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Hydroxyl fatty acids (HFAs) are used for the production of artificial food flavorings and alcoholic beverages. In this study, we screened a series of hydroxylating lactic acid bacteria (LAB) by using a rapid screening method based on the lactonization of the products with brewing yeast. γ-Lactones have a fruity aroma with a low detection threshold, meaning that they can be readily detected by sniffing without the need for GC-MS analysis. LAB can be used to hydroxylate fatty acids, which can be lactonized with brewing yeast for detection with the sniffing method. Commercial yeast strains were cultivated in the presence of HFAs, and lactone-producing strains were detected by sniffing. Beer brewing yeast T-58 gave the highest level of γ-lactone from ricinoleic acid (>90%). Strains of LAB capable of converting unsaturated fatty acids to HFAs were screened with T-58 yeast. The Y-20 strain was determined to be the best LAB and converted oleic acid to 10-hydroxystearic acid. It was subsequently identified as Lactobacillus sakei. Notably, this LAB hydroxylated over 90% of the oleic acid in the medium at 15°C after 30–48 h. These results therefore suggest that the Y-20 strain could be used to hydroxylate fatty acids for alcoholic beverages. Keywords: Lactic acid bacteria, Hydroxyl fatty acid, Screening, Brewing yeast
