Keeping Qualities of ‘Stayman’ and ‘Delicious’ Apples Treated with Calcium Chloride, Scald Inhibitors, and other Chemicals1

Abstract

‘Stayman’ apples (Malus domestica Borkh.) dipped in 4% CaC12 were firmer after 5–6 months storage in air at 0°C and developed less senescent breakdown than untreated fruit. Use of the thickener Keltrol with CaC12 or vacuum infiltrating (VI) CaC12 resulted in the firmest fruit after storage and the highest flesh Ca levels. ‘Stayman’ stored 5 or 6 months in CA at 0°C were 1.5 kg firmer than air-stored fruit. Dipping apples in CaC12 prior to CA storage provided little additional benefit. Liquid concentrate formulations of diphenylamine (DPA) and ethoxyquin used alone or in combination with 4% CaC12 gave excellent scald control on ‘Stayman’ stored 5 or 6 months at 0° + 6 days at 20°. However, the same chemicals gave poor scald control for ‘Starkrimson Delicious’ picked early to midseason. The antioxidants BHT and BHA evaluated as postharvest dips at 2,000 ppm were less effective than DPA or ethoxyquin in controlling scald on ‘Stayman’. ‘Delicious’ apples were not significantly firmer after 6 months storage in air at 0°C when dipped in 3% CaC12 alone or with Keltrol, or when CaC12 was VI. When CaC12 was contaminated with Penicillium expansum spores, VI of the solution greatly increased decay of both ‘Delicious’ and ‘Stayman’.

Effects of “Rapid CA”, High CO2, and CaCl2 Treatments on Storage Behavior of ‘Golden Delicious’ Apples1

“…The beneficial effects of Ca treatments on firmness retention in air or slow CA stored fruit (Table 5) substantiate the results of previous studies (1,2,6,9,10,12,13). However, little or no benefit was observed with rapid CA or high C 0 2 + rapid CA storage techniques, provided that no delays in storage were encountered (Tables 3, 4, 5).…”

“…The use of high C 0 2 treatments prior to controlled atmosphere (CA) storage (3,11), postharvest CaCl2 treatments (1,2,6,9,10,12,13), and a " rapid CA" procedure (5,8,15,16,17) have reduced the rate of softening in stored apples. Although rapid CA can effectively control softening in 'Golden Delicious' apples grown in British Columbia (8), the effects of prestorage high C 0 2 and Ca treatments in conjunction with rapid CA were not fully understood.…”