• Journal of the East Asian Society of Dietary Life
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• v.14 no.4
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• pp.343-347
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• 2004

Abundant amounts of unripe apples, which were picked out before maturation, were abolished every year fer wastes. Since unripen apples are known to be rich in functional components, the ultimate objective of this research was to utilize them for food resources. The concentrations of polyphenols in hot water extract were the lowest, those in 75% acetone extract the highest. Concentrations of polyphenols in 5/30 sample were 3.5 times higher than those in 6/30 sample regardless of solvents used for extraction. The degree of condensation of flavanolic tannins in the peel was lower than those of the other parts, and the hot water extract was more condensed than the acetone extract. The amount of total flavonoids in the peel and 5/30 samples were 2.7 and 5.0 times higher than those of the flesh and 6/30 samples, respectively.

• Journal of the Korean Home Economics Association
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• v.19 no.4
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• pp.33-39
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• 1981

This study was attempted to determine the pectin contents of various fruits(Cherry, strawberry, plum, peach, apricot, apple, crabapple) and to investigate the changes in the properties of pectin and pectin gel during crabapple ripening. Methoxyl content, molecular weight and intrinsic viscosity were measured in ripened and unripened crabapples. In order to determine the characteristics of pectin gel, percent sag was measured by exchange Ridgelimeter, hardness and textural characteristics of jellies were measured by a penetrometer and a texturometer. The experimental results are summarized as follows: 1. The pectin contents of various fruits were 1.16% for cherry, 3.17% fir strawberry, 4.29% for plum, 5.51% for apricot, and pectin contents of peaches and apples varies depends on varieties from 4.54% to 5.61% to 6.52, respectively. The pectin contents of unripened and ripened crabapple wee 9.21% and 9.84% respectively, indicating that pectin content increased with fruit maturity. 2. The methoxyl contents, which was 6.61%~6.95%, was very low and it increased significantly during fruit ripening. Further, a decrease in acetyl content, intrinsic viscosity, molecular weight occurred during the ripening of crabapples. 3. The percent sag of crabapple jellies increased with fruit maturity from 5.26% to 5.79%, and the corresponding jelly grade decreased in ripened crabapple. 4. The hardness of jellies determined by a penetrometer was 79.15 pp.U. for ripened crabapple jelly, 90.62 pp.U. for unripe ned crabapple jelly. 5. In the textural characteristics of gels measured by a texturometer, the gels made from unripened crabapple were shown to have the highest values in hardness, cohesiveness, adhesiveness and gumminess.