Effect of different pretreatments on antioxidant activity of oats grown in the Himalayan region.

In this work the different varieties of oats were subjected to three pre-treatments such as germination, sand roasting and γ-irradiation. The pretreated oat grains were evaluated for phenolic content, flavonoid content and antioxidant activity. RP-HPLC displayed that the amount of ferulic acid, chlorogenic acid, kaempferol, ellagic acid and epicatechin in native, roasted and γ-irradiated oats varied in the range of 2.51-3.23, 0.97-1.89, 4.35-5.33, 1.56-2.197 and 3.387-10.8 µg/100 g, respectively. Total phenolic content (TPC) expressed as µg GAE/g and µg FAE/g and total flavonoid content (TFC) expressed as µg rutin equivalent/g was found highest in germinated samples. Study reported increase in antioxidant activity in the following order; γ-irradiation > germination > roasting > native. It was concluded that the different pretreatments enhanced antioxidant properties of the oat grains therefore can be efficiently utilized as food or functional ingredient in various food systems.

Nano reduction coupled with encapsulation as a novel technique for utilising millet proteins as future foods.

Crocin (saffron bioactive) loaded protein nanoparticles were prepared from three underutilised cereal varieties viz., sorghum (SPCN), foxtail millet (FPCN) and pearl millet (PPCN) using ultrasonication technique. The particle size of crocin loaded protein complex was attained in the nano range with reduced polydispersity index and negative zeta potential. The encapsulation efficiency of crocin in protein nanoparticles was found to be 83.78% (FPCN), 78.74 % (SPCN) and 70.01% (PPCN). The topographical images of crocin loaded protein nano complex was revealed using field emission-scanning electron microscopy (FE-SEM). The attenuated total reflectance fourier transform infra-spectroscopy (ATR-FTIR) analysis showed the characteristic peaks of crocin at 956, 1700 and 3350 cm-1 in protein-crocin nanocomplex as a confirmatory test for nanoencapsulation. The antimicrobial activity of crocin loaded protein nanocomplex against three strains (Escherichia coli, Staphylococcus aureus and Fusarium oxysporium) were also evaluated. In vitro release studies showed higher content of crocin released in simulated intestinal conditions ensuring its controlled release at target site. Bioactivity (anti-cancerous and anti-hypertensive) of crocin upon in-vitro digestion were well retained indicating that protein nanoparticles can act as an effective wall material. Our results suggest that protein nanoparticles prepared in this study can act as an effective oral delivery vehicle for crocin that could be used for development of functional foods.

Resistant starch from five Himalayan rice cultivars and Horse chestnut: Extraction method optimization and characterization.

In this study resistant starch (RS) was extracted from five Himalayan rice cultivars and Indian Horse chestnut (HCN) using porcine pancreatin enzyme following which it was subsequently characterized for its physicochemical, structural and functional properties. In vitro digestibility test showed that RS content of the rice cultivars and HCN was in the range of 85.5 to 99.5%. The RS extracted from the rice cultivars and HCN showed significant difference in the apparent amylose content (AAC), ranging between 31.83 to 40.68% for rice and 45.79% for HCN. Water absorption capacity (WAC), swelling and solubility index of RS ranged from 112-133.9%, 5.28-7.25 g/g and 0.033-0.044 g/g, respectively. The rice RS granules were polyhedral and irregular shaped with granular length in the range of 4.8-5.9 µm. The HCN RS granule morphology showed smooth surfaced, round, elliptical, irregular and oval shapes with average granular length of 21 µm. Pasting behavior also varied significantly between rice RS and HCN RS with later showing the lower values of pasting properties. Thermal properties (T0, Tp, Tc) and ΔH gel also varied considerably between the rice RS and HCN RS, wherein the highest values for peak gelatinization temperature and gelatinization enthalpy were seen for CH-1039. X-ray diffraction pattern of rice RS and HCN RS showed the characteristic A type of pattern in consonance with cereal starches.

Water extractable pentosans - Quantification of ferulic acid using RP-HPLC, techno-rheological and antioxidant properties.

Water extractable pentosans extracted from three varieties of oats were studied for structural analysis using ATR- FTIR, ferulic acid content using RP-HPLC, antioxidant activity by DPPH, reducing power, and metal chelating assays, and functional properties. The appearance of absorption band at 1720 cm-1 in water extractable pentosans is assigned to the presence of aromatic esters as displayed from ATR-FTIR spectrum. All the samples exhibited non-newtonian behavior with viscosities following the order; SWEP > 20WEP > 90WEP. Bile acid binding capacity of water soluble pentosans varied significantly from 46.69 to 49.40%. RP-HPLC displayed that water extractable pentosans from SKO20 contained about 2 times higher FA (423.00 µg/100 g) compared to SWEP (250.00 µg/100 g) and 90 WEP (253.00 µg/100 g). Water soluble pentosans had DPPH scavenging activity, reducing power, and metal chelation activity in the range of 13.57-17.45 (µg α-tocopherol/g), 8.91-10.24 (µg BHT/g), and 0.55-0.76 (µg citric acid/g), respectively.

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.

ß-d-glucan as an enteric delivery vehicle for probiotics.

Three strains of probiotics L. casei, L. acidophilus and B. bifidum were encapsulated in ß-d-glucan matrix using freeze drying technique in order to increase survivability during their journey through GI tract. The encapsulation efficiency (%) of ß-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 ß-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 ß-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.

Physicochemical properties, in-vitro digestibility and structural elucidation of RS4 from rice starch.

Starches extracted from four different rice cultivars were phosphorylated by using STMP/STPP to make modified food starches with high contents of type 4 resistant starch (RS4). The results revealed 10- fold improvement in RS4 content by the phosphorylation of starch. The phosphorus % and DS values of rice starches ranged from 0.33 to 0.35, and 0.016 to 0.018, respectively. FT-IR spectroscopy showed reduction of OH stretching band at 3290cm-1 and the appearance of PO at 1244-1266cm-1 which confirms crosslinking of starch with STMP/STPP. Phosphorylation was found to increase water absorption capacity, oil absorption capacity, bile-acid binding and lightness, whereas amylose content, swelling power, solubility index and light transmittance were decreased with phosphorylation. DSC analyses revealed increase in thermal transition temperatures of the crosslinked starches which suggests that the application of STMP/STPP as a crosslinker can improve the integrality and stability of starch. SEM micro-graphs revealed that phosphorylated rice starch granules retained their integrity, while some fissures appeared on the surface of some granules. XRD analysis revealed decreased crystallinity of RS4 rice starches.

Physico-chemical, rheological and antioxidant properties of sweet chestnut (Castanea sativa Mill.) as affected by pan and microwave roasting.

Sweet chestnut (Castanea sativa Mill.) belongs to the family Fagaceae and sub family Castaneoideae. Bioactive components such as tannins are present in sweet chestnut in high proportion giving astringent bitter taste and reducing their palatability. Roasting reduces the anti-nutritional factors in chestnut. This study was conducted to compare the effects of pan and microwave roasting on physicochemical, functional, rheological and antioxidant properties of sweet chestnut. Antioxidant activity was determined using DPPH inhibition activity, reducing power, and total phenolic content. Structural analysis was carried out using FT-IR analysis. Protein, fat, and ash contents displayed insignificant (P > 0.05) variations. "L" value decreased from 90.66 to 81.43, whereas, "a" and "b" values increased from 0.02 to 0.90 and 11.99 to 20.5, respectively, upon roasting. Significant (P < 0.05) increase in water absorption capacity (1.32-3.39 g/g), oil absorption capacity (1.22-1.63 g/g), and antioxidant properties was observed following roasting. Flour obtained from roasted chestnuts exhibited a significant decrease in light transmittance, foaming, and pasting properties. Higher gelatinization temperatures and lower enthalpies were reported in microwave and pan roasted chestnut flours. Roasting also reduced the viscoelastic behavior of native sweet chestnut and changed the transmittance of identical functional groups as revealed by FT-IR analysis.

γ-Irradiation of oat grain - Effect on physico-chemical, structural, thermal, and antioxidant properties of extracted starch.

Three different varieties of oat grains, Sabzaar, SKO-20, SKO-90 maintained at the moisture level of 12% were γ-irradiated at four different dosage levels - 5, 10, 15, and 20kGy. Starch was extracted and its physicochemical, structural, thermal, and antioxidant properties were studied. Amongst the physico-chemical properties, syneresis, solubility index, swelling index and light transmittance values showed a varied significance from their native counterparts. Irradiation also had an effect on RVA profiles which exhibited a decrease in peak, trough, final and set back viscosities whereas the pasting temperatures showed a significant (P≤0.05) decline. The exposure of hydroxyl groups in starch chain due to irradiation was confirmed via ATR FT-IR. γ-Irradiation resulted in the formation of ridges on the surface of starch as revealed from SEM. Irradiation resulted in a significant improvement in antioxidant activity of the extracted starches.

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.

Geometrical, functional, thermal, and structural properties of oat varieties from temperate region of India.

Geometrical, functional, thermal properties and FTIR analysis of three varieties of oat flour (Sabzaar, SKO20, & SKO90) were investigated. Sabzaar showed highest thickness, geometric mean diameter, arthimetic mean diameter, sphericity and grain volume. The density of oat grains varied from 0.393 to 0.37 g/mL (bulk) and 1.2 to 1.8 g/mL (true). WAC showed significant (P < 0.05) difference among the cultivars with Sabzaar flour showing the highest value (2.36 g/g) and SKO20 (1.98 g/g) the lowest. Peak viscosity of oat flours was in the range of 460.33-489.33 cP. Flour samples showed the presence of small as well as large starch granules, oval or irregular shape with a smooth surface having some dents or fissures and some damaged starch and with varying dimensions. Average granule size of oat starch samples was within the range of 1.5-6.6 µm in Sabzaar, 1.1-5.2 µm in SKO20, and 1.7-6.8 µm in SKO90. The gelatinization transition temperatures onset temperature (To), peak temperature (Tp), and conclusion temperature (Tc) varied significantly (p < 0.05) among three varieties.

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, 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.

ß-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 ß-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 ß-glucan-probiotic beads was found to be 74.01%. The surface morphology of ß-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 ß-glucan was evaluated using Differential Scanning Calorimeter. The efficiency of ß-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.

Enzymatic hydrolysis of whey and casein protein- effect on functional, rheological, textural and sensory properties of breads.

Milk proteins were hydrolyzed by papain and their effect on the rheological, textural and sensory properties of bread were investigated. Water absorption capacity, emulsification capacity, foam volume, foam stability and solubility of Whey and casein protein concentrates and their hydrolysates were determined. The farinograph parameters of wheat flour and blends of wheat flour with casein and whey protein and their hydrolysates were determined to evaluate changes in water absorption capacity, dough development time, dough stability time and mixing tolerance index. The incorporation of WPC, casein and their hydrolysates up to the level of 5 % showed dough properties comparable to control. It was also found that 5 % level incorporation of milk proteins and their hydrolysates have no drastic effect on physical and sensory attributes of bread. The pasting properties showed significant decrease (p ≤ 0.05) when compared with wheat flour at all levels of addition of whey and casein protein concentrates and hydrolysates. Scanning electron microscopy of bread samples shows disruption in the well-defined protein - starch complex of wheat flour bread and the structure of gluten was weak as the concentration of whey protein increases in the wheat flour bread.

Effect of whey and casein protein hydrolysates on rheological, textural and sensory properties of cookies.

Milk proteins were hydrolyzed by papain and their effect on the rheological, textural and sensory properties of cookies were investigated. Water absorption (%) decreased significantly as the amount of milk protein concentrates and hydrolysates increased up to a level of 15 % in the wheat flour. Dough extensibility decreased with inrease in parental proteins and their hydrolysates in wheat flour, significantly. Similarly, the pasting properties also varied significantly in direct proportion to the quantity added in the wheat flour. The colour difference (ΔE) of cookies supplemented with milk protein concentrates and hydrolysates were significantly higher than cookies prepared from control. Physical and sensory characteristics of cookies at 5 % level of supplementation were found to be acceptable. Also the scores assigned by the judges for texture and colour were in good agreement with the measurements derived from the physical tests.

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

This paper reports the characterization and potential antioxidant activity of ß-D-glucan isolated from barley treated with γ-rays. The ß-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 ß-D-glucan assay kit. The average molecular weight of non-irradiated ß-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 ß-D-glucan was tested against three human cancer cell lines including Colo-205, T47D and MCF7 using MTT assay. Irradiated ß-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 ß-D-glucan with enhanced antioxidant and antiproliferative activities.