Estudio de la inhibición del pardeamiento enzimático por irradiación y de la calidad poscosecha durante el almacenamiento refrigerado de la naranjilla (Solanum quitoense Lam.) irradiada

Abstract

The inhibition of enzymatic browning by irradiation and postharvest quality at refrigerated storage was studied in naranjilla (Solanum quitoense Lam.) irradiated. The naranjilla juice, variety INIAP Quitoense-2009 harvested at physiological maturity (75% of yellowing) was used in experimental development. The physical, chemical and biochemical properties of the naranjilla juice in the dose range 250 to 3000 Gy were evaluated. The irradiated naranjillas stored up to 60 days at 8 ° C and 90% RH, by sampling every 15 days over a time of 7 days storage at 20 ° C and 80% RH to simulate the time shelf life, and was determined firmness, pH, SST (° Brix), titratable acidity, weight loss (%) enzyme activity of polyphenol oxidase (PPO), sensory quality and appearance of the fruit. Naranjilla was used as a control without irradiation. Finally he raised a basic design for pulping frozen naranjilla, which included irradiation unit operation as an alternative to mitigate enzymatic browning in the pulp. It was determined that the dose of 500 Gy preserves the characteristics of the naranjilla and inhibits PPO activity in 38.37%. During postharvest study, treatment with gamma radiation inhibited the enzyme activity by 29.31%, finding no statistically significant differences in pH, TSS, titratable acidity and weight loss; although there were a total loss of firmness of the treated naranjilla. The naranjilla irradiated at a dose of 500 Gy can be processed to obtain a frozen naranjilla pulp that would meet the physical, chemical and sensory requirements of the Ecuadorian technical standard INEN 2337: 2008, for fruit pulps.