Bilal Ahmad Ashwar

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.

β-Glucan as an encapsulating agent: Effect on probiotic survival in simulated gastrointestinal tract

Three strains of probiotics Lactobacillus casei, Lactobacillus brevis, and Lactobacillus plantarum were encapsulated in β-glucan matrix using emulsion technique. Further the encapsulated cells were studied for their tolerance in simulated gastrointestinal conditions and its storage stability. The average encapsulation efficiency of β-glucan-probiotic beads was found to be 74.01%. The surface morphology of β-glucan containing bacteria was studied using SEM. The noteworthy absorptions in the FT-IR spectra between 1300-900 cm(-1) and 2918-2925 cm(-1) corresponds to the presence of bacteria into the glucan matrix. Also, the thermal stability of β-glucan was evaluated using Differential Scanning Calorimeter. The efficiency of β-glucan in protecting the surviability of probiotic cells under simulated gastrointestinal conditions was studied. Results revealed significant (p<0.05) improvement to tolerance when the encapsulated cells were subjected to stresses like low pH, heat treatment, simulated intestinal conditions and storage.

Effect of infrared and microwave radiations on properties of Indian Horse Chestnut starch

Starch extracted from Indian Horse Chestnut (IHCN) was subjected to infrared and microwave radiations for different time intervals (15 s, 30 s, & 45 s) at constant dose. The structural change of MW and IR radiated IHCN starches were determined by Fourier transform-infra red spectroscopy. The increased peak intensity at 3240 cm(-1) of treated starch represents more exposure of hydroxyl groups due to radiation. Granule morphology of native starch showed round and elliptical granules with smooth surfaces. However radiation treatment resulted in the development of surface cracks. Effect of radiation on physicochemical properties of starch revealed increase in water absorption capacity and light transmittance and decrease in apparent amylose content, pH, and syneresis. The peak, trough, final, and setback viscosities were significantly reduced with increase in treatment time. Radiated starches displayed significantly lower values of To,Tp, and ΔHgel than native starch. Further antioxidant activities were evaluated by DPPH and FRAP assays. Results showed significant improvement in antioxidant activity of starch by both MW and IR treatments.

In-vitro digestibility, rheology, structure, and functionality of RS3 from oat starch.

Starches isolated from three different varieties of oat were modified with dual autoclaving-retrogradation treatment to make modified food starches with high contents of type 3 resistant starch (RS3). FT-IR spectroscopy showed increase in the ratio of intensity of 1047cm(-1)/1022cm(-1) on treatment. Morphology of the oat starches changed into a continuous network with increased values for onset temperature (To), peak temperature (Tp), and conclusion temperature (Tc). XRD showed an additional peak at 13° and increase in peak intensity at 20° inclusive of the major X-ray diffraction peaks which reflects formation of amylose-lipid complex from dual autoclaving-retrogradation cycle. Peaks at 13° and 20° are the typical peaks of the V-type pattern. Rheological analysis suggested that retrogradated oat starches showed shear thickening behavior as revealed from Herschel-Bulkely model and frequency sweep.

Physico-chemical, structural, pasting and thermal properties of starches of fourteen Himalayan rice cultivars.

Starch of fourteen rice cultivars grown in Himalayan region were evaluated for physico-chemical, structural, pasting and thermal properties. The rice cultivars selected showed a wide variation in apparent amylose content (AAC), ranging between 10.76%-26.87%, highest in CH-1039 and lowest in SKAU-292 starch. There were ten low, three intermediate and one high AAC rice. Resistant starch content varied significantly among the rice cultivars, ranging from 6.00% to 19.60%. Generally, high ACC starches presented high contents of resistant starch. Water absorption capacity (80.10-130.32%), swelling (5.73-9.61g/g) and solubility (0.037-0.090g/g) indices varied significantly among the rice cultivars. The rice starch granule morphology showed polyhedral or irregular shapes and granular sizes in the range of 1.8-6.7μm in different rice starches. Pasting profile of starch varied significantly among the rice cultivars, probably due to variations in their AAC. Thermal properties of the starches ranged considerably among different rice cultivars: onset temperature of gelatinization, To (58.25-72.49°C), peak temperature of gelatinization, Tp (69.93-93.26°C), conclusion temperature of gelatinization, Tc (97.28±8.28-112.16°C) and gelatinization enthalpy ΔHG (14.29-29.63J/g). The ATR-FTIR spectroscopy of rice starches identified most of the α-1→4 glucosidic linkages within the absorption bands of 1149-1023cm-1.

Physico-chemical, functional and structural properties of RS3/RS4 from kidney bean (Phaseolus vulgaris) cultivars

Starch isolated from four kidney bean cultivars (Yellow bean, Red bean, Black bean and White bean) were physically and chemically modified in order to prepare resistant starch (RS3/RS4). Following the Heat-moisture treatment (HMT) and Citric acid modification (CT) of the native starch, the amylose content got decreased whereas bulk and tapped density (g/ml) increased. Both HMT and CT reduced the swelling power and the solubility of native starch. Pasting temperature increased and peak, breakdown, final, and set-back viscosity decreased after both the modifications. Fourier Transform Infrared Spectroscopy (FTIR) analysis displayed peaks at 1020cm(-1) in HMT and 1724cm(-1) in CT starches. Differential Scanning Calorimetry (DSC) analysis revealed that samples were more stable after modification. X-ray diffraction (XRD) analysis revealed reordering of chain segments to more crystalline structure. These results suggested modifications resulted in starch with improved properties and could be a possible method for the RS preparation with better thermal stability.

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.

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.

Dual enzyme modified oat starch: Structural characterisation, rheological properties, and digestibility in simulated GI tract

Oat starches from three different varieties were treated with combination of β-amylase and transglucosidase and their structural, rheological, thermal, and digestibility through simulated GI tract conditions were investigated. By dual enzyme modification, the granules form a discontinuous compact fibrous structure with many surface cracks. The transformation from A-type to A+V type pattern with decrease in crystallinity was observed in dual enzyme modified starches. The ratio of intensity, 1047/1022cm-1 and 995/1022cm-1 of enzyme modified starches were reduced compared to their native ones as revealed from FTIR spectra. The resistant starch (RS3) content was increased to 35.81-48.88% from 17.14-23.9%. The viscosity of starches decreased on enzymatic treatment, exhibited shear-thinning behavior as reflected from the convex shaped graph. Also, dual enzyme treatment of starches resulted in significant decrease in amount of glucose release for Sabzaar than SKO20 and SKO90. The increase of RS observed in this study is associated with enhanced branch density and RS3 crystallites.

β-d-glucan as an enteric delivery vehicle for probiotics

Three strains of probiotics L. casei, L. acidophilus and B. bifidum were encapsulated in β-d-glucan matrix using freeze drying technique in order to increase survivability during their journey through GI tract. The encapsulation efficiency (%) of β-d-glucan varied significantly with Bifidobacteria showing low survival rate than Lactobacilli. SEM images revealed a partially collapsed structure with bacterial cells distributed randomly in the matrix. Further absorption band between 1300 and 900cm-1 in FTIR spectra shows the presence of bacterial proteins and nucleic acids. For encapsulated β-d-glucan maximum degree of swelling was observed at pH 3 and 4, whereas when the pH value was increased to 6.5 the encapsulated β-d-glucan started their disintegration. In vitro release studies revealed that the microcapsules start to dissolve upon entry to the small intestine where it is needed most.