Estudo cinético da fermentação de kefir e kombucha em extrato hidrossolúvel de amêndoa de castanha de caju (Anacardium Occidentale L.)

Abstract

Around the world, there is an increasing number of adepts for diets with fewer animal products, justified in the search for a healthier life and to contribute to the preservation of the environment. Thus, plant-based diets are a global trend that revolves around vegetable foods, with fewer food additives, with products known to the consumer and produced with greater environmental responsibility. Food fermentation is an ally of this consumption pattern because it is a widespread food transformation process that is capable of improving the nutritional quality of the product. The present work aimed to study the fermentation kinetics of two consortia of fungi and bacteria, kefir and kombucha, investigating its symbiotic potential in cashew nut beverage, a known Brazilian feedstock consolidated in the market. The beverage was formulated with water and 10% of dried raw cashew nuts, pasteurized by HTLT method and, after this, three samples were formulated: LC-F that received inoculum composed 100% of kefir, LC-B inoculated with 100% kombucha, and LC-FB with 50% kefir and 50% kombucha. The samples were analyzed with 0, 4, 8, 12, 24, 36, 48 and 72 hours of fermentation at 28 ºC. In vitro experiments were conducted for pH, soluble solids, titratable acidity and determination of sugars and organic acids, while in vivo experiments tested acute toxicity and changes in the locomotor activity of zebrafish. In all in vitro assays, LC-B showed slower changes over time while LC-F and LC-FB not only showed higher speed in their reactions but also showed similar curves in their dynamics. In all samples, pH and soluble solids reduced while titratable acidity increased. LC-F and LC-FB exhausted their carbohydrate reserves within 48 hours, but LC-FB was more efficient in the consumption of oligosaccharides. No symbiotic action was observed between kefir and kombucha associated with optimization of the functional organic acids production. LC-FB and LC-B reduced the animal’s natatory capacity, suggesting probiotic action, but the faster hydrolysis of sugars in LC-FB might be associated with the animal’s higher mobility at 72 hours. No sample at any time presented acute toxicity. Finally, it was found that the mixture of kefir and kombucha presents more efficient sugar hydrolysis dynamic, including larger molecules, but requires further investigation to confirm probiotic activity.