ปัจจัยที่มีผลต่อปริมาณเมทิลแอลกอฮอล์และคุณภาพของไวน์หม่อน Morus alba L. / ภัทราภรณ์ ศรีสมรรถการ = Factors affecting methyl alcohol content and quality of mulberry Morus alba L. wine / Pattharaporn Srisamatthakarn
Mulberry (Morus alba L.) is the fruit which has high trend for making fruit wine, due to its deep red color, strong aroma, and good taste. From the preliminary study, it was found that mulberry wine has quite high methyl alcohol (MeOH) content. In Thailand, factors affecting the formation of methyl alcohol during fruit wine making was not yet studied. In this research, the factors of total acidity (TA), as citric acid, in must (0.4 and 0.6 %), content of pectinase enzyme (110, 130, and 150 mg/kg) and step of enzyme addition (in must ;M , and after fermentation, YW) were studied. The Inszen mulberry, Chinese variety, was used. The chemical content are as follows: 78.55% moisture, 2.59% protein. 0.27% fat, 0.86 % ash, 1.39% crude fiber, 17.18% carbohydrate, 0.46 % pectin, TSS 18 0Brix, 15.32% reducing sugar, 0.44% total acidity, pH 5.11, 2444.201 mg/L phenolic compounds (PC), 550.89 mg /L anthocyanin (ACy), 6.0 PMU/ml pectinesterase activity and 1.28 PGu/ml polygalacturonase activity. The results showed that MeOH formation in mulberry wine was influenced by all three main factors. The must of 0.4% TA affected to the formation of higher MeOH content than that of 0.6 %. Addition of pectinases in M tended to produce higher MeOH content than YW. The content of pectinase adding of 130 mg/kg induced higher MeOH formation in mulberry wine than that of 110 and 150 mg/kg. Furthermore, some physicochemical properties of mulberry wine were influenced by all three main factors, as well. Phenolic compounds, AC, ester, TSS, TA, free and bound SO2 and wine clarity were higher in the wine of 0.6% TA must than that of 0.4%. The phenolic compounds, ACy, volatile acidity, ester, wine clarity and bound SO, in mulberry wine of M were higher than YM. Adding 150 mg/kg of pectinase produced the highest PC, ACy, Hue, acetaldehyde, ester, and clarity of mulberry wine. content was not influenced by all main factors i.e. total acidity in must, step of enzyme and content of pectinase enzyme. There was no significant difference (p>0.05) in the mean scores for sensory evaluation due to all main factors except only the aftertaste was influenced by TA of the must. The wine of 0.4 % TA must got higher mean scores than 0.6% TA must. However, all mulberry wme treatments were evaluated as very good to extremely good quality.