Twelve cultivars were prepared as slices and stored 12 days at 2°C. Changes in respiration and quality factors were compared. Initial respiration rates among cultivars varied from 3.5 mL CO&g/hr in Delicious to 7.6 mL CO&$hr in Monroe and decreased rapidly during the first 3 days. Idared, McIntosh, Delicious, and Rome showed relatively low respiration throughout storage. Firmness of slices during storage decreased gradually for 7 days and more rapidly thereafter. Empire, Golden Delicious, and Idared apples showed minimum changes in &miess. Change in color of slices was rapid during the first 3 davs. Cortland. Emuire. Golden Delicious. New York 674. and Deliious showed-least'brc&ing. Titratable acidity, pH, soluble solids, and weight changes during storage were small and varied by cultivar. NY674, Cortland, Golden Delicious, Empire, and Delicious showed more desirable attributes for minimal processing.

Effects of heat treatment on firmness of apples (Golden Delicious, Mclntosh and Delicious) and apple slices were studied. Heat treatment (45C, for 1.75 h) of Golden Delicious and Delicious apples significantly increased their firmness, but no sign@cant increase was observed for the Mclntosh cultivar. After storage for 7days at 2C, the treated apples were firmer than those stored at 10, 18, and 25C. Apple slices prepared from the heat treated apples were also firmer at 21 days storage than those prepared from nontreated apples: differences ranging from 12 % for Mclntosh to 48 94 for Delicious. This beneficial firming effect of heat treatment might have application in producing high quality minimally processed slices from Golden Delicious and Delicious apple cultivars.