The effect of Lactobacillus plantarum LP-115 strain on improving the savor and aroma of milk containing grape sap through fermentation

Nowadays, maintaining the health of the body and choosing food and drinks with high nutritional value has become a general concern. Milk-containing grape sap (MGS) is a novel and emerging drink in countries of the world, especially Iran. Consumption of raw milk mixed with grape sap may not have a pleasant taste for some consumers. To solve this problem, mild fermentation of MGS with Lactobacillus plantarum LP-115 was proposed, which improves the drink's initial unpleasant taste and preserves the milk's enzyme balance due to heat. Gas chromatography - amino acid analyzer and mass spectrometry were used to evaluate the effect of LP-115 strain on free fatty acids (FAA) and aromatic ingredients. After 16 h of fermentation by LP-115, the MGS exhibited high levels of antioxidants (543.56 mg/L), sweet amino acids (293.47 mg/L), essential amino acids (49.66 mg/L), and unsaturated fatty acids (UFA: 2774.51 mg/L), according to the results obtained. The results indicate that increased levels of umami and sweet compounds, as well as UFAs, enhanced the aroma and functional properties of the fermented MGS. Additionally, the study found that reduced aldehyde levels and increased ketone, ester, acid, and alcohol levels contributed to the improved flavor quality of MGS. This study establishes a theoretical foundation for the industrial-scale production of fermented MGS.