Studying the effect of combining two nonconventional treatments, gamma irradiation and the application of an edible coating, on the postharvest quality of tamarillo (Solanum betaceum Cav.) fruits

- Any dose above 1000 Gy would damage the fruit and decrease firmness significantly.
- With higher doses the loss of weight and the decay of firmness was slower.
- Irradiation lowered weight loss by 19%, coating by 18%, and the combination by 37%.
- Combination of the treatments had a synergetic effect on the postharvest quality.

The effect of the combination of gamma irradiation with gamma rays and a commercial edible coating, Sta-Fresh 2505, on the postharvest quality of golden-yellow and purple-red tamarillo (Solanum betaceum Cav.) fruits was studied. Irradiation and edible coating were used because these are technologies that fulfill the consumer trend to buy fresh fruits while assuring food safety and prolonging shelf life.Weight loss, pH, firmness, soluble solids content, respiration rate, pulp appearance, sensory hardness, aroma, and off-flavor were analyzed. The irradiated fruits and the irradiated fruits with edible coating were stored up to 10 weeks at 5 °C and 90% RH plus 7 days at 20 °C and 80% relative humidity (RH), to simulate shelf life. The combination of the edible coating and irradiation at 500 Gy maintained the postharvest properties of the fruit. Weight loss was reduced up to 48% compare to the control. Firmness and appearance were 70 and 40% higher than the control, respectively. The respiration rate was 30% lower than the control. The combination of gamma irradiation and edible coating had a synergetic effect on the postharvest quality of tamarillo.