Isolation, screening, and application of aroma-producing yeast for red dragon fruit wine

Nineteen yeast strains were screened from the soil, dead branches, and fruit peels of a dragon fruit orchard. The yeast strain Z03M was obtained through preliminary screening, rescreening, and sensory flavor evaluation. This strain has certain alcohol-producing characteristics and good aroma-producing performance. Based on morphological and molecular identification, it was identified as Pichia kudriavzevii. The differences in flavor in dragon fruit wine from natural fermentation, inoculation with strain Z03M, commercial yeast, and mixed fermentation were comprehensive analyzed and compared via high-performance liquid chromatography, gas chromatography-mass spectrometry and gas chromatography-ion mobility spectroscopy. During the fermentation process of dragon fruit wine, We found that strain Z03M preferentially utilizes glucose. Malic acid and lactic acid are the main organic acids found in dragon fruit wine. The relative contents of volatile flavor compounds such as alcohols, aldehydes, terpenes, and heterocyclics of dragon fruit wine fermented with strain Z03M were 71.11%, 4.34%, 0.32%, and 1.78%, respectively, which were significantly higher than those of the other fermented samples. Among them, the content of 3-methyl-1-butanol was high, providing a banana aroma to the dragon fruit wine. Additionally, the wine fermented by a mixture of strain Z03M and commercial yeast had a high content of ester compounds, indicating that mixed fermentation can improve the flavor quality of dragon fruit wine. The results of this study have the potential value for the production of dragon fruit wine and for the research and development of dragon fruit products.