Conservação de pêssegos em sistema refrigerado convencional, atmosfera controlada e dinâmica

Abstract

The peach fruit (Prunus persica (L.) Batsch) have great economic impact worldwide but are characterized by high perishability and short life in the market, presenting a climatic increase in ethylene production and in the ripening rate. To increase the useful life of these fruits, refrigerated storage is necessary, as this may present some limitations, it is essential to use other technologies such as controlled atmospheres, which were conventional, ultra-low oxygen and dynamic. Through this work, you can evaluate storage systems refrigerated in controlled atmospheres, atmosphere controlled ultra-low oxygen atmosphere and controlled by maintaining quality peaches, for different storage periods, as well as the response of these fruits to the fluorescence sensor stressed by the reduction of oxygen. 'Jubileu' peaches were stored and evaluated at 0, 10, 20, 30, 40 and 50 days, simulation for 24h at 20 °C; 'Sensação' peaches were stored and evaluated at 0, 15, 30, 45 and 60 days and simulation for 24 h at 20 °C and 'Olímpia' peaches were stored and evaluated at 0, 12, 24, 36 and 48 days and simulation by 48h at 20°C. The fruits were subjected to the following atmospheric concentrations: 20-21% O2 + 0.03-1% CO2 in a refrigerated atmosphere (RA); 1% -2% O2 + 10-11% CO2 in a controlled atmosphere (CA); 0.5-0.6% O2 + 4- 5% CO2 in controlled atmosphere of ultra-low O2 (ULO) and 0.4-0.5% O2 + 10-11% CO2 in dynamic controlled atmosphere (DCA) (with sensors fluorescence). The temperature of 1 ºC and relative humidity of 90-95% was kept constant in the cold chambers. The quality parameters were evaluated: total soluble solids, hydrogen potential, titratable acidity, total soluble solids ratio by titratable acidity, pulp and epidermis firmness, weight loss, total phenolic compounds, antioxidant activity, total carotenoids, rot incidence, parameters color, ethylene; acetaldehyde and ethanol. Analysis of variance, Tukey test, regression and multivariate analysis were performed. The three experiments showed a high percentage of mass loss in RA, decreased ripening progress through physical-chemical parameters, such as SST, AT, °HueE, °HueP, FP in AC, ULO and ACD, more accentuated presence of acetaldehyde and ethanol and ethylene reduction in AC and ACD. Phytochemicals such as AA, CFT and CT underwent few changes during storage in the three systems. The 'Sensação' and 'Olímpia' peaches responded to the fluorescence sensor when subjected to oxygen stress. The 'Jubileu' fruits maintained the best quality parameters for up to 50 days in CA. With the factor analysis in ‘Sensação’, the variables ethylene, mass loss, pulp firmness and total soluble solids were identified as the most important in this experiment. The peach cultivar 'Olímpia' at 48 days showed sensitivity to cold injury, with browning of pulp in all storage systems.