REDUCING SCALD IN 'RED D'ANJOU' PEARS WITH HOT WATER AND REDUCED RATES OF ETHOXYQUIN

Author:	E. Curry
Abstract: The objective of this study was to investigate the use of hot water as a synergistic treatment with reduced rates of ethoxyquin as a method of controlling scald of 'Red d'Anjou' pears. Fruit from mature trees were treated with one of 4 concentrations of ethoxyquin (0, 675, 1350, or 2700 mg.l^-1) at one of 3 water temperatures (35, 45, and 55C) in a factorial design. The fruit were allowed to air dry and then placed in regular storage at OC for 6 months. After storage the fruit were held in the dark at 23C for 7 days and then evaluated for firmness, soluble solids, titratable acidity, color, and scald. In addition, a portion of fruit peel about 3mm thick was excised from the shoulder of each pear with a 15mm cork borer and extracted with 10 ml hexane for 6 hours. Absorbance at 200, 232, and 258, 268, and 280nm was measured. The hot water dip of 55C showed a slight reduction in scald compared with the two lower temperatures of 35 and 45C. Firmness increased linearly with increasing rates of ethoxyquin (r² = 0.994). At the highest temperature firmness was reduced by about 10%. Increasing temperature and ethoxyquin concentration increased the OD₂₃₂ (-farnesene) and reduced the OD_258–280 (conjugated trienes).
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