Effect of postharvest microwave heat treatment of pomegranate on carob moth, Ectomyelois ceratoniae, control and quality parameters

Abstract

Purpose: In some orchards in the harvest season, the pomegranates are suspected to carob moth infestation. Visible infested fruits are removed but there is a possibility of hidden infestation. The effect of microwave heating on this hidden infestation was investigated in this study. Research Method: The mature pomegranate fruits were artificially infested with the eggs or larvae (1st, 2nd and 3rd) of the carob moth inside the crown. Microwave radiation was focused on the crown zone of infested pomegranate with a novel setup and its effect on pest mortality was studied. The experiments were carried out at three microwave powers (540, 720 and 900 W) and three heating times (4, 6 and 8 minutes). In order to study the effect of microwave heating treatments on pomegranate, quality parameters including appearance, weight loss, total soluble solids (TSS), pH, titratable acidity (TA) and taste index (TSS/TA) of the samples were investigated after 60 days’ storage. Findings: The egg and larval mortality rose with microwave power and heating time. The mortality was reduced with increasing the age of pest. There were no significant differences among values of quality factors except for titratable acidity. Because of 100% mortality with no significant differences on quality parameters, 6 min treatment time with 720 microwave power was selected as the optimum treatment. Research limitations: Energy consumption in microwave heating limits the application of this method in practice. Originality/Value: Microwave local heating of the pomegranate crown is an effective novel method to remove carob moth in hidden infestation.

Keywords

• carob moth
• microwave heating
• pomegranate
• postharvest
• storage