ISHS Acta Horticulturae 712: IV International Conference on Managing Quality in Chains - The Integrated View on Fruits and Vegetables Quality
TECHNOLOGICAL STRATEGIES FOR ASSURING AND MAINTAINING THE QUALITY OF MINIMALLY PROCESSED LETTUCE (LACTUCA SATIVA L.) |
| Authors: | A. Chiesa, D. Frezza, A. Leon, I. Mayorga, V. Logegaray |
| Keywords: | harvest quality, postharvest quality, nitrogen supply, ascorbic acid, fresh-cut |
| Abstract:
Development of novel approaches for assuring the quality of vegetables depends on a better understanding of the influence of preharvest factors, vegetable physiology and other functional components as affected by storage and handling. The objectives of this research includes different aspects: a) to reduce nitrate accumulation in lettuce crop cultivated in hydroponic system, b) to determine the influence of type nitrogen application in a field lettuce crop on the quality of fresh cut produce according to sowing date and genotype used, and c) to evaluate different calcium treatments as a technology to enhance the storage life of the produce. Three experiments were conducted in the Horticultural Department. Lettuce hydroponic crop were made with two nitrate-limited modified nutrient solution (100 and 50% N reduction of initial nutrient solution). Lettuce crop managed under conventional production system was carried out in open field plot of 240 m-2 during fall-winter and spring, and the treatments were vermicompost (24 kg•ha-1), 75 and 150 kg N•ha-1 applied as urea. Calcium treatments were 0 and 9 me/L in the nutrient solution of soilless lettuce crop (perlite) and after harvest lettuce leaves were dipped in CaCl2 2%. Leaves were selected, washed, weighted, packed in multilayered polyolefin bags and stored. Samples were taken at harvest and every two days for measuring general overall visual quality, color, O2 and CO2 concentrations in the packages, nitrate and calcium concentration. Both nitrate-limited nutrient solutions in hydroponic system achieved more healthy fresh cut lettuce with lower nitrate accumulation. Nitrogen fertilization increased nitrate accumulation especially in fall-winter season independently the lettuce genotype. At present, no significant differences between calcium treatments were found. | |
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