Relationship between protein characteristics and film‐forming properties of kidney bean, field pea and amaranth protein isolates

Abstract

Summary This study was undertaken to evaluate physicochemical (colour, protein content, ash content and zeta potential), structural (size exclusion chromatography and thermal properties) and film‐forming properties of kidney bean, field pea and amaranth protein isolates (KBPI, FPPI and AMPI, respectively). Protein content, ash content, zeta potential and denaturation temperature of the isolates ranged from 83.9 to 91.4%, 2.9 to 4.5%, −37.3 to −44.2 mV and 85.5 to 96.2 °C, respectively. Size exclusion chromatography revealed that globulins were prominent proteins in KBPI and FPPI, while AMPI contained both globulins and albumins as major fractions. FPPI showed the highest L* value (88.1), surface charge (zeta potential = –44.2 mV) and protein solubility (80.0–94.2%). Films were prepared from heated (90 °C for 20 min) and unheated protein dispersions of pH 7.0, 8.0 and 9.0 and evaluated for colour, opacity, tensile strength (TS), water‐solubilised matter (WSM) and water vapour permeability (WVP). FPPI films showed the most desirable properties in terms of the highest L* (87.5–90.5), TS (12.6–37.2 MPa) and the lowest opacity (7.1–8.4 A600/mm). FT‐IR spectroscopic analysis of the films revealed that alkaline pH and heat treatment unfolded protein molecules. Alkaline pH reduced opacity, while heat treatment improved TS and water resistance (decreased WSM and WVP) of protein films, which varied with the protein isolates.

Development of carboxymethyl xylan films with functional properties

“…The incorporation of the various components with CMX improved the mechanical properties of films as compared to the control. Similar results were reported by other authors (Shevkani and Singh 2015;Yu-Yue et al 2015;Jafarzadeh et al 2016) respectively with proteins, chitosan and semolina. The increase in mechanical properties can be explained by the formation of hydrogen bonds.…”

“…It should be noted that the addition of different materials to the control film reduces its yellowish. Polysaccharides-based films have higher transparency against protein-based films (Shevkani and Singh 2015). However it should be noted the lower thickness of the first films, presented in this work, which influences this property.…”

Bioactive constituents in pulses and their health benefits

“…Pulse proteins can be used in gluten-free products, including muffins and edible biodegradable films (Shevkani and Singh 2014;Shevkani and Singh 2015). Although historically the general health benefits of pulses have been associated with these macronutrients, yet nowadays there are sufficient evidences that suggest some non-nutritional compounds present in them also play a significant role in the maintenance of human health.…”

Effects of heat and pH treatments and in vitro digestion on the biological activity of protein hydrolysates of Amaranthus hypochondriacus L. grain

“…Considerable further research has been conducted by Shevkani and Singh (2015) and Shevkani et al (2014a, b) on several novel commodities derived from amaranth grain and their use in the design of N and FF. Chemical composition, physicochemical and techno-functional features of proteins, lipids and carbohydrates occurring in amaranth grain flour have been assessed.…”