Submitted to: Postharvest Biology and Technology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/4/2004
Publication Date: 3/6/2005
Citation: Fan, X., Sokorai, K.J. 2005. Assessment of radiation sensitivity of fresh-cut vegetables using electrolyte leakage measurement. Postharvest Biology and Technology. 36: 191-197. Interpretive Summary: Consumption of fresh-cut vegetables (salad greens) in the USA has increased in recent years. Although the prevalence and the contamination level of food-borne human pathogens in fresh-cut vegetables are low, there is a concern over the microbial safety of fresh-cut vegetables. Ionizing radiation is a non-thermal technology that eliminates food-borne pathogens and extends the shelf-life of fresh fruits and vegetables. The tolerance of many common fresh-cut vegetables to irradiation is unclear. This study was conducted to investigate the radio-sensitivity of thirteen common fresh'cut vegetables using a tissue electrolyte leakage measurement. Our results showed electrolyte leakage increased linearly with higher radiation dose for all vegetables, indicating the measurement can be used for assessment of radiation sensitivity. The findings should help fresh-cut industry to select suitable radiation doses for different vegetables for the purpose of food safety enhancement.
Technical Abstract: A study was carried out to assess the use electrolyte leakage measurement to evaluate radiation sensitivity of thirteen fresh-cut vegetables with varied antioxidant capacity. Fresh-cut vegetables were gamma irradiated at doses up to 3 kGy. Electrolyte leakage of the samples was measured. Electrolyte leakage increased linearly with higher radiation dose for all vegetables. The radiation dose threshold, defined as the dose at which a significant (P<0.05) increase in electrolyte leakage was observed, varied among vegetables, ranging from 2.44 kGy for broccoli to 0.60 kGy for carrots. The radiation sensitivity had no significant correlation with endogenous antioxidant capacity or phenolics content of the vegetables, which showed large variation among the samples. Radiation dose threshold may be a useful predicator of a given product's ability to tolerate irradiation.