Studies on Fermentative Processing of Apple Fruit

Part XIII. Factors affecting the effects of maceration of milled apple pulp in cider-making

Abstract

Maceration treatment of milled apple pulp in cider-making has some effects on the composition of the resulting juice and cider. Influences of maceration conditions on these effects were studied. With grated apple pulp, as compared with crushed pulp, only little decrease in malic acid content was caused during maceration, unless highly aerobic conditions, such as a large superficial areain contact with air, were provided. Extended duration of maceration largely decreased the malic acid content, but was liable to give unpleasant flavour and taste to the cider. Addition of sulfur dioxide up to 100ppm inhibited the malic acid decrease and lactic acid increase, but did not inhibit the succinic acid increase. Malic acid decrease was accelerated by warming the pulp. By cooling to 5°C the malic acid decrease was retarded and the volatile acidity of the juice was considerably increased. When flozen at -18°C, however, a rapid malic acid decrease occured after thawed. Tannins did not decrease during maceration with Jonathan variety apples, except when the pulp was treated highly aerobically or treated by freezing-thawing. The use of grated pulp and addition of sulfur dioxide appreciably increased the tannin contents.