Sukhcharn Singh

Effect of Pretreatments on Drying and Rehydration Kinetics and Color of Sweet Potato Slices

The effect of air temperature and pretreatments (KMS: citric acid) on drying kinetics of sweet potato slices was investigated. Drying experiments were performed in a tray dryer. In falling rate period, moisture transfer from sweet potato slices was described by applying the unsteady-state Fickian diffusion model, and the rate constant (k) were calculated. The effect of temperature on k could be interpreted according to Arrhenius law. Drying rate and therefore k values were found to be affected by pretreatments. Rehydration rates of dried sweet potato slices at 25, 40, 80°C were also determined and found to be independent of drying conditions and rehydration temperature. The ΔE value was found to be the highest for slices treated at 50°C with 0.5:1.0% KMS and citric acid.

Structural, thermal and rheological properties of starches isolated from Indian quinoa varieties

In this study starches isolated from Indian quinoa varieties were examined for physicochemical, morphological, thermal and rheological properties. Among isolated starches V1 showed higher starch yield and lower purity (48.45% and 98.32%) than V2 (41.28 and 98.53%). The amylose content was higher for V1 (12.10%) than V2 (9.46%). Swelling powers and solubility of the starches increased with increasing temperature. Peak viscosity (386.4 RVU) was higher for V1. In contrast V2 showed higher pasting temperature (72.85°C). Low setback viscosity of the starches suggests that they can be profitably used in frozen and refrigerated foods. Starch granules from both varieties were irregular, angular and polygonal in shape. The starch granule size obtained by SEM was 1.23μm for V1 and 1.19μm for V2. Both starches showed a typical A-type diffractrometric pattern with varying crystallinity. Further V1 showed lower transition temperatures (To, Tp and Tc) than V2. FTIR spectroscopy showed higher intensity and broader shape of V2 at OH stretch which can be due to its higher crystallinity. Increased interest is shown in quinoa starch because of its unique microcrystalline granules. Higher yield and purity values suggest that both varieties can be exploited for commercial starch utilization.

Physical, textural, and sensory characteristics of wheat and amaranth flour blend cookies

Abstract This study examined the effects of whole amaranth substitutions at various proportions and evaluated the cookies baking behavior. Six types of formulations of cookies were prepared with whole amaranth flour ranging from 20, 40, 60, 80, and 100%. These cookies were evaluated for physical (thickness, diameter, spread ratio, and bake loss), textural, and organoleptic attributes. The diameter and spread ratios were found to be higher in whole amaranth flour cookies 52.20 mm and 6.46, respectively, as compared to other blends (20–80%) of cookies from 51.37 to 51.92 mm and 6.13 to 6.36, respectively. Textural measurement showed that hardness of cookies decreased with the addition of amaranth flour. Whole amaranth flour cookies required least snap force (72.4 N) compared to control (whole-wheat flour) cookies (145 N). Sensory data indicated that the amaranth cookies with up to 60% were acceptable, while additional amaranth flour resulted in a decreased mean score for overall acceptability.

Effect of storage conditions and packaging materials on the quality attributes of gluten-free extrudates and cookies made from germinated chenopodium (Chenopodium album) flour

This study evaluated the effect of storage and packaging materials on the quality attributes of germinated C. album flour extrudates and cookies. For the storage studies of the extrudates low density polyethylene (LDPE) and laminated pouches (LP) of polyester-aluminium-polypropylene (PE-AL-PP) and for cookies LDPE and LP of metalized polyester polyethylene (MET-PPE)were used at ambient temperature (25 ± 2 °C). Quality parameters like moisture content, water activity, free fatty acids, peroxide value, bulk density, color, hardness, microbial and sensory analysis of developed products were evaluated at an interval of 15 days during 4 months of storage period. Higher quality changes were observed in extrudates and cookies packed in LDPE than in LP and MET-PPE. The overall acceptability data showed higher decrease in the sensory scores of extrudates and cookies packed in LDPE (7.9–5.5 for extrudates and 7.75–5 in cookies) as compared to LP (7.9–6.12 for extrudates) and MET-PPE (7.75–6.10 for cookies) packages. From the above study and results, it is suggested that the LP for extrudate and MET-PPE in cookies can be used for their storage upto 4 months at ambient conditions.

Physico-chemical and textural property of starch isolated from Chenopodium (Chenopodium album) grains

Abstract The aim of current study was to isolate and evaluate the starch from Chenopodium album (LP) and Chenopodium album (LS) varieties for its physicochemical, particle size analysis, and textural properties. The starch isolated from C. album (LP) and C. album (LS) showed yield values of 37.59 and 47.30%, while amylose content of the mentioned varieties was found to be 16.75 and 19.11%, respectively. The starch from C. album (LS) showed higher values of water and oil binding capacities (178 and 225%, respectively), while as the corresponding values for C. album (LP) were found to be 169.5 and 222%. Laser diffraction particle size analysis showed unimodal particle size distribution profile with mean particle diameters of 10.52 and 10.64 μm for C. album (LP) and C. album (LS) starches, respectively. The granular size and shape of starches measured by Scanning Electron Microscope showed polygonal and angular shaped granules with respective average granule diameter of 1.021 μm and 1.033 μm in C. album (LP) and C. album (LS). Furthermore, starch from both the varieties showed firmer gel texture with hardness values of 35.57 and 46.73 gs. The analyzed properties of two varieties of C. album show its applicability in various food stuffs where desired consistency and firmness are vital requirements. Overall, it is concluded, C. album starches could be a non-conventional viable source with ample intrinsic properties, encouraging its suitability in food and non-food applications.

Effect of hydrocolloids on microstructure, texture and quality characteristics of gluten-free pasta

Whole amaranth flour was used to prepare gluten free pasta with different hydrocolloids (guar gum, gum acacia and gum tragacanth) at different proportions (0.5 and 1.0%). Different flour blend formed from amaranth flour and hydrocolloids (guar gum, gum acacia and gum tragacanth) were tested for pasting profile. Amaranth flour blend with 1.0% guar gum showed maximum peak viscosity. Developed pasta samples were evaluated for colour analysis, cooking characteristics, texture profile analysis, morphological properties and sensory analysis which shows significant difference from semolina pasta (control). In gluten-free pasta, cooking loss ranged from 8.5 to 17.30%. Pasta with guar gum (1%) showed minimum cooking loss (8.5%). Our results showed that guar gum was best in terms of improving all aspects of gluten free pasta quality.

Stinging nettle (Urtica dioica L.): a reservoir of nutrition and bioactive components with great functional potential

In recent years a lot of the scientific interest has been concentrated on the identification of factors among low cost herbs that can be helpful in improving the health of humans. A shocking feature of herbal analysis has been that rarely any rare, exotic and exquisite plant has proved more fascinating. Typically some common, less familiar, and disdained weed have been discovered to possess undreamt of virtues. Urtica dioica is a weed and its seeds, leaves and even roots are used for medicinal purpose. It is a sensible reservoir of micronutrients and nutritional elements which leads us to focus our study on this herb. Despite of being wholesome, leaves are easily digested and high in minerals (especially iron), vitamin C and pro-vitamin A. U.dioica is used as both medicine and food in many countries particularly in Mediterranean region because of being widespread and having conjointly exceptional biological activities. This comprehensive review is an effort to summarise the recent data on nutrition, pharmacological and clinical effects of U. dioica keeping in view the increased demand by patients to use natural products with antioxidant activity, anti diabetic activity and having potential for treatment of inflammatory diseases. The review of nutritional properties is also an important aspect as every person needs general nutritional support in order to stay well or become optimally healthy. This review provides an overview of U. dioica in relation to antioxidant activity, anti diabetic activity, antimutagenic activity, antimicrobial activity, analgesic effect and treatment of inflammatory diseases that promotes its use.

Effect of pH and holding time on the characteristics of protein isolates from Chenopodium seeds and study of their amino acid profile and scoring

Alkali extraction and acid precipitation methods were adopted to isolate protein from quinoa and album seeds of variety Chenopodium. Different pH dispersions (3-11) of isolated proteins were prepared and effects of pH and holding time on protein characteristics were evaluated. The pH-10 of extraction medium was found suitable for protein extraction on the basis of yield, purity, solubility and colour having isoelectric pH of 4.5. Yield and purity of protein isolates (PI) of quinoa and album varied from 8.12 to 12.22%; 74.19 to 85.07% and 7.71 to 10.98%; 77.16 to 86.12%, respectively. Overall, pH and time had significant effect on functional properties of PI of both seeds. Quinoa PI had higher emulsifying activity, emulsion stability, water binding capacity and dispersibility, whereas, foaming capacity and stability were higher for album PI. Nutritional indices were 64.20 and 64.58 for quinoa and album PI, respectively, whereas, amino acid scoring (FAO, 2013) indicated, isoleucine, leucine and valine as the limiting amino acids.

Comparative study of raw and germinated Chenopodium ( Chenopodium album ) flour on the basis of thermal, rheological, minerals, fatty acid profile and phytocomponents

This study determined the effects of germination on the minerals, fatty acids, pasting, thermal, rheological and phytocomponents contents of Chenopodium album flour. The predominant fatty acids in raw flour were palmitic (0.83%), oleic (0.99%) and linoleic acids (1.96%), which increased significantly (p ≤ 0.05) with germination. Minerals (Na, Cu and Zn) and dietary fiber (soluble and insoluble) were increased with germination, while pasting and gelatinization properties were reduced significantly. Scanning electron micrographs showed destruction of the continuous composite structure of starch embedded in the dense protein matrix of flour following germination. Quantitative analysis of C. album flour by GC-MS revealed that germinated flour contained more phytocompounds than raw flour. This research suggests the potential of germination in enhanced product development and utilization of valuable bioactive compounds.

Molecular characteristics of oxidized and cross-linked lotus (Nelumbo nucifera) rhizome starch

ABSTRACT Lotus rhizome starch was isolated and subjected to chemical modification using different levels of oxidation, cross-linking, and dual modifications. Fourier transform infrared (FTIR) and X-ray diffraction analyses confirmed the successful modification of native starch. The carbonyl, carboxyl contents, and degree of cross-linking of modified starch were in the range of 0.03–0.07%, 0.07–0.15%, and 4.31–58.28%, respectively, for oxidized, cross-linked, and dual-modified starches. Amylose content varied from 13.57% to 20.60% for native and modified starches. Swelling power (SP) and solubility were temperature dependent and increased with increase in temperature. Oxidation and dual modification increased solubility, while cross-linking decreased solubility. Paste clarity, degree of crystallinity, and whiteness of starches increased significantly with increase in level of modifications. Peak, breakdown, and setback viscosities of the modified starches decreased with increase in modification. Phase transitions using DSC presented lower enthalpy values for modified starches. Gelatinization temperature increased due to modification whereas scanning electron micrographs revealed that modification altered the starch morphology.