The limited solubility and stability of pea proteins hinder their utilization in liquid formulations. In this study, protein glutaminase (PG) was employed to modify pea protein isolates (PPIs) and obtain deamidated PPI with varying degrees of deamidation (DD, 10–25%). The solubility and thermal stability of these deamidated PPI samples were assessed, and a comprehensive analysis, including SDS-PAGE, zeta potential, FTIR, surface hydrophobicity, and intrinsic fluorescence, was conducted to elucidate the mechanism behind the improvement in their functional properties. The results reveal that PG modification greatly enhances the solubility and heat stability of PPI, with the most notable improvements observed at higher DD (>20%). PG modification increases the net charge of PPI, leading to the unfolding and extension of the protein structures, thus exposing more hydrophobic groups. These structural changes are particularly pronounced when DD exceeds 20%. This increased electrostatic repulsion between carboxyl groups would promote protein unfolding, enhancing interactions with water and hindering the aggregation of unfolded protein in the presence of salts at elevated temperatures (supported by high-performance size exclusion chromatography and transmission electron microscopy). Accordingly, PG-mediated deamidation shows promise in enhancing the functional properties of PPI.

Oil bodies (OBs) are naturally occurring pre-emulsified oil droplets that have broad application prospects in emulsions and gels. The main purpose of this research was to examine the impact of the OB content on the structure and functional aspects of acid-mediated soy protein isolate (SPI) gel filled with OBs. The results indicated that the peanut oil body (POBs) content significantly affected the water holding capacity of the gel. The rheological and textural analyses showed that POBs reduced the gel strength and hardness. The scanning electron and confocal laser scanning microscopy analyses revealed that POBs aggregated during gel formation and reduced the gel network density. The Fourier transform infrared spectrum (FTIR) analysis demonstrated that POBs participated in protein gels through hydrogen bonds, steric hindrance and hydrophobic interactions. Therefore, OBs served as inactive filler in the acid-mediated protein gel, replaced traditional oils and provided alternative ingredients for the development of new emulsion-filled gels.

Background/Objectives: An inappropriate intake of dietary fats can disrupt the homeostasis of intestinal microbiota, affect the host’s metabolic status, and increase the risk of chronic diseases. The impact of dietary fat types on the composition and metabolic functionality of the intestinal microbiota has become a research focus over recent years. The objective of this study was to explore the effects of regular peanut oil (PO) and high-oleic-acid peanut oil (HOPO) on the composition and metabolic function of the intestinal microbiota. Methods: A dietary intervention test was conducted on SD rats fed a high-fat/high-fructose (HFF) diet. The composition and metabolic functionality of the intestinal microbiota of the experimental rats were investigated by 16S rRNA gene sequencing and fecal metabolomics. Results: Compared with saturated fat, PO and HOPO enhanced the diversity of intestinal microbiota in HFF diet-fed rats. Compared with PO, HOPO significantly increased the relative abundance of Lachnospiraceae_NK4A136_group and Harryflintia (p < 0.05), which are able to generate butyrate and acetate. Compared with saturated fat, 318 and 271 fecal biomarkers were identified in PO and HOPO groups, respectively. In contrast, 68 fecal biomarkers were identified between the PO and HOPO groups. The inhibition of harmful proteolytic fermentation in the colon may represent the main regulatory mechanism. With regard to metabolic status, HOPO provided better control of body weight and insulin sensitivity than PO. Conclusions: Compared with saturated fat, peanut oils better regulated the composition and metabolic function of the intestinal microbiota. In addition, HOPO exhibited better regulatory effects than PO.