Efeito da adição de coprodutos da vinificação na atividade antioxidante de leites fermentados probióticos.

Abstract

The natural components of food sources have encouraged the development of new ingredients, resulting in the creation of new market niches. Worldwide, the interest in nutritious and healthy food products has grown, which has resulted in several researches on dairy products, among which functional products are outstanding, especially by the addition of probiotics in yoghurts and fermented milks in general. In addition to using probiotics as functional ingredients, the use of natural antioxidant ingredients has also been extensively explored in several studies around the world. Several sources of natural antioxidants are known, among them one of the most promising sources is the industrial coproducts obtained in the processing of grapes. Thus, the aim of this work was to develop probiotic fermented milks with the addition of coproducts from winemaking - grape seed and grape skin flour, to increase the antioxidant properties. The following formulations were used in the tests: 1) Control; 2) Seed 1%; 3) Seed 3%; 4) Skin 1%; and 5) Skin 3%. Probiotic viability analyzes, microbiological analyzes, physico-chemical analyzes, and total phenolic content and antioxidant activity determinations were performed. After several inoculum optimization tests, bacterial counts of probiotic cells reached values of 108 CFU/mL, above the minimum required by the legislation for classification of the product as a probiotic, which is 106 CFU/mL. The microbiological analyzes carried out on the products obtained showed results that were in accordance with the legislation. The fermentations were conducted for five hours, this time established after obtaining pH 4.79 in the Control sample. The addition of grape seed and grape skin flours in the formulations did not significantly affect the fermentation process at the concentrations applied, but rather provided an expressive increase in the total phenolic content and antioxidant activity of the fermented products, especially in the sample with addition of grape seed flour. Thus, it is possible to state that the co-products of winemaking have the potential to be used in the dairy industry as natural antioxidants for the development of functional products.