Protein glutaminase (PG) significantly enhances the textural properties of yogurt;however, research on its influence on yogurt fermentation characteristics and post-acidification during storage is limited.This study aimed to investigate the effects of varying concentrations of PG (0.03, 0.06, 0.09, and 0.12 U/mL) on yogurt fermentation characteristics, changes in acidity during storage, and textural attributes.The study suggested that treatment with 0.03 U/mL PG did not substantially increase acidity;however, higher PG concentrations led to enhanced post-acidification.Furthermore, as PG concentration increased, the yogurt demonstrated improved water-holding capacity, apparent viscosity, hardness, and adhesion, enhancing textural properties and stability.The results indicated that the protein hydrolysis capacity increased by 0.32 mEq NH3/L following treatment of the milk matrix with 0.03 U/mL of PG.Additionally, the acidity of yogurt treated with 0.03 U/mL PG reached 70 °T after 7 hours.At 21 days of storage, the lactic acid content of yogurt treated with 0.03 U/mL PG was measured at 8.566 mg/g, resulting in only a 6.24 °T increase in acidity.Compared with the control group, yogurt treated with 0.03 U/mL PG led to a notable enhancement in the yogurt’s water-holding capacity, increasing it by 5.3%.Additionally, there was a substantial augmentation in the yogurt’s hardness, which rose by 10.9 g, along with a significant boost in adhesiveness, cohesiveness, and chewiness, amounting to 4.8 g, 6.4 g, and 0.05 mJ, respectively.In summary, yogurt treated with 0.03 U/mL PG exhibited minimal post-acidification while maintaining significantly higher viable bacterial counts, alongside enhanced rheological and textural properties.This study provides a theoretical foundation for utilizing PG to mitigate the post-acidification phenomenon in yogurt.
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