RESPIRATION AND RELATED PARAMETERS OF MATURATION IN HARVESTED Chicozapote IN THE YUCATAN PENINSULA

The sapodilla is a fruit native to America, considered to be originated from the Yucatan Peninsula. It is classified as a climacteric fruit, whose ripening process depends on external factors that induce the production of ethylene. In the biosynthetic pathway of ethylene, ACC oxidase enzyme is responsible for the oxidation of ACC to ethylene, which is the last stage of its biosynthesis. Because the metabolic processes related to the respiratory process of the fruit during postharvest maturation are still unclear, the aim of this work was to study the main changes in respiration and related parameters during ripening. Sapodilla (Manilkhara achras) season fruits were harvested in the experimental field of the National Autonomous University of Chapingo in Yucatan and allowed to ripen at room temperature (28 +/- 2 degrees C), evaluating the rate of CO(2) and ethylene production in whole fruit, destroying six of them each day, to perform the determinations in the pulp. The results indicated that for the selection sapodilla fruits Campeche, grown in Yucatan, the climacteric peak occurs around the fifth day after harvest and coincides with a peak of ethylene and the maximum activity of the enzyme ACC oxidase. The PPO enzyme uses as substrate the anthocyanins and tannins. Ethanol appears as a breakdown product and not as a substrate for the synthesis of ethylene. Anthocyanins and acetaldehyde in the edible pulp of this fruit, during the maturity and senescence, contribute to its color.