Improved viability of probiotics by encapsulation in chickpea protein matrix during simulated gastrointestinal digestion by succinylated modification

The potential application of succinylated chickpea protein (SCP) as a wall material for spray-dried microencapsulated probiotics was investigated. The results showed that succinylation increased the surface charge of chickpea proteins (CP) and reduced the particle size of the proteins. Meanwhile, succinylated modification decreased the solubility of protein under acidic conditions and increased the solubility in alkaline conditions. The effects of spray drying and in vitro gastrointestinal digestion on probiotics were investigated by microencapsulating chickpea protein with different degrees of N-succinylation. The results showed that all microcapsules had similar morphology, particle size and low water content. The microcapsules prepared by succinylated chickpea protein showed better stability and viability during spray drying and gastrointestinal digestion. The protective effect of probiotics was better as the degree of N-succinylation increased. In particular, the SCP-3-P sample (10 % succinic anhydride modified CP and maltodextrin) lost only 0.29 Log CFU/g throughout gastrointestinal digestion. The superior protective effect provided by succinylated CP in simulated gastric fluid (SGF) was mainly attributed to the reaction of succinic anhydride with protein to cause protein aggregation under gastric acidic conditions, reducing the infiltration of gastric acid and pepsin and maintaining the structural integrity of the microcapsules. Therefore, these findings provide a new strategy for probiotic intestinal delivery and application of chickpea protein.