Delivery of probiotic bacteria in long life ambient stable foods using a powdered food ingredient

摘要

Purpose - The authors aim to report a novel encapsulation technology for probiotic bacteria, through which L. casei CRL431 cells have been successfully delivered in shelf stable dry and intermediate moisture foods. Design/methodology/approach - Manufacturing of the probiotic ingredient involved a proprietary technique using combination of controlled fermentation of the L casei CRL431 cells, encapsulation in a food grade matrix and drying under controlled parameters. Findings - The developed ingredient was stored at 25℃ for a period of 12 months. The loss in cell viability was 1.9 log cfu g-1 after 12 months and maintained at 8.3 log cfu g-1. In vitro gastric juice and bile salts incubation revealed that the probiotic cells were better protected within the encapsulated than in the free form. The survival of the encapsulated cells was 5.0 and 2.1 log cycles higher than free cells in gastric juice and bile salt solution respectively. Fortification of probiotic bacteria did not have any negative impact on the sensory qualities of the foods mentioned above. Research limitations/implications - The developed technology is only applicable for fortifying dried or intermediate moisture foods with beneficial probiotic bacteria. The water activity of the products needs to be ranged from 0.2 to 0.5. A higher moisture contained food will lead to bacterial proliferations, product spoilage and loss in storage viability of the fortified probiotic cells. Practical implications - A general guideline issued by FAO/WHO states that any good effect of probiotic bacteria on human health can be obtained only if consumed at a level of 10^7 to 10^8 viable cells per day. Delivery of such a concentration of live probiotic cells is particularly challenging in the case of long shelf life foods. As shown in the results, the authors' probiotic powder is able to deliver over 100 million live cells per gram after 12 months of ambient storage. Even the foods fortified with this powder are able to deliver over 1 million cells per gram after six months of ambient storage. Social implications - The developed technology rightly identified the gap for fortifying probiotic bacteria into foods stored under ambient conditions which is a real hindrance to reach out to consumers particularly in the developing countries where refrigerated supply chain and storage are not yet established in an efficient way. It is believed that millions of people in developing countries with a tropical climate would be benefited with the goodness of probiotic bacteria using the help of this technology. Originality/value - The research work presented here is completely original and in-house research output of the Riddet Institute, Massey University, New Zealand. A successful commercialization of this new novel technology is deemed to be of very high value to any institution.