El riego deficitario controlado mantiene la calidad de la nectarina extratemprana mínimamente procesada

Abstract

Due to aridity and scarce water resources in the Mediterranean agricultural systems cultivation should be based on deficit irrigation strategies (DI). This work studies the effects of DI on minimal processing of white flesh extra early picked ‘Viowhite’ nectarine. Three types of irrigation were established: Control, watered at 100% of crop evapotranspiration (ETc); Overirrigated, watered at 120% of ETc; and DI, watered as Control, except during the phases I and II of fruit growth and after harvesting, when the trees were irrigated at 80 and 60% of Control, respectively. Harvested fruits at commercial ripening stage were cut in 6-8 slices and packaged in hermetically sealed polypropylene trays for generating a passive modified atmosphere of around 15.5 kPa O2 and 3 kPa CO2. Trays were stored up to 8 days at 5°C. Initially, the soluble solid content from DI nectarines was significantly higher than in T and S fruits (9.97 ± 0.20 vs. 8.57 Brix) but after storage no significant differences were found. The pH (3.32 ± 0.01) and titratable acidity (0.38 g citric acid/100 f.w.) was similar in all irrigation treatments. After 8 days, the DI slices had a value of vitamin C slightly higher than the other irrigation treatments (15.62 ± 0.60 vs. 14.20 ± 0.11 vit C/100 g f.w.). No pathogenic bacteria were detected and psychrophilic counts were < 2 log cfu g-1 for the DI and between 2.4 to 2.6 log cfu g-1 in S and T treatments. Browning and dehydration was developed in all treatments, reducing the sensorial quality. The final sensorial values ranged from 5.17 to 5.50, above the limit of commercialization. In conclusion, the application of DI enabled savings of approximately 3,282 m3 of water, did not negatively affect the quality of nectarine slices, allowing a fresh-cut product with a shelf life of 8 days at 5 °C.