Revestimentos comestíveis na conservação pós-colheita de tomates cv. Dominador

Abstract

The tomato is highly perishable after harvest, due the fragility of its tissues and its metabolic activity maintenance, demanding efforts in its preservation and quality. The use of edible coatings elaborated after natural and biodegradable polymers becomes an efficient alternative to increase the post-harvest duration of the fruits. Therefore, the present paper point was to evaluate the physicochemical features of tomatoes with edible coating application and submitted to different refrigeration temperatures. The tomatoes cv. Dominator were received at the Laboratory of Food Biochemistry /UEM, in January 2015, labeled as light red, selected, washed, sanitized with a sodium hypochlorite solution 1%, dried and afterwards treated with coating based in cassava starch at 2%, gelatin at 2% and pectin at 2%, and also the control group (without treatment). After each treatment was applied, the fruits stayed for approximately one hour in perforated trays for complete drying of the coatings. There were used 2 fruits for each repetition, totaling 4 repetitions for each treatment and each analyzed day. The treated fruits were split in two groups, in which the first group was kept in refrigeration, in cold chamber, 8ºC±1 (T1) during 21 days, and the second was kept in room temperature, in BOD, 25ºC±1 (T2) during 17 days. The analysis made to evaluate the tomatoes were: soluble solids (SS), pH, titratable acidity (TA), Ratio (SS/AT), ascorbic acid, peel and pulp color (parameters L*, hº, C*), overall carotenoids expressed in lycopene content, antioxidant activity (DPPH e ABTS), phenolic compounds and mass loss. For the variables: pH, titratable acidity, ratio and ascorbic acid there were significant differences between the treatments for some analysis times. For the variable, overall carotenoids expressed in lycopene content, the pectin treatment 2% showed the highest overall values at the end of the refrigeration at 8ºC. For the variables: DPPH, ABTS and phenolic compounds, the control group showed the lowest overall values at the end of the storage process. The coating based on cassava starch 2%, was the most effective in preventing mass loss and in keeping the red pulp color, at both storage temperatures. Storage temperature 8 °C provided higher post-harvest shelf life of tomatoes.