Iogurte caprino sabor goiaba suplementado com oligofrutose e fermentado com L. acidophilus: avaliação in vitro de potencial probiótico.

Abstract

We evaluated the survival of the starter culture Streptococcus thermophilus e o Lactobacillus delbrüeckii subsp. bulgaricus and of the probiotic Lactobacillus acidophilus in the presence of the prebiotic oligofructose when incorporated in the goat yogurt flavor guava and exposed to digestion conditions simulated in vitro. Therefore, they were processed 4 types of goat yogurt, and T1 - the yogurt added control of conventional starter culture (Streptococcus thermophilus and Lactobacillus delbrüeckii subsp. bulgaricus); T2 containing the probiotic microorganism Lactobacillus acidophilus (AT-5) in addition to the starter culture; T3 composed of oligofructose prebiotic, besides the starter culture and T4 containing the probiotic and prebiotic associated (symbiotic yogurt), as well as the starter culture. Potential tests probiotic in vitro consisted in evaluating the protective effect of the matrix comprising the yogurt and stimulating action of prebiotic fiber on the viability of probiotic bacteria tested against the simulated gastrointestinal conditions: mouth (artificial saliva), esophagus, stomach (artificial gastric juice), duodenum (artificial intestinal juice) and ileum after 7 days of refrigerated storage. From the results it was found that the yogurt control added of the starter culture when exposed or not exposed to simulated conditions of the gastrointestinal tract showed counts below the recommended for this type of product and when added to the oligofructose prebiotic, it was noticed an increase in these scores suggesting that oligofructose stimulated growth of the starter culture stimulating the viability of micro-organisms in yogurt even when exposed to the conditions simulated in the gastrointestinal tract. However, added probiotic L. acidophilus yogurt (LA-5) in the presence or not of oligofructose, there was a downward trend in counts of this micro-organism, suggesting that the prebiotic did not protect both studied strain. It is stressed that the end of the digestion, although the probiotic bacteria tested in yoghurt, both in the absence and in the presence of oligofructose, have reached the intestine in amounts lower than recommended, these counts are sufficient to adhere to the intestinal wall, colonize the intestine effectively and thus exert their biological activities, demonstrating as well as a product with probiotic potential and vehicle for carrying both lactic bacteria studied as the prebiotic ingredient in question.