The viability of probiotic Lactobacillus paracasei IMPC2.1 coating on apple slices during dehydration and simulated gastro-intestinal digestion

A pectin coated dehydrated apple snack containing >=9 log colony forming unit/20 g portion of the probiotic Lactobacillus paracasei IMPC2.1, was developed. The strain was incorporated into the apple slices using vacuum impregnation (IP1) or soaking/stirring (IP2); apple slices where then coated with citrus pectin and dehydrated at 4oC for 14 days. Microbial application led to colonization of the apple surface, as seen by scanning electron microscope images, and all probiotic products showed comparable radical scavenging activity and total phenol content. IP2 led to better bacterial survival during 30 days storage at 4oC and color parameters comparable to the fresh apple. The simulated gastro-intestinal (GI) digestion confirmed the ability of the strain to survive the digestive process. This inclusion/coating/dehydration process led to a probiotic snack, which could successfully deliver bacterial cells in viable form to the GI tract.