Effect of Transglutaminase Pre-Crosslinking Treatment Incorporated with Glucono-δ-lactone on the Physicochemical and Digestive Properties of Tofu

Synergistic effects of microbial transglutaminase and apple pectin on the gelation properties of pea protein isolate and its application to probiotic encapsulation

The low gelation capacity of pea protein isolate (PPI) limits their use in food industry. Therefore, microbial transglutaminase (MTG) and apple pectin (AP) were combined to modify PPI to enhance its gelling characteristics, and the mechanism of MTG-induced PPI-AP composite gel generation was investigated. PPI (10 wt%) could not form a gel at 40 °C, while MTG-treated PPI (10 wt%) formed a self-supporting gel at 40 °C. Subsequently, the addition of AP further promoted the crosslinking of PPI and significantly improved the water holding capacity, rheology, and strength of PPI gels, which was attributed to both hydrogen and isopeptide bonds in the composite gel. Additionally, the PPI-AP composite gel showed excellent protection ability, and the survival rate of probiotics could reach over 90%, which could be used as an effective delivery system. This study verified that MTG and AP were efficient in enhancing the functional quality of PPI gels.

Effects of Glucono-δ-Lactone and Transglutaminase on the Physicochemical and Textural Properties of Plant-Based Meat Patty

Due to growing interest in health and sustainability, the demand for replacing animal-based ingredients with more sustainable alternatives has increased. Many studies have been conducted on plant-based meat, but only a few have investigated the effect of adding a suitable binder to plant-based meat to enhance meat texture. Thus, this study investigated the effects of the addition of transglutaminase (TG) and glucono-δ-lactone (GdL) on the physicochemical, textural, and sensory characteristics of plant-based ground meat products. The addition of a high quantity of GdL(G10T0) had an effect on the decrease in lightness (L* 58.98) and the increase in redness (a* 3.62). TG and GdL also decreased in terms of cooking loss (CL) and water holding capacity (WHC) of PBMPs. G5T5 showed the lowest CL (3.8%), while G3T7 showed the lowest WHC (86.02%). The mechanical properties also confirmed that G3T7-added patties have significantly high hardness (25.49 N), springiness (3.7 mm), gumminess (15.99 N), and chewiness (57.76 mJ). The improved textural properties can compensate for the chewability of PBMPs. Although the overall preference for improved hardness was not high compared to the control in the sensory test, these results provide a new direction for improving the textural properties of plant-based meat by using binders and forming fibrous structures.

Comparison on Protein Bioaccessibility of Soymilk Gels Induced by Glucono-δ-Lactone and Lactic Acid Bacteria

In this study, the protein bioaccessibility of soymilk gels produced by the addition of glu-cono-δ-lactone (GDL) and fermentation with lactic acid bacteria (LAB) was examined using an in vitro gastrointestinal simulated digestion model. The in vitro protein digestibility, soluble protein content, free amino acids contents, degree of hydrolysis, electrophoretic patterns, and peptide content were measured. The results suggested that acid-induced soymilk gel generated by GDL (SG) showed considerably reduced in vitro protein digestibility of 75.33 ± 1.00% compared to the soymilk gel induced by LAB (SL) of 80.57 ± 1.53% (p < 0.05). During the gastric digestion stage, dramatically higher (p < 0.05) soluble protein contents were observed in the SG (4.79−5.05 mg/mL) than that of SL (4.31−4.35 mg/mL). However, during the later intestinal digestion phase, the results were the opposite. At the end of the gastrointestinal digestion phase, the content of small peptides was not significantly different (p > 0.05) between the SL (2.15 ± 0.03 mg/mL) and SG (2.17 ± 0.01 mg/mL), but SL showed higher content of free amino acids (20.637 g/L) than that of SG (19.851 g/L). In general, soymilk gel induced by LAB had a higher protein bioaccessibility than the soymilk gel coagulated by GDL.