millet; Eleucine coracana; fermentation; phytate; phenols; tannins; trypsin inhibitors; minerals; in vitro digestibility

Xylanases, xylanase families and extremophilic xylanases

Abstract: Xylanases are hydrolytic enzymes which randomly cleave the β 1,4 backbone of the complex plant cell wall polysaccharide xylan. Diverse forms of these enzymes exist, displaying varying folds, mechanisms of action, substrate specificities, hydrolytic activities (yields, rates and products) and physicochemical characteristics. Research has mainly focused on only two of the xylanase containing glycoside hydrolase families, namely families 10 and 11, yet enzymes with xylanase activity belonging to families 5, 7, 8 and 43 have also been identified and studied, albeit to a lesser extent. Driven by industrial demands for enzymes that can operate under process conditions, a number of extremophilic xylanases have been isolated, in particular those from thermophiles, alkaliphiles and acidiphiles, while little attention has been paid to cold-adapted xylanases. Here, the diverse physicochemical and functional characteristics, as well as the folds and mechanisms of action of all six xylanase containing families will be discussed. The adaptation strategies of the extremophilic xylanases isolated to date and the potential industrial applications of these enzymes will also be presented.

Phenolics and polyphenolics in foods, beverages and spices: Antioxidant activity and health effects – A review

Abstract: This review reports on the latest research results and applications of phenolic and polyphenolic compounds. Phenolic compounds, ubiquitous in plants, are an essential part of the human diet and are of considerable interest due to their antioxidant properties and potential beneficial health effects. These compounds range structurally from a simple phenolic molecule to complex high-molecular-weight polymers. There is increasing evidence that consumption of a variety of phenolic compounds present in foods may lower the risk of health disorders because of their antioxidant activity. When added to foods, antioxidants control rancidity development, retard the formation of toxic oxidation products, maintain nutritional quality, and extend the shelf-life of products. Due to safety concerns and limitation on the use of synthetic antioxidants, natural antioxidants obtained from edible materials, edible by-products and residual sources have been of increasing interest. This contribution summarizes both the synthetic and natural phenolic antioxidants, emphasizing their mode of action, health effects, degradation products and toxicology. In addition, sources of phenolic antioxidants are discussed in detail.

Microbial xylanases and their industrial applications: a review.

Abstract: Despite an increased knowledge of microbial xylanolytic systems in the past few years, further studies are required to achieve a complete understanding of the mechanism of xylan degradation by microorganisms and their enzymes. The enzyme system used by microbes for the metabolism of xylan is the most important tool for investigating the use of the second most abundant polysaccharide (xylan) in nature. Recent studies on microbial xylanolytic systems have generally focussed on induction of enzyme production under different conditions, purification, characterization, molecular cloning and expression, and use of enzyme predominantly for pulp bleaching. Rationale approaches to achieve these goals require a detailed knowledge of the regulatory mechanism governing enzyme production. This review will focus on complex xylan structure and the microbial enzyme complex involved in its complete breakdown, studies on xylanase regulation and production and their potential industrial applications, with special reference to biobleaching.

Phenolics in food and nutraceuticals

Abstract: Phenolics in Food and Nutraceuticals is the first single-source compendium of essential information concerning food phenolics. This unique book reports the classification and nomenclature of phenolics, their occurrence in food and nutraceuticals, chemistry and applications, and nutritional and health effects. In addition, it describes antioxidant activity of phenolics in food and nutraceuticals as well as methods for analysis and quantification. Each chapter concludes with an extensive bibliography for further reading. Food scientists, nutritionists, chemists, biochemists, and health professionals will find this book valuable.

Xylanases from fungi: properties and industrial applications

Abstract: Xylan is the principal type of hemicellulose. It is a linear polymer of beta-D-xylopyranosyl units linked by (1-4) glycosidic bonds. In nature, the polysaccharide backbone may be added to 4-O-methyl-alpha-D-glucuronopyranosyl units, acetyl groups, alpha-L-arabinofuranosyl, etc., in variable proportions. An enzymatic complex is responsible for the hydrolysis of xylan, but the main enzymes involved are endo-1,4-beta-xylanase and beta-xylosidase. These enzymes are produced by fungi, bacteria, yeast, marine algae, protozoans, snails, crustaceans, insect, seeds, etc., but the principal commercial source is filamentous fungi. Recently, there has been much industrial interest in xylan and its hydrolytic enzymatic complex, as a supplement in animal feed, for the manufacture of bread, food and drinks, textiles, bleaching of cellulose pulp, ethanol and xylitol production. This review describes some properties of xylan and its metabolism, as well as the biochemical properties of xylanases and their commercial applications.