Studies on the Deacidification of Black Queen Red Wine by Malolactic Fermentation

• Main Authors: Hsiao Ju- Hu, 胡曉茹
• Other Authors: Hsueh- err Chen
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/58549072485367555416

碩士 === 輔仁大學 === 食品營養學系 === 93 === The mouthfeel of high acidity and harsh flavor of Black Queen grapes grown in Taiwan due to variety and environment conditions restricts the quality of correspondent to wine products, which can not be served as table wines. Therefore, this research was aimed to improve quality of wine by deacidification via malolactic fermentation（MLF）. After the grape must fermented completely and pressed, the young wine was inoculated with the malolactic bacteria Viniflora Oenos®、Viniflora CH35®、Biolact Acclimatée®、Lalvin X-3 ®、Lactobacillus hilgardii BCRC 12937or Pediococcus pentosaceus Mees BCRC 10068 to proceed the deacidification at 20℃. According to the sensory quality of wine and the rate of the deacidification the proper strain of malolactic bacteria will be selected. By useing this bacteria the effects of fermentation conditions, ex: nutrient, temperature and Sulfur dioxide（SO2）, on the deacidification of wine were further studied. Simultaneously the physical properties and sensory quality of Black Queen red wine deacified by calcium carbonate（CaCO3）or by MLF were also compared. Subsequently, Viniflora Oenos® was selected as the malolactic bacteria for our experiments, due to its fast deacidification rate and better sensory evaluation of wine. Results indicated that lower temperature（16℃）and the presence of nutrient did not impart benefit on microbial activity. The concentration of SO2 was found to affect deacidification rate significantly. At 10 ppm SO2 the wine completed deacidification for forty days. At 30 ppm the rate of deacidification was seriously delayed. As the SO2 increased up to 50 ppm, the action was completely inhibited. Inoculation timing of Viniflora Oenos® is not influence the physical properties of red wine. Black Queen red wine which vinified in winter（12 vol %）inoculated by the lactic acid bacteria Viniflora Oenos® at the low SO2 content and 20℃, was beneficial to deacidification in sixteen days, the acidity of wine was dropped from 1.4 to 0.9 g/100ml. The results of wine deacidification with CaCO3 or by MLF showed that anthocyanins decreased as increasing pH to 3.7 in wine dealt with CaCO3. The consumer sensory evaluation also revealed that consumers have lower preference for the color and flavor of red wine with deacidification by CaCO3. Diacetyl was an important flavor and synthesized during malolactic fermentation with a buttery flavor in wine. According to the method of ASTM（E 679-79）, panel detection thresholds were found to be 1.2 mg/l in Black Queen red wine. Diacetyl resulting from Viniflora Oenos® was about of 2.4mg/L and the buttery flavor intensity is 3.22. Besides diacetyl, the wine also produces another flavor compounds during MLF. So it is worthy of further study on the compounds which influence the flavor of the Black Queen red wine in the future.