Leite caprino fermentado com adição de amora-preta

Abstract

Goat milk has a chemical composition with proteins of high biological value and fatty acids that truly do benefit the human organism, not neglecting its mineral and vitamin content. It is, thus, deservedly regarded as a highly nutritional food. It does have a high digestibility rate because all fatty globules are small-sized if one compares it to bovine milk. Furthermore, they are majorly compounded by short- and middle range chains-based fatty acids. The hypersensitivity to cow milk protein is one of the main causes of food-derived allergies. Casein and alfa lactoalbumin are the chemical compounds most involved in allergic reactions. In goat milk, the deficiency of the alpha-s1 casein fraction – the main casein in cow milk – and a higher fraction of alpha-s2 casein make this milk less allergenic that might even be hypoallergenic: it becomes recommended, then, towards elderly, children and people with nutritional or gastrointestinal problems. In addition to supplying fresh goat milk, it can be ingested through the manufacture of its derivatives. Among them, fermented milk is a good option because, regardless of marketability traits, it holds onto a larger shelf life. Moreover, there is the further possibility of adding fruits and probiotic bacteria onto the mix, making it a functional food. Given the previously asserted, the aim of this study was to produce a fermented goat milk with functional characteristics by adding probiotics Bifidobacterium lactis Bb-12/Lactobacillus acidophilus LA-5, with a black berry pulp. Two treatments of fermented goat milk were produced, the first treatment (LFA) with addition of starter cultures Streptococcus thermophilus and Lactobacillus bulgaricus, plus the black berry pulp. In the second treatment (LFPA), fermented goat milk with the addition of a combination of starter culture and probiotic organisms, specifically the Bifidobacterium animalis subsp. lactis Bb-12 and Lactobacillus acidophilus LA-5, plus the black berry pulp. For the black berry pulp, the pH value was 3.311 and the acidity in percentage of citric acid was 1.26%. Regarding anthocyanins, 1614,98 mg was observed for every 100 g of cyanidin-3-glycoside and 40252,19 µg of Trolox equivalent for every 100 g of dry sample for antioxidant activity. The pH, acidity and viability of starter and probiotic organisms were evaluated for LFA and LFPA on the following days: 0, 7, 14, 21 and 35. Furthermore, physicochemical analysis of fat, proteins, carbohydrates, humidity and ash were performed, as well as sensory analysis with non-trained evaluators. Concerning pH estimates, there was a significant difference (p ≤ 0.05) between LFA and LFPA only on day 14 of storage, but acidity was higher for LFPA on days 7,14, 21 and 35. The concentrations of Bifidobacterium animalis subsp. lactis Bb-12 and Lactobacillus acidophilus LA-5 remained at high counts (> 6 Log CFU.g-1 ) during the 35 days of storage. The LFPA composition demonstrated 74.12% moisture, 4.12% fat, 3.54% protein, 18.07% carbohydrates, and 0.12% minerals. During the sensory analysis, color was the attribute with the highest average, followed by texture, overall appearance, flavor and taste. The black berry-based probiotic fermented goat milk (LFPA) showed an acceptability index of 85.5%. Regarding purchase intention, 97.5% of consumers would buy the product, indicating commercial potential. In summary, it is possible to produce a black berry-based probiotic fermented goat milk, which maintains its functional characteristics preserved during storage for 35 days and has a good sensory acceptance.