For the purpose of developing a high quality cider in Korea, the properties of domestic apples and cider should be analyzed to find what should be improved for betterment of cider. Fuji apples have been widely cultivated in Korea as the major apple cultivar. In this study, fermentation of cider was carried out using late harvest Fuji apples picked at December 15 by a rapid fermentation yeast strain, Saccharomyces cerevisiae SS89. Apples were crushed and filtered to prepare juice, which was fermented for 15 days with inoculation of S. cerevisiae SS89 cells. Fermentation characteristics and physicochemical properties of the cider were compared with those obtained from normal harvest apples picked at November 21.
The late harvest apples showed slightly higher values in the contents of soluble solid, reducing sugar, and total phenolic compounds. During the fermentation of late harvest cider at 20℃for 15 days, soluble solid content decreased to 4.7 °Brix from 13.6 °Brix with a decrease of reducing sugar content from 11.22% to 0.21% and an increase of alcohol content to 6.6%. Alcohol production was more rapid and the final alcohol content were higher in the late harvest cider than those in the normal harvest cider. Alcohol content reached 2.6% and 1.6% after 3 days, 6.0% and 4.4% after 9 days, 6.6% and 6.4% after 15 days during the fermentation of the late and normal harvest cider, respectively.
Analysis of the cider after filtration revealed that late harvest cider contained a slightly higher contents of alcohol, soluble solid, and total phenolic compounds than the normal harvest cider with the same level of reducing sugar content. However, the late harvest cider showed slightly lower level in the total acid, reducing sugar and DPPH radical scavenging activities than the normal harvest cider. Content of malic acid, the most abundant organic acid in cider was 0.44% and 0.49% in the late and normal harvest cider, respectively. The other organic acid contents were similar to each other. Sorbitol, glucose and fructose were detected in the cider. But sucrose was not detected. No significant differences were observed in the acetaldehyde, ethyl acetate and minor alcohols contents as well as in the Hunter color values in the two ciders. Sensory evaluation revealed that the color of normal harvest cider obtained higher score than that of late harvest. However, the score in the flavor were the same. And the score for taste was lower in the normal harvest cider than the late harvest cider.