| Summary: | 碩士 === 輔仁大學 === 食品營養學系 === 94 === The sugar content of passion fruit is determined about 16˚Brix, but it is seldom consumed directly due to higher acidity. The quality of commercial passion fruit wine and distillate spirits are diverse, and some of them are characterized with stronger alcohol flavor, cloudiness, and somber or poor flavor. The high acidity and sulfur-containing compounds contribute to the organoleptic properties of passion fruit that cause difficulty to make good quality of table wine. The purpose of this study aimed to investigate parameters for processing good quality of passion fruit wine. Passion fruit juice from Puli was employed in this study, which was separated into three must styles (supernatant, sediment, juice). Each must was adjusted its acidity to 0.7 g/100 mL and sugar content to 22°Brix, following vinified with the S. cerevisiae Fermivin at 20 °C. The optimal must style was then selected for fermentation study. The effects of different yeast strains（Lalvin V1116, Lalvin RA17, Fermivin, Danstil D）, fermentation temperature, the addition of nutrients and potassium metabisulfite were investigated. Besides, the impact of partial deacidification of passion fruit juice on the flavor of passion fruit wine was also evaluated.
Results indicated that fermentation rate of sediment was the fastest, and supernatant the slowest among the three must styles. Wine made of supernatant brought out the refreshing aroma of passion fruit, less bitter, and more acceptable. Danstil D led to a slow starting fermentation rate, and had great bitterness. The use of Lalvin RA17 resulted in a great amount of volatile acidity, and bitter taste. Therefore, Fermivin and Lalvin V1116 were selected as the starter for subsequent studies.
The passion fruit wines fermented with Fermivin at 20 °C and/or Lalvin V1116 at 25 °C were characterized with imparting refreshing fragrance of passion fruit, less bitter, and full-bodied of taste. Addition of nutrient up to 200 ppm increased the fermentation rate, and decreased the titratable acidity of wine. And the sensory evaluation on acceptance indicated that addition of 200 ppm elicited better flavor. Though, addition of 150 ppm potassium metabisulfite inhibited the fermentation starting, off-odor was found in wine products free of that. Therefore, the adequate addition of potassium metabisulfite in fermentation of passion fruit wine was 60~100 ppm.
Conclusively, more aroma and better body of passion fruit wine was obtained by the process developed in this study using calcium hydroxide or calcium carbonate for deacidification. The results of sensory ranking test showed better acceptability from the deacidified wine using calcium hydroxide. However, the consequence of consumer test revealed no significant difference in appearance, aroma, taste, and overall acceptance between deacidified（calcium hydroxide）and undeacidified passion fruit wines.
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