Product development based on kefir dehydrated by spray dryer

Abstract

Kefir is a probiotic food that has historical origin in the Caucasus Mountains. Its most common form of presentation is that of gelatinous grains, which when inoculated in milk produces an acidified fermented that is slightly carbonated, commonly called kefir or kefir milk. Kefir grains are composed of different strains of microorganisms that include yeasts, acid-lactic and acid-acetic bacteria that are attached to a polysaccharide matrix called Kefiran. Several benefits are attributed to Kefir, such as improved digestion and lactose tolerance, inhibition of growth of tumors and pathogenic microorganisms, regularization of intestinal transit, reduction of cholesterol, inhibition of angiotensin converting enzyme (ACE), and modulation of the immune system , including allergy and asthma relief. The production of kefir in Brazil is handmade, usually homemade and incompatible with the routine of the consumer of large cities. This project proposes the development of a dehydrated product that maintains the properties of kefir and that can be a practical and accessible option to the consumer, either as a supplement, or drink to be reconstituted for human or veterinary use. For this purpose, it is intended to use reconstituted whey powder in comparison to skimmed milk for the preparation of kefir and fermented must be dehydrated by spray-dryer. The proposed evaluation parameters for product development are the solids content in the reconstituted serum and the effect of microencapsulating agents. To evaluate the effect of solids content in both fermentation and drying, it is intended to test concentrations of 10 and 12% (w / w) whey and skimmed milk powder. After fermentation, the fermented serum will be dehydrated by spray-dryer with and without the addition of microencapsulating agents (pectin and gum arabic). Microencapsulating agents are expected to improve the survival of the microorganisms and the yield of the process. The products obtained will be evaluated for moisture, water activity and the survival of microorganisms. The conditions that generate products of better quality and good survival of microorganisms evaluated by physico-chemical, microbiological and metagenomic analyzes to identify microorganisms surviving the drying and storage conditions. It is expected that kefir fermented in whey and skim milk dehydrated with microencapsulants generate products of low cost of production and good survival that can be used as a practical option to the consumer who is interested in a live probiotic product with high diversity of microorganisms and which is rich in kefirane. There is currently no product in the Brazilian market based on dehydrated kefir that presents the characteristics of the product proposed here. "Kefir Real", a capsule supplement of vitamins and minerals containing lyophilized kefir in its composition marketed by a Brazilian company, does not claim viable microorganisms in its constitution. Other possible competitors are lyophilized products consisting of up to 4 strains of probiotic bacteria or yeast. This low microbiological diversity is an important limitation compared to kefir-based products. In addition, the lyophilization process is costly. For veterinary use, the companies Ouro Fino and Vetnil have several probiotic products also freeze-dried. Preliminary results already indicate the feasibility of this research in which it was possible to obtain lactic bacteria survival in the order of 9 log CFU / g after drying by spray dryer with fermentation in skimmed milk without addition of microencapsulants. It is expected that with the use of microencapsulants this survival will increase and the cost of the proposed product will be much smaller than the competition. (AU)