Desenvolvimento e avaliação in vitro de formulações nutracêuticas compostas por Lactobacillus fermentum, Quercetina e/ou Resveratrol

Abstract

The bioactive activity of polyphenols such as quercetin (QUE) and resveratrol (RES) has been recognized and studied in recent years with application in several industry segments. The combined use of these polyphenols and probiotics seems to be an advantageous strategy in relation to their potential beneficial effects on human health. Therefore, this study developed new nutraceutical formulations composed of three different potentially probiotic strains (L. fermentum 139, L. fermentum 236, L. fermentum 296), fructooligosaccharides (FOS), QUE and/or RES. It was also evaluated their stability during storage. Viable counts of L. fermentum strains and contents of QUE and RES during storage at room and refrigerated temperature and when exposed to in vitro digestion in different nutraceutical formulations were evaluated. The potential bioaccessibility of QUE and RES, the antioxidant activity and the ultrastructural aspects of nutraceutical formulations were also analyzed. L. fermentum strains had counts above 9 log UFC/g and QUE and RES contents above 200 μg/mg in the formulations immediately after freeze-drying. L. fermentum 296 was more sensitive to QUE and RES during lyophilization due to greater reductions in viable counts, indicating that a possible cryoprotective effect of QUE and/or RES in Lactobacillus strains may be strain dependent. The results of this study showed in 90 days of storage the strains of L. fermentum and the concentrations of QUE and RES showed greater reductions in formulations stored at room temperature, especially in formulations with QUE + RES. L. fermentum 263 stood out with higher counts after 90 days of refrigerated storage (>7 log UFC/g). During exposure to in vitro gastrointestinal digestion, formulations with QUE and/or RES protected L. fermentum strains better than formulations with just L. fermentum + FOS. It was also observed that part of the contents of QUE (>29%) and RES (>50%) in all formulations was bioaccessible and exhibited antioxidant properties. The ultrastructural analysis of the formulations with L. fermentum 263 + FOS + QUE and/or RES showed variations in their microstructures and indicated that the bacterial cells were incorporated into the freeze-drying matrices. In view of the results of this study, the combined use of L. fermentum, QUE and/or RES is a valuable strategy for obtaining new nutraceutical formulations with the potential to promote beneficial effects on consumers' health. The development protocol for nutraceutical formulations presented in this study was submitted for patent application at the National Institute of Intellectual Property (Brazil) under protocol number BR102019022753-2.