Effect of redio frequency heating as a potential quarantine treatment on the quality of 'bing' sweet cherry fruit and mortality of codling moth larvae

Authors: MONZON, MARIA - UC DAVIS; BIASI, BILL - UC DAVIS; SIMPSON, T - UC DAVIS; Johnson, Judy; FENG, X - UC DAVIS; SLAUGHTER, D - UC DAVIS; MITCHAM, ELIZABETH - UC DAVIS

Submitted to: Postharvest Biology and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/31/2005
Publication Date: 3/10/2006
Citation: Monzon, M.E., Biasi, B., Simpson, T.L., Johnson, J.A., Feng, X., Slaughter, D., Mitcham, E.J. 2006. Effect of redio frequency heating as a potential quarantine treatment on the quality of 'bing' sweet cherry fruit and mortality of codling moth larvae. Postharvest Biology and Technology. 40:197-203. http://handle.nal.usda.gov/10113/7415.

Interpretive Summary: 'Bing' sweet cherries must be fumigated with methyl bromide as security against codling moth infestations for shipment from the U.S. to certain international markets. Methyl bromide fumigation can result in negative effects on cherry quality, especially stem color. In addition, regulatory and economical concerns regarding the future use of methyl bromide as a postharvest fumigant have increased interest in alternative quarantine treatments. Radio frequency (RF) energy is a potential alternative because it rapidly heats cherry fruit, providing insect mortality without adversely affecting fruit quality. This study evaluates the effect of RF treatments on codling moth mortality and fruit quality. Cherry fruit were heated with RF energy to four target temperatures between 50 and 54°C, held for various holding times, and then stored under simulated air or sea shipment conditions before quality evaluation. There was no significant affect on cherry color, decay or shrivel, and RF had only a slight affect on berry browning, showing no commercially-significant damage. Regardless of shipment, stem browning and berry pitting were affected by RF heating. Cherry quality was most affected when fruit were treated with RF and stored to simulate sea shipment. Heating the fruit to 53 or 54°C assured 100% codling moth larval mortality. Treatments that may provide quarantine security include heating fruit to 52°C and holding for 4 min, 53°C for 1.5 min, or 54° for 1 min, but quality of the cherries following these treatments was only acceptable when fruits were stored to simulate air shipment.

Technical Abstract: 'Bing' sweet cherry (Prunnus avium L.) fruit quality and codling moth (Cydia pomonella [L.]) fifth-instar larval mortality were evaluated after radio frequency (RF) heating. The fruit were heated with RF energy to four target temperatures (50, 52, 53, and 54°C), held in the hot water for various holding times from 0.5 to 6 min, and stored under simulated air or sea shipment conditions (5°C for 24 h or 0°C for 2 weeks, respectively) before quality evaluation. There was no significant affect on cherry color, decay or shrivel, and RF had only a slight affect on berry browning, showing no commercially-significant damage. Regardless of shipment, stem browning and berry pitting were affected by RF heating. Cherry quality was most affected when fruit were treated with RF and stored to simulate sea shipment. Heating the fruit to 53 or 54°C assured 100% codling moth larval mortality. Treatments that may provide quarantine security include heating fruit to 52°C and holding for 4 min, 53°C for 1.5 min, or 54° for 1 min, but quality of the cherries following these treatments was only acceptable when fruits were stored to simulate air shipment.