Effect of α-lactalbumin hydrolysate-calcium complexes on the fermentation process and storage properties of yogurt

•α-lactalbumin hydrolysate-calcium (α-LAH-Ca) complexes promote S. thermophilus growth.•Its addition produced similar rheological properties and viscosity, less whey separation compared to control.•It accelerates fermentation, attenuates postacidification, and stabilizes storage properties of yogurt.

The effect of α-lactalbumin hydrolysate-calcium (α-LAH-Ca) complexes on the growth of lactic acid bacteria, fermentation kinetics, rheological and storage properties of yogurt was investigated. The α-LAH-Ca complexes exhibited growth-promoting activity on Streptococcus thermophilus (S. thermophilus), while a negative growth effect of Lactobacillus bulgaricus (L. bulgaricus) was observed. The complexes increased the maximum acidification rate (Vm), average acidification rate (0T/h), and titration acidity (TA) significantly, but they shortened the fermentation period, time to pH 4.6 (TpH4.6), and time to Vm (Tvm) (P < 0.05). Compared with the control without complexes supplement, yogurt with an addition of 20 mg/100 mL complexes exhibited no significant difference in storage modulus (G′) and yield stress (P > 0.05). In addition, the addition of complexes at 10 mg/100 mL and 20 mg/100 mL decreased whey separation (P < 0.05) and obtained a similar viscosity to the control during the later period of storage. Reduction of post-acidification and L. bulgaricus viable counts in yogurt with added α-LAH-Ca complexes was also observed during the storage period (P < 0.05). The addition of an appropriate amount of α-LAH-Ca complexes accelerated the fermentation process, attenuated post-acidification, and stabilized the storage properties of yogurt. Therefore, α-LAH-Ca complexes may possess good potential as a calcium-enriched vehicle in yogurt production.