STUDY ON THE CONDITIONS FOR CIDER FERMENTATION FROM NAM ROI POMELO (Citrus grandis L.)

Abstract

Cider is a low alcohol drink containing high nutrients, vitamins, minerals and probiotics which good for digestion and suitable for most ages. The objective of this study was to determine the raw material treatment method and to establish a fermentation process for Nam Roi pomelo (Citrus grandis L. Osbeck) cider using a commercial yeast Saccharomyces cerevisiae BV818. The factors investigated include the dilution ratio (pure and diluted 1:1), ºBrix of 10 to 20; pH of 4.0 to 5.5 with yeast concentration of 0.02 to 0.05% and fermentation time at 36 to 48 hours. The results show that fermentation from fruit juice combined with the pectinase enzyme of 0.2% (w/v) is an effective raw material treatment method. The best fermentation was done at 1:1 dilution ratio, 18 ^oBrix, pH 5.0 and yeast concentration 0.04% (w/v) with 44 h fermentation time. The product after fermentation has an ethanol content of 5.25% (v/v), light yellow and clear color, sweet and sour taste,  a specific pomelo aroma.