Effects of super O2 atmospheric storage on postharvest quality of 'Deborah' tomato

Abstract

Alternative strategies for maintaining and even increasing the postharvest quality of fresh horticultural produce with little energy consumption have gained a creasing interest of the scientific community. This interest reflexes the growing public demand for reducing the use of chemicals, increasing the length of the shelf life and the quality of fresh fruit and vegetables, and generating food with higher functional property. Recent studies demonstrated the possibility of using hyperbaric pressure (HBP) for reducing the rate of the physiological activities related to plant ripening and senescence, and increasing antioxidant compounds, natural resistance and postharvest life of fresh horticultural produce. A HBP system uses little energy for exposing horticultural produce to O2 enriched air above the ambient air standard concentration of 0,278 kg m-3 at 22°C, the standardized atmospheric pressure. Tomato cultivar 'Débora' is receiving a great Brazilian public acceptance due to its superior characteristics in terms of flavor and aroma. However, its high metabolism rate generates a very short postharvest shelf life (a few days) at ambient temperature. Given this context, the objectives of this research are: a) to determine the optimal HBP for extending the postharvest shelf life of 'Débora' tomato; and b) to determine the effects of the resultant O2 concentrations on the physiology, biochemistry and metabolisms pro- and antioxidant of this tomato cultivar. The experiments will be conducted at the Postharvest Laboratory of FCAV-UNESP, Jaboticabal, SP, Brazil, and consist on applying HBP and temperature combined treatments on industrially grown tomato at the physiologically mature stage. During the first phase of the project, the produce will be submitted to the atmospheric pressure, 100 kPa (the control sample), and at 200, 400, 600 and 800 kPa, and at a constant ambient temperature of 22°C. During the second phase of the project, the produce will be submitted at the same previous pressure, but at 12 ±2°C. The periodic measurements carried out during the treatment aim to determine the progression of the weight, color, firmness, respiration rate, ethylene production, titratable acidity, soluble solids, ascorbic acid, total antioxidant activity, total extractable polyphenols, lycopene, beta-carotene, and enzymatic activities of the treated produce. (AU)