131 Controlled Atmosphere Temperature Treatments for Disinfestation of `Bing' Sweet Cherry

Abstract

Phytosanitary restrictions for insect pests can interfere with the marketing of fresh sweet cherries (Prunus avium L.). The objective of this research was to compare the quality of controlled atmosphere temperature treated (CAT) sweet cherries to methyl bromide fumigated cherries and non-heated, non-fumigated control fruit. Two CAT doses were evaluated: a 25-min exposure to 47 °C (117 °F) that heated the cherry center to 46 °C (115 °F), and a 40-min exposure to 45 °C (113 °F) that heated the cherries to a center temperature of 44 °C (111 °F). These heat doses approximated a heat dose that provides quarantine security against codling moth (Cydia pomonella Lw.) and western cherry fruit fly (Rhagoletis cingulata Lw.). An atmosphere of 1 kPa oxygen and 15 kPa carbon dioxide was established inside the treatment chamber for 21 min prior to heating. The influence on fruit quality of hydrocooling prior to the CAT treatment, cooling after treatment, and 2 weeks of cold storage after treatment in air or controlled atmosphere was evaluated. Each CAT dose was replicated four times using freshly harvested, `Bing' sweet cherries acquired from similar grower lots. Quality attributes evaluated included: stem and fruit color, firmness, soluble solids concentration, titratable acidity, decay, and sensory evaluations. Hydrocooling prior to treatment, cooling method after heating and storage atmosphere had no significant influence on cherry quality after cold storage. The stem color of fumigated cherries was less green after storage than CAT treated cherries or untreated, control cherries. Cherries heated for 25 min were rated after cold storage by untrained panelists as similar to non-heated, non-fumigated control fruit. Heated cherries and methyl bromide fumigated cherries were less firm after cold storage than control fruit.