Study of the bacteria - encapsulating agent interaction in microencapsulation of probiotics

Abstract

An increasing number of microorganisms have been applied in the food industry, by incorporation in food products, in the development of probiotic ingredients and supplements, among others. This industrial use usually depends on preservation methods through dehydration, in order to ensure better metabolic activity. On the other hand, drying can cause loss of viability mainly due to cellular damage caused by this process. To avoid them, we can mention the use of microencapsulation, an important technique to improve bacterial stability during processing and application in food matrices. Thus, the objective of this thesis was to review the scientific literature on the microencapsulation of microorganisms, with a main focus on probiotics and the main encapsulating agents used by the lyophilization and spray dryer method. In this scenario, lactic acid bacteria stand out, which have been increasingly chosen in research and applications in food, especially in dairy products. Thus, in the first work, already published, a general review was carried out on microencapsulation of probiotic bacteria, focusing on spray drying and the main encapsulating agents cited in the literature for this encapsulation method. It was observed that in the literature the authors increasingly seek to optimize the production of dehydrated microbial cultures, which makes it necessary to know about the encapsulating materials and the main available and applicable methods. At the same time, they cite the need for more research, mainly to understand the protective effect, in order to guide the choice of conditions to be used in microencapsulation. Therefore, the second work brings a denser review of the literature, having as main focus the microencapsulation of lactic acid bacteria by lyophilization and spray dryer. In this article, the main hypotheses found in the literature about the negative effect of bacterial dehydration are discussed, as well as the protective action of carbohydrates, proteins and lipids used as encapsulating agents. To investigate the theories discussed, physicochemical analytical methods are suggested, in order to aid in the understanding of microencapsulation, together with microbiological methods already commonly used.Keywords: Microorganisms. Food. Viability. Drying. Spray dryer.