Co-encapsulation of Lactobacillus plantarum and EGCG: A promising strategy to increase the stability and lipid-lowering activity

Probiotics and epigallocatechin gallate (EGCG) are sensitive to external conditions. In order to improve the survival rate of Lactobacillus plantarum (LP) and the activity of EGCG during storage, freeze-drying and gastrointestinal digestion, the LP and EGCG are co-encapsulated for the first time by extrusion using alginate-whey protein isolate (ALG-WPI) and alginate-pectin-whey protein isolate (ALG-PEC-WPI) biocomposites as wall materials, which can protect the encapsulated LP and EGCG during the simulated gastric digestion and co-release LP and EGCG in the intestine. Compared with ALG-PEC-WPI-LP beads, the release rate of LP in ALG-PEC-WPI-LP-EGCG beads is significantly increased to 92.8%. Both co-encapsulated beads are formed through hydrogen bonding interaction, and EGCG exists in amorphous form. Two co-encapsulated beads ALG-WPI-LP-EGCG and ALG-PEC-WPI-LP-EGCG exhibit better survival rate for LP during freeze-drying and in vitro digestion. Experiments conducted in high-fat diet-fed rats indicate that serum total cholesterols and low-density lipoprotein cholesterols in co-encapsulated group are significantly lower than those of un-encapsulated group. The co-encapsulated LP and EGCG alleviate the gut dysbiosis and decrease the hepatic steatosis in high-fat diet-fed rats. Thus the ALG-PEC-WPI composite is a good carrier for protection and delivery of LP and EGCG.