this search, yogurt was fermented using the goat milk treated with different
concentrations of transglutaminase (TG; 1,2,3 u/g protein)at 40℃ for 2h to investigate the effects of TG concentration on yogurt
coagulation time, and the acidity, water holding capacity, texture
characteristics and microstructure at the end of fermentation and 24 hours’
post-fermentation.The results showed that the coagulation time of the goat milk
treated by TG gradually decreased with the increase of TG concentration, but
the acidity in curd and fermentation of 24 h had no significant change (p> 0.05) when added different
concentrations of TG. The water holding capacity of goat yogurt could be
with TG treatment, especially when the concentrationof TG was 2 to 3 u/g
protein.The texture analysis showed that hardness and viscosity at the end of
fermentation and post-fermentation of 24h ofgoat yogurtincreased significantly
with the increase of TG concentration(p>0.05).
TG processing had no significant effect on cohesiveness of goat milk at the end
of fermentation (p>0.05), while it
had significant influence on cohesiveness after fermentation of 24 h (p<0.05). However, TG treatment had
little effect on goat yogurt elasticity (p>0.05).
By observing the microstructure of acid goat milk, it was found that the
protein in goat's milk treated with TG concentration of 2 ~ 3 u/g protein
easier to form denser network structure, which facilitated the formation of
goat yogurtgels. Overall , the gel properties of goat milk could be improved
with the TG treatment in concentration of 2 ~ 3u/g protein.