Production of the functional milk chocolate with probiotic bacteria in a ball mill

Abstract

Increasing interest in “health” foods in recent years has stimulated innovation and new product development in the food industry around the world. Modern consumers expect their food to be healthy and to prevent illness as they are increasingly interested in their personal health. This explains the reason for a rising interest in probiotic health-based products. Probiotic milk chocolate is a novel approach in the area of successful applications of lactic acid bacteria, including their probiotic strains, for manufacturing other products and not just dairy products. Chocolate is a very popular food due to its unique organoleptic properties such as sweet taste and pleasant characteristic aroma. Chocolate as a complex emulsion is a luxury food that during consumption evokes a range of stimuli that activate pleasure centers of the human brain. Enrichment of chocolate with viable cells of lactic acid bacteria and development of modified technology of chocolate manufacturing to provide survival of these bacteria would contribute to enhanced beneficial impact of this product on human health. The requirement for the probiotic chocolate to be accepted by consumers is that the taste of chocolate remains unchanged, as well as its solubility, and that the bacteria survive during the entire period of use. The aim of this paper is to examine the sustainability of three strains of probiotics: Lactobacillus acidophilus NCFM, Lactobacillus rhamnosus HN001 and Bifidobacterium lactis HN019 in milk chocolate (produced in ball mill) after 6 months of storage at 20°C. Furthermore, to determine the best time for incorporating probiotic cultures into the chocolate in order not to disturb the chocolate production process. The impact of probiotics on antioxidative capacity of chocolate, particle size distribution, rheological and sensory properties of milk chocolate will be examined through a comparative review of milk chocolate with and without probiotics. Results show that strains of L. acidophilus and L. rhamnosus successfully survive in milk chocolate during 6 months of storage at room temperature. The survival of these cultures was above 90%. However, B. bifidum did not display satisfactory viability during storage. The total phenols content and antioxidant activity by DPPH assay in probiotic chocolate were higher in comparison with the chocolate without probiotics. Inoculation temperature of 40°C has significantly influenced the number of viable cells of L. acidophilus NCFM and L. rhamnosus HN001, as well as hardness, rheological and sensory properties of probiotic chocolate. Higher quality parameters were achieved in all chocolate masses where the inoculation was performed at 40°C.