Rekha S. Singhal's research while affiliated with Institute of Chemical Technology, Mumbai and other places

Publications (432)

Article
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The present study evaluates the in vitro antioxidant, anti-diabetic potential and 1-deoxynojirimycin content in hydro-ethanolic leaf extracts of eight Indian mulberry cultivars (V-1, K-2, S-36, S-13, BER-779, BER-763, BER-1 and Anantha). Subsequently, for the selected variety ultrasound-probe assisted extraction parameters (power, liquid to solid r...
Article
Multiple microbial exopolysaccharides have been reported in recent decade with their structural and functional features. Gellan gum (GG) is among these emerging biopolymer with versatile properties. Low production yield, high downstream cost, and abundant market demand have made GG a high cost material. Hence, an understanding on the various possib...
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Full-text available
β-Mannanase capable of hydrolyzing β-1,4-linkages in guar gum was immobilized as cross-linked enzyme aggregates (M-CLEAs). The aggregation and cross-linking process was optimized by response surface methodology (RSM) for maximum activity. The resulting M-CLEAs were characterized by FTIR, DSC, SEM, and SDS-PAGE. The M-CLEAs showed higher pH stabilit...
Article
Molecular imprinting has received great attention in recent years for the analysis of a wide range of analytes in food matrices. The highly complex nature of the food matrix further adds to the need for intricate extraction and analysis. Molecularly imprinted polymers (MIPs) deal with the construction of a polymer in the presence of a template, whi...
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The present investigation was aimed at preparing hydrogels from galactomannans extracted from the defatted seeds of Leucaena leucocephala (subabul) (SGM) and κ-carrageenan (кC) in an aqueous phase (pH 6.8) using KCl as ionic crosslinker. The dynamic moduli (G’ and G”) and Power law parameters (n’ and n”) of the hydrogels were optimized through full...
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The ubiquity, low cost and biocompatibility make polysaccharides a material of choice in food, pharmaceutical, cosmeceutical, textile and paper industries. From the age-old process of pectin addition in jams to the latest developments of bio-nanocomposites with polysaccharides in biosensing, developments in applications of polysaccharides and their...
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Traditional tofu from soybeans provides a bunch of health benefits which makes it a staple option in high-protein diets. Concerns on allergenicity/hypercholesterolemia from animal foods and lactose intolerance from dairy based ones have surged the demand for alternative and sustainable plant-based proteins. In this study, a tofu-like coagulated pro...
Chapter
Amine modification of gums is performed with the intention of incorporating a positive charge and/or hydrophobic moiety in the structure of the gum. The incorporation of charge is performed by adding primary amino groups in the polymer chain, and hydrophobicity is introduced via reaction with alkyl or aryl amines. The amine modification of gums can...
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Biomolecules such as sugars and polyphenols are highly polar in nature owing to the abundance of hydroxyl moieties. Although these are employed for several applications in foods and pharmaceuticals, their compromised lipophilicity poses some limitations therein. One of the approaches to introduce lipophilicity in sugars and polyphenols, and consequ...
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With increasing protein needs for the burgeoning population, newer sources of proteins are attracting the attention of scientists globally. Despite having adequate nutritional appeal, many proteins are also lost in waste streams due to their poor functional properties. Besides the nutritional aspect, proteins have been used for controlled release o...
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The use of phytochemicals for nutritional wellness has attracted worldwide attention and resulted in development of innovative formulations. Turmeric latte is one such formulation. However, an in-depth study on its physicochemical properties and oral bioavailability has not been conducted as yet. We present a ready-to-use turmeric latte by microenc...
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The present work was aimed at the valorization of roasted spent coffee grounds (SCG), a major valuable and functional by-product of the coffee processing industry by supercritical fluid extraction (SCFE) of the oil therefrom using carbon dioxide, and utilizing the spent residue for the development of functional cookies. The process parameters of SC...
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The growing health concerns on reused fried oils are addressed globally in terms of total polar materials (TPM) of frying oil (FO). However, consumer perspective mandates the monitoring of absorbed oil (AO). This prompted the evaluation of AO quality by collecting 100 samples of fried products from different cities in India. The TPM of AO extracted...
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Cross-linked enzyme aggregates (CLEAs) of lipase were prepared after fractional precipitation with 40–50% ammonium sulfate and then cross-linking with glutaraldehyde. The process variables for the preparation of lipase-CLEAs such as glutaraldehyde concentration, cross-linking period, and initial pH of medium were optimized. The optimized conditions...
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In the present work, ultrasonic assisted synthesis and characterization of Maillard conjugates of whey protein isolate (WPI) and gellan gum (GG) was carried out and compared with the classical heating method. Conjugation was confirmed by FTIR, secondary structure, intrinsic fluorescence analysis, and degree of glycation (DG). The structural analysi...
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Angiogenesis is a complex physiological process that cannot be treated with single agent therapy. Several edible fungi have been known to encompass bioactive compounds, and are promising sources of multi-component drugs. One such widely consumed edible fungi is Cantharellus cibarius, which has been explored for its biological activities. The presen...
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Whey protein isolate (WPI) hydrolysates have higher solubility in aqueous phase and enhanced biological properties. Hydrolysis of WPI was optimized using operating pressure (ΔP, bar), number of passes (N), and WPI concentration (C, %) as deciding parameters in hydrodynamic cavitation treatment. The optimum conditions for generation of WPI hydrolysa...
Chapter
Over the past several years, the drawbacks associated with the use of various conventional extraction techniques for oleaginous materials have driven the research towards developing greener, efficient, and scalable alternatives. One such promising technique being extensively studied for the extraction of oleaginous materials is three phase partitio...
Article
Anthocyanins were extracted from red rose petals collected from floral waste, and were esterified with fatty acids using the lipase Fermase CALB™ 10000 to enhance their lipophilicity. The process parameters for the extraction of anthocyanin were optimized for extraction time, nature of the solvent, substrate to solvent ratio, and concentration of c...
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Zinc oxide particles (ZnOPs) of both nanometer and sub-micron sizes are important components of high demand consumer products such as sunscreen, paint, textile, food packaging, and agriculture. Their ultimate discharge in the aquatic ecosystem is nearly unavoidable. For sustainable use of ZnOPs, there is an urgent need to assess its ecotoxicity usi...
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Fortification of commodity foods has been accepted as a successful strategy to overcome micronutrient deficiencies. This work evaluates the stability of vitamin B12 and vitamin D3 during different processing techniques and/or storage. Kinetic behavior of vitamins B12 and D3 degradation in fortified whole wheat flour (FWWF) during storage at varying...
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Fungi are a huge source of unexplored bioactive compounds. Owing to their biological activities, several fungi have shown commercial application in the health industry. Tuber aestivum Vittad. is one such edible fungi with an immense scope for practical biological applications. In the present study, the anti-angiogenic activity of petro- leum ether...
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Spray drying is the most commonly used encapsulation technique to stabilize sensitive bioactive compounds and sometimes enhances their performance. Vitamin B12 and vitamin D3 deficiencies are reported worldwide and co-encapsulation can provide a combined solution to this problem. The present work aimed at encapsulation of vitamin B12 and D3 by spra...
Article
Curcumin faces challenges such as poor aqueous solubility and limited bioaccessibility which limits its oral therapeutic applications. This work evaluated the complexation of curcumin using pea protein isolate (PPI, leguminous protein) vis-à-vis whey protein isolate (WPI, animal protein) to overcome these limitations. Thermodynamic parameters (ΔH a...
Chapter
The use of enzymes in food processing is an age-old process. With the advancement of R&D and new technologies, several novel enzymes with wide range of applications have been developed. The present article gives an insight into different microbial enzymes which find applications in food processing. Various type of food processing and the use of enz...
Article
Chitosan and whey protein isolate (WPI) conjugate films were prepared as a novel matrix for encapsulating and extending the postharvest shelf life of strawberries. Film forming solutions of chitosan, WPI, and chitosan-WPI conjugate were mixed with glycerol, casted for films at 60±2°C and assessed for their colour, water vapour and oxygen transfer r...
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Co-crystallization is a popular technique to stabilize active compounds and is widely used in the food and pharmaceutical industry. This work aimed at development and characterization of vitamin B12 fortified co-crystallized sugar cubes. Among the different hydrocolloids used for co-crystallization of sugar cubes, the maximum retention of 97.5% vit...
Article
Supercritical fluid extraction (SFE) was optimized for the extraction of functional seasoning from mixture of flaxseeds, pepper, turmeric and chilli (2:1:1:1) using Box-Behnken design wherein flaxseed oil generated in situ was simultaneously co-extracted with spice constituents which in turn protected the flaxseed oil against oxidation. The best co...
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The therapeutic applications of curcumin, a phenolic compound extracted from Curcuma species, is limited due to poor bioavailability. To enhance the bioavailability, self-microemulsifying drug delivery systems (SMEDDS) with curcumin were prepared. Ethyl oleate, Tween 80, and Transcutol® P with surfactant: co-surfactant ratio of 2:1 w/w was selected...
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Summer truffles (Tuber aestivum) collected from Italy were evaluated for changes in chemical composition and hence in vitro bioactivity on the basis of their maturity. Truffles were classified as immature and mature based on the colour of glebum. Water and methanol extracts of freeze-dried mature truffles demonstrated higher total phenolics, in vit...
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Acrylamidase produced by Cupriavidus oxalaticus ICTDB921 was recovered directly from the fermentation broth by ammonium sulfate (40–50%) precipitation and then stabilized by cross-linking with glutaraldehyde. The optimum conditions for the preparation of cross-linked enzyme aggregates of acrylamidase (acrylamidase-CLEAs) were using 60 mM glutaralde...
Article
One-pot synthesis of caprylic, lauric and palmitic acid mono- and diesters of trehalose was catalyzed by the lipase Fermase CALB™ 10000. An optimized molar conversion of 35% of trehalose to its palmitate esters was obtained in acetone at 60 °C with a trehalose:palmitic acid molar ratio of 1:5 in 4 h. Trehalose fatty acid esters (THFAE) were purifie...
Chapter
India is a country embracing various cultures, languages, climates, religions and communities. By virtue of such diversity, India is blessed with many cuisines employing a variety of ingredients and preparation methods. Thus, Indian traditional foods, which are usually prepared in households or institutions like hotels/restaurants exhibit tremendou...
Article
Kokum fat was extracted using supercritical carbon dioxide extraction (SC−CO2) from Garcinia indica kernels. SC−CO2 at 350 bar/60 °C/360 min gave maximum recovery of 90.24% compared to Soxhlet extraction with petroleum ether (428.6 g/kg). Hot water skimming of fat gave low recovery of 25.3% as against Soxhlet extraction. GC–MS analysis of fatty aci...
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Tuber aestivum is one of the most popular and delicious truffles in the world economic market and is reported to possess a wide range of biological activities. The total carbohydrate of this truffle constitutes about 5.65% w/w dry weight basis (dwb). The present work compares the yield of the polysaccharide obtained by conventional hot water extrac...
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Alcohol consumption often leads to hangover, a condition characterized by several symptoms, characteristically headache, nausea, fatigue and drowsiness. Hangover may be alleviated by altering the rate of alcohol metabolism and facilitating elimination of acetaldehyde by affecting the activity of alcohol dehydrogenase (ADH) and/or aldehyde dehydroge...
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Extracts of Curcuma aromatica Salisb rhizomes are traditionally used in the Indian sub-continent in herbal and cosmetic applications. Composition of extracts and their resulting bioactivities is dependent on the extraction technique. The present study compares yield, composition, and bioactivities of extract from C. aromatica by Soxhlet and supercr...
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Curcuma longa (CT) and Curcuma amada (MG) oleoresins were extracted using supercritical fluid extraction (SCF). SCF conditions were optimized for maximum extraction of oleoresin, curcuminoids, and total volatiles from CT at 350 bar/65 °C/150 min, and for maximum antioxidant and anti-inflammatory properties from MG at 300 bar/40 °C/30 min. Addition...
Article
Debittered bitter gourd juice was subjected to gamma irradiation doses of 0, 0.25, 0.5, 0.75, 1, 1.5 and 2.5 kGy and thermal pasteurization at temperatures of 65, 75, 85 and 95 °C. Shigella boydii was the most heat resistant pathogen tested (D10 of 42.8 s at 65 °C) while Bacillus cereus was the most resistant pathogen to irradiation with a D10 of 0...
Article
Acrylamide and polyacrylamide manufacturing/processing industries generate huge volume of waste containing acrylamide, an environmental pollutant (Group-2A carcinogen) that causes neurotoxicity, teratogenicity, mutagenicity, and reprotoxicity. Some bacteria produce acrylamidase and utilize acrylamide solely as carbon and nitrogen source for their g...
Article
Pea (Pisum sativum, L.) proteins (PP) were hydrophobically modified by N-substitutions with succinic anhydride (SA), n-octenyl succinic anhydride (OSA) and dodecenyl succinic anhydride (DDSA) to synthesize PP-SA, PP-OSA and PP-DDSA, respectively. The modification significantly changed the secondary structure, along with improvement in solubility, f...
Article
Premixes of kheer have huge demand in domestic as well as international market. Most available premixes are calorie-rich which limit their consumption by diabetics and health conscious consumers. The present work focused on developing low-energy kheer using extruded noodle grits pre-sweetened with three non-caloric sweeteners viz. aspartame, acesul...
Article
In the field of nanoecotoxicology, very few reports have focused on biochemical changes in non-target organisms after nanoexposure. A less explored aquatic non-target crustacean, Moina macrocopa, was used in the present study to analyze toxicity effects of gold nanoparticles (AuNPs), an emerging nanomaterial. AuNPs was fabricated using tannic acid...
Article
This paper reports on stabilization of serine cutinase activity by immobilizing it through cross linking with glutaraldehyde on magnetic nanoparticles (Fe-NPs) and intensification of catalytic activity by ultrasonic treatment. The optimum parameters were cross linking with 10.52 mM glutaraldehyde for 90 min using 1:2 (w/w) ratio of enzyme:Fe-NPs. T...
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Bioactives from plants are always in high demand in nutraceutical, pharmaceutical, and functional food sectors due to their health benefits. This intensifies the need of extraction of bioactives by different methods that can improve the yield and purity of the compound. Enzymes help in the release of bioactives from the plant material under optimiz...
Chapter
Immobilization of enzymes on matrices like iron oxide magnetic nanoparticles provides a new technique against the stagnant conventional approaches for stabilization of enzymes. Along with ease in synthesis and modification, the advantages of using these iron oxide nano-metallic matrices as enzyme support matrices are three dimensional viz. structur...
Article
The release of nanomaterials in water reservoirs is hazardous. Very few reports are available on the interaction of different sized nanoparticles with aquatic organisms and aquatic environment. In the present study, silver nanoparticles (AgNPs) having an average particle size of 20.80 ± 2.31 and 40.04 ± 4.72 nm were synthesized using polyvinylpyrro...
Article
Mango puree was produced out of Banaganappalli mango variety, a local species of mango grown in India. This puree was blended with starch, glycerol along with gelatin and defatted soy protein for casting the composite edible films. Utilization of excess mango available in high season, defatted soy protein from the waste of soy industry could help t...
Article
Acrylamidase from Cupriavidus oxalaticus ICTDB921 was immobilized on magnetic nanoparticles (MNPs) for degradation of acrylamide (a group 2A carcinogen and an environmental contaminant) from industrial waste water. Acrylamidase-MNPs were prepared (maximum recovery ~94%) at optimized process parameters viz. 1.5:1 (v/v) of acetone: crude acrylamidase...
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This study reports on removal of acrylamide from roasted coffee by acrylamidase from Cupriavidus oxalaticus ICTDB921. Chitosan coated calcium alginate beads were functionalized with citric acid as nontoxic cross linker and activated by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) (1.66:1 w/w) for...
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Triacontanol (TRIA) is a naturally synthesized non-conventional plant growth regulator (PGR) that can substitute synthetic PGRs, which are deleterious for human health and environment. TRIA was isolated from green tea leaves using Soxhlet and supercritical fluid extraction (SCF). Maximum extraction of 142 mg/kg (without alkali treatment) and 179 mg...
Article
The esterification of guar gum hydrolysate (GGH) by dodecenyl succinic anhydride (DDSA) was optimized to a degree of substitution (DS) of 0.029 by performing the reaction at 45 °C for 2 h using 3% DDSA (w/w basis of GGH) with added 0.5 g of NaHCO3. The GGH-DDSA ester formation was confirmed by FTIR. The emulsification and subsequent microencapsulat...
Article
A tri-enzyme mixture of cellulase, pectinase and xylanase present in fermentation broth of Aspergillus niger culture was directly recovered by solvent precipitation and co-immobilized on magnetic nanoparticles (MNPs) by cross linking with glutaraldehyde. A 2:1 ratio of isopropanol:total protein in the fermentation broth gave a precipitate with maxi...
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Truffles are symbiotic hypogeous edible fungi (form of mushroom) that form filamentous mycelia in their initial phase of the growth cycle as well as a symbiotic association with host plant roots. In the present study, Tuber maculatum mycelia were isolated and tested for extracellular amylase production at different pH on solid agar medium. Furtherm...
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Background: Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are becoming a major cause of chronic liver diseases globally. Polyunsaturated fatty acids (PUFA) have been postulated as a potential treatment for NAFLD. They can be obtained from diet and are also endogenously synthesized by enzymes delta-6-desaturase (D...
Article
Corn starch was oxidised using sodium hypochlorite to enhance its film forming property and reduce viscosity. This oxidised starch (OS) was further modified by n-octenyl succinic anhydride (OSA) to introduce hydrophobicity. This dual modified starch (OS-OSA) was characterized for crystalline and thermal attributes. The emulsion stability, viscosity...
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Puffed rice extrudates and rice noodles were chosen as vehicles for fortification of calcium using different salts, viz. calcium carbonate, calcium lysinate and tricalcium phosphate, at equivalent calcium concentration. The physiochemical properties, organoleptic acceptability and calcium bioaccessibility were studied for puffed rice extrudates bef...
Chapter
Although, polyamino acids are structurally similar to proteins, they are not proteins and do not have a specific sequence. Polyamino acids are polymerized from single amino acid that has molecular mass and polydispersity as similar as polysaccharides. Polyamino acid biosynthesis is considered to be an interesting example of biopolymer synthesis tha...
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Acrylamide is neurotoxic, genotoxic, teratogenic and carcinogenic. Its widespread use in various industrial processes leads to environmental contamination. Acrylamidase produced by certain bacteria degrade acrylamide to acrylic acid and ammonia. The present study details the isolation and identification of soil bacterium which could degrade acrylam...
Article
Hydrophobicity was introduced in the structure of guar gum (GG) by esterification with n-octenyl succinic anhydride (OSA), forming GG-OSA. This modification was evaluated by FTIR. Maximum degree of substitution of 0.025 was achieved by reacting GG with 0.4 mol OSA/mol of repeating unit of GG at 100 °C for 5 h using 0.5 equivalence of NaHCO3. This G...
Article
Ready-to-drink (RTD) ice tea is a ready prepared tea, produced from green and black tea originating from same plant Camellia sinensis. The objective of this study was to determine the effect of prebiotics [galacto-oligosaccharide (GOS), fructo-oligosaccharide (FOS), and inulin] or synbiotic ingredients (GOS, FOS, inulin, and Lactobacillus acidophil...
Chapter
Asparagus (Asparagus officinalis L.) can be white, purple, green, or a combination of purple and green. Each country grows specific types and varieties of asparagus suited to its particular climatic conditions and market needs. This chapter shows the top 10 asparagus producing countries in the world, as per Food and Agriculture Organization's (FAO'...
Chapter
This chapter reviews the production practices and consumption, postharvest physiology, storage and shelf-life, physicochemical and nutritional qualities, as well as the major value-added products made from broccoli and cauliflower. The combined production of broccoli and cauliflower in the world was about 24.2 million metric tons (MMT) in 2014. The...
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The present article describes extraction of chitosan from prawn shells waste and its application in thermal stabilization of Fusarium sp. ICT SAC1 cutinase by non-covalent and covalent conjugation. Extracted chitosan represented 78.40% degree of deacetylation (DDA), a molecular weight of 173 kDa and was soluble in 1% acetic acid with 2.8 ± 0.15% in...
Article
Pepper oleoresin was extracted using supercritical fluid extraction (SCF) from Piper nigrum berries. The conditions for maximum extraction of piperine were arrived at by calculating the solubility parameters of piperine and carbon dioxide using the Hildebrandt solubility equation. The effect of entrainers such as methanol, ethanol, and acetone was...
Article
The operational optimization of zeaxanthin production by Paracoccus zeaxanthinifaciens ATCC 21588 in a bubble column reactor was performed by coupling genetic algorithm (GA) to an artificial neural network (ANN) model developed using experimental one-variable-at-a-time (OVAT) results. The effects of varying air flow rate (2- 5 vvm) and inoculum siz...
Article
Proteins and polysaccharides are among the biopolymers produced by living organisms for their structural integrity, protection, physiological functions or as reserve energy. These biopolymers are extracted from their natural matrices by humans to fulfil basic as well as convenience needs. The inquisitive human nature, ever-growing demands and resou...
Article
Bitter gourd exhibits significant anti-diabetic activity. In the present study, pectinase concentration (4.04–15.92 ml kg⁻¹), incubation time (48–191 min) and temperature (31–55 °C) were optimized using response surface methodology (RSM) for obtaining increased juice yield with higher anti-diabetic (α-amylase and α-glucosidase inhibition) activity,...
Article
Truffles are edible fungi that grow symbiotically with several trees. In this study, Tuber maculatum mycelia were isolated and screen qualitatively for extracellular xylanase production at a broad pH range (4.0, 7.0 and 9.0) in agar plates. Based on zone of clearance highest xylanase activity was observed at pH 7.0. Furthermore, T. maculatum myceli...
Article
Germination of fenugreek seed showed better nutraceutical profile as evaluated by in vivo (oral glucose tolerance and acute antihypertriglyceridemic tests) on rats and in vitro DPPH and enzyme inhibition assays (α‐glucosidase, lipase, and lipoxygenase). Attempts were made to develop debittered and germinated fenugreek seed flour (DGFSF) by soaking...
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Full-text available
Although acrylamide finds diverse industrial applications, its presence in the environment is hazardous due to its carcinogenic, neurotoxic, and teratogenic properties. In spite of the general toxicity of acrylamide in the monomer form, some microorganisms are able to use it as a source of energy by catabolizing it to ammonia and acrylic acid by me...
Article
Polymorphisms in bitter taste receptor gene TAS2R38 alter the ability to sense the intensity of bitterness of phenylthiocarbamide (PTC) and 6-n-propylthiouracil (PROP). Genetic variation in sensitivity towards PTC and PROP may affect food preferences and susceptibility to certain diseases. This is the first study aimed at investigating frequency an...
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Full-text available
Flaxseed has gained significant interest as a source of edible oil that is rich in omega-3 fatty acids, high content of flaxseed proteins and lignans that are known to be therapeutic. Low oxidative stability of flaxseed oil necessitates the use of extraction technologies that are advanced and economically viable than the currently used cold press e...
Chapter
The use of enzymes in food, pharmaceutical, and other industries has long been recognized for its effectiveness, both technologically and economically. It encompasses to achieve high product yields, reduce by-product formation, and avoid severe operational conditions. Hence, enzymes are also being used in the extraction of important bioactive compo...
Article
Cutinase, a member of α/β-fold hydrolase family possess potentially diverse applications in several industrial processes and products. The present work aims towards thermo-stabilization of cutinase from novel source Fusarium sp. ICT SAC1 via non-covalent interaction with polysaccharides. Although all six polysaccharides chosen for study enhanced th...
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Full-text available
Interaction of truffle mycelium with the host plant involves the excretion of extracellular enzymes. The ability of Tuber maculatum mycelium to produce an extracellular cellulase during submerged fermentation was demonstrated for the first time. T. maculatum mycelia were isolated and tested for extracellular cellulase production at variable pH on s...