EFFECTS OF TOTAL SOLUBLE SOLIDS, PH AND SACCHAROMYCES CEREVISIAE DENSITY ON THE QUALITY OF LONGAN WINE

Abstract

Two trials were conducted to investigate the effects of total soluble solids, pH and Saccharomyces cerevisiae density on the quality of longan wine. Longan juice was added to sucrose and citric acid at  different concentrations to attain samples of total soluble solid concentration and pH in the range of 21 - 25oBrix and 4.0 – 4.6. All the samples were innoculated with Saccharomyces cerevisiae (initial populations of yeast raging from 105- 107 cells/ml). The results showed that the oBrix of 23%, with a pH of 4.3 and yeast density of 106 cells/ml was ideal to be applied in longan winemaking. After 7 days of fermentation, the amount of total alcohol of the end product was 13.87%, with 2.69% reducing sugars remaining, a pH of 3.61, and oBrix of 6.22%. Sensoryevaluation was found to meet consumers demand for quality and also, the sulfur dioxide and methanol concentration of the wine met the Quality Standards in Vietnam (QCVN 6-3:2010/BYT).