Storage stability of soy protein isolate powders containing soluble protein aggregates formed at varying pH

Abstract

Soy protein is widely used in food formulations, nutraceutical products, and beverages as an inexpensive functional and health-promoting ingredient (Wang, Liu, Ma, & Zhao, 2019). However, the protein solubility of soy protein often decreases during storage (Martins & Netto, 2006; Pinto, Lajolo, & Genovese, 2005). For example, soy protein isolate (SPI) solubility decreases by about 63% after 1-year storage at 42°C (Pinto et al., 2005). This insolubility of soy protein seriously affects its commercial applications because solubility plays an important role in the gelling and emulsifying properties of this functional ingredient (Hua, Cui, Wang, Mine, & Poysa, 2005). Therefore, to meet the high demand of soy protein for food, nutraceutical, and beverage applications, several studies have been conducted to investigate the factors that might impact the structural and functional properties and the mechanism involving in storage instability of soy protein in the solid state. The relative humidity (RH) and temperature are two main environmental conditions that affect the storage stability of soy protein. High RH and high temperature have been found to accelerate

Changes in partial properties of glycosylated egg white powder during storage

“…With the degree of glycosylation increasing, the protein thermal stability decreased, and the protein conformation partially expanded. 5,52,53 Some researchers suggested that the decrease of 4H d was related to protein aggregation, 55 which was consistent with the previous solubility studies in this study. The decrease in 4H d of 1:2-1.5 was the most significant, as was the decrease in solubility.…”

Robust Piezoelectric Biomolecular Membranes from Eggshell Protein for Wearable Sensors

“…As displayed in Figure S13, the SEP/PEO films start being damaged at the corners from the first second of the complete immersion in different types of water and dissolve relatively slowly in acidic solutions at 10 s. This is probably because the pH of acidic solution is close to the isoelectric point of the protein, resulting in stronger interaction between proteins, which reduces the dissolution of the protein. 61 The degradation process of the three films completes in about 30 s. Also, the electrodes show no significant degradation after 72 h, which demonstrates their potential in supporting and protecting the films. The results indicate that the as-prepared nanofiber has good biodegradability, which reduces the burden of environmental pollution caused by electronic products to a certain extent.…”

“…Finally, the film completely degrades within 30 s. Besides, we have tested the degradation of SEP/PEO films in different types of water (NaCl solution, NaOH solution, and acetic acid solution). As displayed in Figure S13, the SEP/PEO films start being damaged at the corners from the first second of the complete immersion in different types of water and dissolve relatively slowly in acidic solutions at 10 s. This is probably because the pH of acidic solution is close to the isoelectric point of the protein, resulting in stronger interaction between proteins, which reduces the dissolution of the protein . The degradation process of the three films completes in about 30 s. Also, the electrodes show no significant degradation after 72 h, which demonstrates their potential in supporting and protecting the films.…”

A Review of Bioactive Compound Effects from Primary Legume Protein Sources in Human and Animal Health

“…The denaturation temperature of glycinin is higher (75.7 • C) compared to β-conglycinin (60.5 • C) at a 1% weight concentration. Conversely, β-conglycinin exhibits slower rates of aggregation and densification [105]. Thermal aggregation kinetics reveal that β-conglycinin has a slower rate of aggregation and densification, with monomers still observed at 100 • C, which eventually form soluble aggregates of limited size.…”

“…Thermal aggregation kinetics reveal that β-conglycinin has a slower rate of aggregation and densification, with monomers still observed at 100 • C, which eventually form soluble aggregates of limited size. In contrast, the densification and nucleation processes of glycinin are quicker, resulting in insoluble aggregates with densified cores [105]. Thus, glycinin contributes to gel hardness, while β-conglycinin contributes to gel elasticity.…”