Search Results (3)

Increasing the use of plant proteins in foods requires improving their physical and chemical properties, such as emulsification, gelation capacity, and thermal stability. These properties determine the acceptability and functionality of food products. Higher protein solubility significantly impacts these properties by affecting denaturation and the stability of emulsifiers or gels. Therefore, developing plant-based protein ingredients requires accurately and conveniently measuring their solubility. Colorimetric solubility methods overcome many issues of more robust combustion and titration methods, but complicated chemical mechanisms limit their applicability for certain proteins. This study aims to compare the effectiveness of four common colorimetric solubility measurement methods for pulse and non-pulse legume proteins and hydrolysates. Pea, chickpea, lentil, and soy protein isolates were made from defatted flour and their solubility at a range of pHs was measured using the Bradford, Lowry, bicinchoninic acid (BCA), and biuret methods. Solubility was also measured for chickpea and soy protein hydrolysates made using Alcalase and Flavourzyme. A comparison of the methods for solubility quantification revealed that the Bradford and Lowry methods most closely match the expected results for the unhydrolyzed protein, with the BCA and biuret methods underestimating solubility by 30%. The Lowry method was the preferred method for hydrolysate solubility measurement, with the Bradford method measuring 0% solubility at the isoelectric point due to an inability to interact with peptides that are soluble at this pH. This study identifies reliable methods for measuring plant protein solubility that establish uniform outcomes and enable a better comparison across studies, giving a consensus for key functional properties in food applications. Full article

Defatted chickpea flour (DCF), a rich source of protein and starch, is frequently utilized in the food industry. Two crucial methods of modifying food materials are high-pressure homogenization (HPH) and heat treatment (HT). This study investigates the effect of co-treatment (HPH-HT) on the particle size, rheological behavior, and thermal characteristics of DCF suspensions. The results indicate that both HPH and HT can result in a more uniform distribution of particle size in the suspensions. The effect of HPH on G′ was observed to be reductionary, whereas HT increased it. Nevertheless, the HPH-HT treatment further amplified G′ (notably in high-concentration DCF), which demonstrates that the solid properties of DCF are improved. The apparent viscosity of the suspensions increased with individual and combined treatments, with the HPH-HT treatment of DCF12% exhibiting the most significant increase (from 0.005 to 9.5 Pa·s). The rheological behavior of DCF8% with HPH-HT treatment was found to be comparable to that of DCF12% treated only with HT. In conclusion, HPH-HT treatment shows a synergistic impact of HPH and HT on the rheological properties of DCF suspensions, however, it has limited effect on the particle size distribution and freeze–thaw stability. Full article

Chickpeas are the third most abundant legume crop worldwide, having a high protein content (14.9–24.6%) with interesting technological properties, thus representing a sustainable alternative to animal proteins. In this study, the surface and structural properties of total (TE) and sequential (ALB, GLO, and GLU) protein fractions isolated from defatted chickpea flour were evaluated and compared with an animal protein, ovalbumin (OVO). Differences in their physicochemical properties were evidenced when comparing TE with ALB, GLO, and GLU fractions. In addition, using a simple and low-cost extraction method it was obtained a high protein yield (82 ± 4%) with a significant content of essential and hydrophobic amino acids. Chickpea proteins presented improved interfacial and surface behavior compared to OVO, where GLO showed the most significant effects, correlated with its secondary structure and associated with its flexibility and higher surface hydrophobicity. Therefore, chickpea proteins have improved surface properties compared to OVO, evidencing their potential use as foam and/or emulsion stabilizers in food formulations for the replacement of animal proteins. Full article