COMBINED DEFICIT IRRIGATION AND CONTROLLED ATMOSPHERE FOR KEEPING NUTRITIONAL QUALITY IN PEACHES

摘要

Water scarcity necessitates recourse to deficit irrigation strategies (DI) for optimizing its use whilernkeeping quality of the obtained products. The effect of DI applied in two different strategies (DI 1 and DI2) onrnchanges of total phenolic contents, antioxidant capacity and vitamin C of ‘Flordastar’ peaches was studied.rnResults were compared to a Control watered at 120% evapotranspiration. After harvest, fruits were stored uprnto 14 days at 0℃ and 95% RH in air or in controlled atmosphere (CA; 3-4 kPa O_2 and 12-14 kPa CO_2),rnfollowed by 3 days at 15℃ in air (as a retail sale period). The total phenolics content was initially higher (55rnmg GAE/100 g fw) and more stable throughout postharvest life in Control than in both DI peaches in whichrntotal phenolics increased from 35-39 mg GAE/100 g fw (initial) to 61-93 mg GAE/100 g fw after 14 days ofrncold storage. Both air-stored DI peaches reached higher levels of total phenolics content than those CAstored.rnNo significant differences were found in antioxidant capacity among irrigation treatments. Air-fruitsrnshowed a growing trend throughout the experiment, while CA-fruits showed an initial growing phase andrnthen stabilized. Concerning vitamin C (ascorbic + dehydroascorbic acids; AA + DHA), initially Controlrnfruits showed higher AA than DHA content (5.43 vs. 1.28mg/100 g fw, respectively), while water stressedrnpeaches showed the opposite situation (1.86 g AA/100 g fw vs. 2.43 g DHA/100 g fw for DI_1 and 3.97 grnAA/100 g fw vs. 4.55 g DHA/100 g fw for DI_2). A general decrease in vitamin C content throughout coldrnstorage and shelf life for all treatments was found. As main conclusion, DI allowed an important waterrnsaving and provided peaches with good nutritional quality.