Development and characterization of biodegradable films from whey protein concentrate, psyllium husk and oxidized, crosslinked, dual-modified lotus rhizome starch composite.

BACKGROUND: The combined effect of variously chemically modified lotus rhizome starch, whey protein concentrate, psyllium husk and glycerol was evaluated on developed biodegradable films. RESULTS: Dual-modified lotus rhizome starch composite films presented minimum solubility and water vapor permeability and maximum tensile strength among native and modified starch composite films. Elongation at break of dual-modified starch composite films (FLCOS1 , FLCOS2 ) was found to be a maximum, whereas a decrease was observed for FLCOS3 . Oxidized lotus rhizome starch composite films were the most transparent among native and modified starch composite films, whereas crosslinked lotus rhizome starch composite films were the least transparent. Scanning electron microscopy indicated a homogeneous compact surface of oxidized starch composite films, whereas troughs were observed in crosslinked and dual-modified starch composite films. Using whey protein concentrate, psyllium husk and glycerol without any phase separation, smoother films and with compact microstructures were produced. Fourier transform infrared analysis revealed additional peaks for modified starch films, confirming greater interaction among starch and film-forming components, whereas amorphous structure was indicated from X-ray diffraction results of modified starch composite films. CONCLUSIONS: Owing to various properties of modified starches, these films find application in edible contact packages and can better be used for products where higher structural integrity and lower water vapor transmission are needed. © 2019 Society of Chemical Industry.

Physicochemical, pasting, rheological, thermal and morphological properties of horse chestnut starch.

Indian Horse chestnuts contain high content of starch which can be explored to be used in various applications in food industry as encapsulating agent, stabilizer, binder, thickener, gelling agents and many more. Horse chest nut is locally available and can be a boon for food industry if the inherent properties are explored. Hence, horse chest nut starch can be a better option for the replacement of conventional starches to meet the industrial demand of starch. Physicochemical, pasting, rheological, thermal and morphological properties of starch isolated from Indian Horse chestnut (HCN) were determined. Amylose content was found to be 26.10 %. Peak viscosity obtained from RVA profile was 4110 cP. Hardness, cohesiveness, adhesiveness and gumminess were determined by Texture Profile Analyser. Particle size analysis showed a typical Uni modal size distribution profile with particle distribution ranging from 7.52 to 27.44 µm. The shape of starch granules varied from round, irregular, oval, and elliptical with smooth surface. X- ray diffraction revealed that HCN starch showed a typical C-type pattern with characteristic peaks at 5.7, 15.0, 17.3 and 22.3°. The transition temperatures (To, Tp, and Tc) and enthalpy of gelatinization (ΔH) values were 53.35, 58.81, 63.57 °C and 8.76 J/g, respectively. The rheological properties were determined in terms of variation of storage modulus (G (/)), loss modulus (G (//)) and loss factor (tan δ) at different temperatures. Peak G (/), peak G (//) and peak tan δ values were observed as 10,400 Pa, 1,710 Pa, and 0.164, respectively.

Exploring the potential of browntop millet (Urochloa ramosa) starch: Physicochemical, morphological, thermal and rheological properties across four cultivars.

This comprehensive research explores the starch isolated from four browntop millet cultivars to determine physicochemical, thermal, morphological, powder flow, pasting, and rheological properties. Significant variations (p ≤ 0.05) were observed among the cultivars. Aerated bulk density (ABD) and Tapped bulk density (TBD) values ranged from 0.476 g/mL (BTM4) to 0.591 g/mL (BTM1), and 0.591 g/mL (BTM1) to 0.476 g/mL (BTM4). Amylose content varied from 22.55% (BTM4) to 25.86% (BTM3), influencing gelling strength and film-forming properties. Water absorption capacity ranged from 1.78 g/g to 1.92 g/g, while oil absorption capacity varied from 2.20 g/g to 2.47 g/g. DSC analysis showed gelatinization temperatures (Tp, and Tc) ranging from 85.44-91.61 °C, and 147.08-154.21 °C, respectively. X-ray diffraction (XRD) patterns revealed A-type crystalline patterns, with relative crystallinity ranging from 22.66% (BTM3) to 27.81% (BTM2). Pasting properties exhibited variations among cultivars, with peak viscosity ranging from 2480 c P to 3119 cP, and pasting temperature from 77.50 °C to 82.35 °C. Rheological analysis indicated shear-thinning behavior. The findings offer insights into the diverse properties of browntop millet starch, contributing to its potential applications in various industries and potentially guiding future studies on browntop millet starch modifications and novel utilization.

Retention of bioactive compounds during extrusion processing and storage.

Retention of bioactive compounds (beta-glucans, lignans and gamma oryzanol) was analyzed after extrusion and during storage period of three months under four relative humidities using saturated salt solutions such as potassium carbonate (43.26%), magnesium nitrate (52.60%), potassium chloride (84.36%) and potassium nitrate (93.58%). The control sample comprising a corn and rice flour blend (50 g each) was substituted with beta-glucans at 3 g/100 g and 6 g/100 g, flaxseed lignans at 6.67 g/kg and 11.67 g/kg and gamma oryzanol at 1.5 g/100 g and 3.0 g/100 g at low and high levels, respectively. After extrusion, beta-glucan was retained up to 82.67 and 90.83%, lignans were retained at 86.31 and 66.66% whereas retention of gamma oryzanol was 71.33 and 51.67% at low and high level of substitution, respectively. Retention of bioactive compounds was the lowest along with a decrease in L* and b* values and an increase in a* value was observed under higher relative humidity (84.36% and 93.58%) storage conditions.

Combined effect of pH treatment and the extraction pH on the physicochemical, functional and rheological characteristics of amaranth (Amaranthus hypochondriacus) seed protein isolates.

Results for the effect of extraction pH and pH treatment on the functional, physicochemical, rheological and thermal characteristics of amaranth protein isolates (APIs) are reported in this study. Four amaranth protein isolates (P1, P2, P3 and P4) were prepared by varying the extraction pH (9-11). These four protein isolate samples were further treated at pH values from 3 to 9. The total protein content and purity of protein isolates were found to be higher for P1 than P2, P3 and P4 samples. The particle size of P1 was significantly (p ≤ 0.05) higher (299.68 µm) than other samples. Solubility, emulsifying capacity and stability, foaming properties, water and oil binding capacities were higher for the P1 sample treated at pH 9. Gelation characteristics like storage modulus (G') and loss modulus (G") were higher for P1 samples. APIs obtained at extraction pH 9 (P1) also exhibited better thermal properties in comparison with other three samples.

Influence of alkali treatment on physicochemical, pasting, morphological and structural properties of mango kernel starches derived from Indian cultivars.

Present investigation was aimed to characterize the influence of alkali treatment on physicochemical, pasting, morphological and structural properties of mango kernel starches from three cultivars viz. Safeda, Chausa, Dussheri when treated with 0.1, 0.25 and 0.5% NaOH for 0, 5 and 10 days at 25 °C. Alkali treated starches have shown significant reduction (p < 0.05) in water binding capacity and amylose content whereas significant increase was observed in solubility and swelling power when compared with their native counterparts. Pasting properties of modified starches have shown significant changes from their respective native ones with highest reduction observed in Dussheri. Morphology was slightly affected by alkali treatment reflected as dents and grooves on the surface of starch granules. X-ray diffraction patterns were typically A-type, similar to native starches with decrease in crystallinities. IR spectra remained unaffected even after prolonged treatment. Thus, the time duration and concentration of alkali had played critical role in changing the physicochemical, pasting and morphological properties of mango kernel starches that could be potentially utilized for application in innovative products to enhance their textural and sensory attributes.

Structural modification of quinoa seed protein isolates (QPIs) by variable time sonification for improving its physicochemical and functional characteristics.

High intensity ultrasound treatment (HIUS) by probe method is a novel technique to impart desirable physical, structural and functional characteristics to the native proteins structures. In this concern, effect of HIUS treatment at variable intervals from 5 to 35 min on quinoa seed protein isolates (QPIs) characteristics was analyzed. A typical dynamic rheological characteristic curve of QPIs had been obtained as a result of HIUS treatments at variable time intervals. Higher sonication resulted in the formation of large protein aggregates with higher particle size which increased QPIs turbidity. Temperature and frequency sweep tests had shown dominance of storage modulus over loss modulus, thus described strong gelling behavior of treated QPIs. HIUS treatment reduced particle size of QPIs with improved its flow properties. No splitting of bands had occurred due to sonication, whereas, more intensity of bands of treated QPIs depicted its greater water solubility. HIUS treatment decreased fluorescence intensity of QPIs whereas, no significant changes in Amide-II & III regions of QPIs occurred except decrease in wave number. The effects of HIUS on QIPs isolates had shown completely different response than those of results of quinoa protein extracts. Moreover, the studies conducted on quinoa protein extracts provided detailed information about the effect of HIUS on structural changes and its impact on physicochemical, functional and rheological characteristics.

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.

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.