SUSTAINABILITY OF THE PROBIOTIC LACTOBACILLUS CASEI IN FORTIFIED INDIAN MILK CAKES UNDER DIFFERENT PRESERVATION CONDITIONS-EFFECTS OF CO-IMMOBILIZATION OF L. CASEI AND COMMERCIAL PREBIOTIC INULIN (CHICORY BASED) AND MILLET INULIN

Abstract

Objective: The objective of the present article is to identify the most suitable Indian millet inulin for the growth of probiotic Lactobacillus casei and to evaluate the effects of the fortification vectors (probiotics and probiotic-prebiotic combination in immobilized conditions) and immobilization methods on the sustainability of L. casei in a fortified Indian sweet (milk cake) preserved under different conditions.Methods: Inulin was extracted from pearl, finger and great millets. The concentrations of L. casei, grown on three millet inulins, were compared in 24 h batch culture. The L. casei and probiotic-prebiotic combinations namely L. casei-commercial inulin and L. casei-pearl millet inulin were immobilized using entrapment, external and internal microencapsulation methods. The Indian milk cake samples were fortified with the immobilized probiotic cells, co-immobilized probiotic-prebiotic combinations. The fortified samples were preserved at different conditions (temperature: 4 °C and-20 °C; Time: 1-4 w). The sustainability of L. casei in the preserved samples was determined using spread plate method and the cell concentrations were compared among all fortified samples.Results: Pearl millet inulin is determined to be the most suitable millet inulin for the growth of L. casei. The synergistic combination of L. casei–pearl millet inulin, co-immobilized with internal gelation technique is the best fortification vector for the viability of L. casei in preserved food samples.Conclusion: The L. casei, co-immobilized with pearl millet inulin through internal gelation technique, can be utilized as an effective fortification vector for the sustainability of probiotic cells in preserved Indian milk cakes and similar food samples