Yogurt fortified with various protein hydrolysates: Texture and functional properties
Mahmoud Abdel-Hamid, Ahmed M. Hamed, Gavin Walker, Ehab Romeih
Abstract
This work evaluated the impact of incorporating 1% of commercial protein hydrolysates [rice protein hydrolysate (RPH), pea protein hydrolysate (PPH), and casein hydrolysate (CH)] on the functional, microstructure, and texture properties of set yogurt. Yogurt prepared with RPH exhibited the highest viability number of Streptococcus thermophilus. The addition of three hydrolysate types to yogurt revealed significant increases in the antioxidant and ACE-inhibitory activities, where the highest values were noted for the yogurt prepared with RPH. RPH exhibited no differences in texture properties (firmness, consistency, and cohesiveness) to control yogurt. These results were confirmed by scanning electron microscope examination. RPH and control yogurts showed compacted and dense structures accompanied by small pores, whereas CH and PPH yogurt structures were characterized by coarse networks with large voids. Furthermore, there was no significant impact of adding protein hydrolysates on the overall acceptability of yogurt as indicated by a sensory panel. • A functional yogurt was prepared with commercial protein hydrolysates (rice, pea, and casein). • The addition of protein hydrolysate improved the viability of yogurt culture. • Yogurt fortified with protein hydrolysate exhibited strong antioxidant and ACE-I activities. • Protein hydrolysate addition affected the texture and organoleptic properties of yogurt.