Conservação pós-colheita de alface crespa, de cultivo orgânico e convencional, sob atmosfera modificada

Abstract

Leafy lettuce is highly susceptible to water loss, which can be intensified by inadequate management of temperature and air humidity during storage and commercialization, reducing shelf life and increasing the final cost of the product to the consumer. The aim of this study was to evaluate the post-harvest quality of crisp lettuce, cv. Isabela, cultivated on conventional and organic farming, packed in different packaging and stored under refrigeration during different periods. The assay was carried out in the Universidade Federal da Grande Dourados, in Dourados, Mato Grosso do Sul state, Brazil. The experimental design was complete randomized blocks with four replications, in a factorial scheme 2×3×4: organic or conventional cultivation, three types of polyethylene packagings (fully open, partially closed and fully closed) and four evaluation periods (0; 5; 10 and 15 days). Lettuce was stored in a chamber at 5°C, relative humidity of 90%±SD, in the absence of light. We evaluated the apparent quality, fresh mass, chlorophyll content, soluble solids (SS), titratable acidity (TA) and ascorbic acid (AA). Lettuce produced in organic farming conserved for more time the apparent quality, in comparison to that produced in conventional farming, with higher values of SS and TA after storage, although with reduction of AA, but with no difference of chlorophyll loss and pH values. The fully closed packaging has proven to be more effective in reducing the fresh mass loss and to keep the apparent quality for more days.