Asir Gani

Effect of γ-irradiation on structure and nutraceutical potential of β-D-glucan from barley (Hordeum vulgare).

This paper reports the characterization and potential antioxidant activity of β-D-glucan isolated from barley treated with γ-rays. The β-D-glucan was irradiated with 0, 2, 4 and 8 kGy by gamma ray. The samples were characterized by Fourier transform-infrared spectroscopy, gel permeation chromatography (GPC) and quantitative estimation by Megazyme β-D-glucan assay kit. The average molecular weight of non-irradiated β-D-glucan was 177 kDa that decreased to 79 kDa at 8 kGy. Antioxidant activity was evaluated by five complementary assays including DPPH, lipid peroxidation, reducing power, metal chelating ability and oxidative DNA damage assays. Further, the antiproliferative potential of irradiated β-D-glucan was tested against three human cancer cell lines including Colo-205, T47D and MCF7 using MTT assay. Irradiated β-D-glucan exhibited dose dependent cancer cell growth inhibition. In conclusion, the present study demonstrates that irradiation leads to the formation of low molecular weight β-D-glucan with enhanced antioxidant and antiproliferative activities.

DNA scission inhibition, antioxidant, and antiproliferative activities of water chestnut (Trapa natans) extracted in different solvents

This investigation deals with the study of polyphenolic, antioxidant, and antiproliferative activities of water chestnut extracted in different solvents. The antioxidant activities of the extract in different solvents were the maximum in methanol, followed by ethanol and aqueous solution and were found to be 39.8%, 34.1% and 32.6% from DPPH assay, and 45.64%, 35.08% and 30.52% from lipid peroxidation assay, respectively, whereas the reducing power inhibition assay showed the maximum antioxidant potential in the aqueous extract of the sample, followed by methanolic and ethanolic extracts. The polyphenolic content of the water chestnut was found to be more in methanol than in aqueous and ethanolic extracts. The water chestnut extract also showed the antiproliferative potential when tested against the human colon cancer cell line (Colo-205), human ductal breast epithelial tumor cell line (T47D), and human breast adenocarcinoma cell line (MCF7). It also showed some protection from DNA damage induced by hydroxyl radicals in calf thymus DNA.

Germination and microwave processing of barley (Hordeum vulgare L) changes the structural and physicochemical properties of β-d-glucan & enhances its antioxidant potential

The nutraceutical potential of β-d-glucan is largely dependent on its structure, size and viscosity. The present study analyzed the effect of germination and microwave processing of barley on the structural, size, antioxidant and thermal characteristics of β-d-glucan. The molecular weight and viscosity of β-d-glucan obtained from germinated barley (GGB) were the lowest (144kDa and 37.33cp) as compared to β-d-glucan from microwave processed barley (GMB) and unprocessed barley (GUB). The GGB exhibited higher antioxidant potential than GMB and GUB. The Structural elucidation by ATR-FTIR revealed scission in polymeric chain and β glycosydic linkage of β-d-glucan obtained from processed barley. The highest peak intensity at glycosydic linkage in GGB confirms more scission in the molecule. The DSC curve of GGB showed the highest transition temperature. It was concluded that germination of barley can be a good approach for enhancing the antioxidant potential of β-d-glucan.

Nutraceutical properties of the green tea polyphenols.

Green tea is manufactured from the leaves of the plant Camellia sinensis and has been regarded to possess anti-cancer, anti-obesity, anti-atherosclerotic, antidiabetic and antimicrobial effects. The main bioactive components present in green tea are polysaccharides, flavonoids, vitamins B, catechin compounds, fluoride and etc. Among them catechin compounds have been proven to have a variety of physiological functions. Due to the popularity of the health benefits of tea catechins, new products have been developed with tea as an active ingredient such as ready-to-drink (RTD) tea beverages, confections, ice creams, cereal bars and pet foods. This review summarizes several lines of evidence to indicate the health-promoting properties of green tea and their potential to be used in development of foods with added nutraceutical value.

Production of RS4 from rice starch and its utilization as an encapsulating agent for targeted delivery of probiotics

The research reported in this article is based on the hypothesis that crosslinking of starch can make it a potential wall material for targeted delivery of probiotics by altering its digestion. Three probiotic strains namely Lactobacillus casei, Lactobacillus brevis and Lactobacillus plantarum were microencapsulated with resistant starch. Encapsulation yield (%) of resistant starch microspheres was in the range of 43.01-48.46. The average diameter of resistant starch microparticles was in the range of 45.53-49.29μm. Fourier transform infrared (FT-IR) spectroscopy of microcapsules showed peaks in the region of 900-1300cm-1 and 2918-2925cm-1 which corresponds to the presence of bacteria. Differential Scanning Calorimeter (DSC) showed better thermal stability of resistant starch microcapsules. Microencapsulated probiotics survived well in simulated gastrointestinal conditions and adverse heat conditions. The viability of the microcapsulated lactobacilli also remained high (>7 log cfu g-1) for 2months at 4°C. The results revealed that resistant starch is the potential new delivery carrier for oral administration of probiotics.

Structural, thermal, functional, antioxidant & antimicrobial properties of β-d-glucan extracted from baker's yeast (Saccharomyces cereviseae)-Effect of γ-irradiation.

This study was carried out to evaluate the effect of γ-irradiation (0, 5, 10, 20, 30 & 50kGy) on the structural, functional, antioxidant and antimicrobial properties of yeast β-d-glucan. The samples were characterized by ATR-FTIR, gel permeation chromatography (GPC) and the thermal properties were studied using DSC. There was a decrease in the average molecular weight of β-d-glucan as the irradiation dose increased. The functional properties of irradiated yeast β-d-glucan were largely influenced by the action of gamma radiation like swelling power and viscosity decreases with increase in the irradiation dose while as fat binding capacity, emulsifying properties, foaming properties and bile acid binding capacity shows an increasing trend. All the antioxidant properties carried out using six different assays increased significantly (p≤0.05) in a dose dependent manner. The antibacterial activity of yeast β-d-glucan also showed an increasing trend with increase in the irradiation dose from 5 to 50kDa.

Effect of extraction time on antioxidants and bioactive volatile components of green tea (Camellia sinensis), using GC/MS

Abstract Two green tea types, leaf grade and sanding, were extracted at different time intervals: 20, 40, and 120 min at a constant temperature of 50°C. The extracts were analyzed by GC/MS technique. The major compounds identified were myristic acid, palmitic acid, stearic acid, oleic acid, 1H-purine-2,6-dione, caffeine, linoleic acid, diethyl ester, and 1H-purine-6-amine. Stearic acid, palmitic acid, linoleic acid, and myristic acid were more abundantly present in the leaf-grade variety than sanding. However, some levels of acetic acid, cyclobutanol, hexadecanoic acid, octadecanoic acid, 9-octadecenoic acid, and caffeine were also found in both the tea types. Most of the volatile compounds were detected between 20–40-min time of extraction. The 40-min time of extraction also showed the maximum content of polyphenols and antioxidants in both the tea types. Thus, 40 min was suggested as the most suitable time for maximum extraction of bioactive volatiles, antioxidants, and polyphenols from green tea.

A review of the recent advances in starch as active and nanocomposite packaging films

Abstract Technological advances have led to increased constraints regarding food packaging due to environmental issues, consumer health concerns, and economic restrictions associated therewith. Hence, food scientists and technologists are now more focused on developing biopolymer packages. Starch satisfies all the principle aspects, making it a promising raw material for edible coatings/films. Starch as a package material has grabbed much attention both at academic as well as industrial levels. Besides this, the role of various plasticizers, polys, sugars, and wetting agents are discussed and their importance in packaging industries. Herein, the role of starch as packaging material and nanofillers/composites is discussed in detail. The review summons a comprehensive and current overview of the widely available information and recent advances in starch film packaging.

Effect of virgin coconut oil on properties of surimi gel

Effects of virgin coconut oil (VCO) at various levels (0–25%) on the properties of croaker surimi gels were studied. As the levels of VCO increased up to 15%, breaking force continuously decreased. No differences in breaking force, deformation and fracture constant were noticeable when VCO of 15–25% was incorporated. Based on texture profile analysis, hardness and chewiness decreased as the level of added VCO increased up to 10%, while no marked changes were observed with the addition of 10–25% VCO. Addition of VCO had no profound impact on springiness, cohesiveness and resilience. No remarkable change in protein pattern among all surimi gel samples was noticed, regardless of VCO levels. Lower elastic (G′) as well as loss moduli (G″) of surimi paste were observed when VCO was added, compared to the control. Nevertheless, there was no marked difference in the moduli among samples containing VCO at all levels. Whiteness of surimi gel increased, whereas expressible moisture content decreased as VCO levels increased. Microstructure study revealed that VCO droplets were distributed uniformly in gel network. Overall likeness of surimi gel was also increased for gel added with VCO. Therefore, VCO addition directly affected textural properties and improved the whiteness as well as sensory property of surimi gel.

Microencapsulation of saffron anthocyanins using β glucan and β cyclodextrin: Microcapsule characterization, release behaviour & antioxidant potential during in-vitro digestion

In the present study, the saffron anthocyanins were encapsulated in β-glucan and β-cyclodextrin by spray drying technique to achieve their stability under adverse gastro-environmental conditions. The microcapsules were subjected to simulated gastric conditions and release behavior of monomeric anthocyanins, antioxidants and phenols were studied. The structural properties of microcapsules were analyzed by SEM and ATR-FTIR spectroscopy. The particle size distribution, density, color, encapsulation efficiency and powder yield of samples were also evaluated. A characteristic band at 1700 cm-1 by FTIR and specific enclosed particles in the cavities of wall material were observed from the micrographs of SEM that confirmed the incorporation of anthocyanins in the microcapsules. The higher content of anthocyanins, antioxidants and phenols in the intestinal conditions revealed the protection of core material from adverse conditions of stomach by encapsulation. Further studies are suggested to investigate the stability of encapsulated anthocyanins in different environmental and processing conditions.