Viability of microencapsulated probiotic lactobacilli during storage at different temperatures

The aim of this study was to develop technological and microbiological basics for the use of microencapsulated probiotics in meat products. Probiotic Lactobacillus (L.) reuteri, L. rhamnosus, L. paracasei and L. gasseri strains were chosen for potential use in meat products. The effects of spices and NaCl on the microbiological stability were investigated in pilot studies. Lyophilised samples were stored for 6 months withoud additives. Microencapsulation was done with water-soluble and water-insoluble coatings. Samples were stored at 2 degrees C and 20 degrees C for six months in gelatine solutions: without additives, with 5% NaCl, with 10% cloves and with 10% black pepper. Spices and salt exhibited a strong inhibitive effect on the bacterial counts of the tested strains. During storage the lyophilised probiotic strains were stable at 2 degrees C and at 20 degrees C. Protective effects of the microencapsulation however were heterogenous. Although at the beginning protective effects against the antimicrobial activity of cloves were shown for L. rhamnosus, none of the tested coatings were able to protect durably. L. paracasei proved to be very stable in general. The use of probiotic lactobacilli strains in meat products seems possible as protective effects of the microencapsulation were recognised. However, these effects must be tested for each specific application, e.g. strain/additive combination, due to individual strain differences.