Postharvest conservation of 'Pedro Sato' guavas in modified atmosphere associated or not to refrigeration

The objective of this study was to evaluate the conservation of guavas 'Pedro Sato' in two maturation stage with colors of the yellow and light-green shell, under modified atmosphere, at room temperature (25 +/- 2 degrees C and UR 65 +/- 5 %) and under refrigeration (10 +/- 2 degrees C and UR 85 +/- 5 %). After the guavas were harvested and sanitization in sodium hypochlorite 1 %, the fruits were packed in: 1) film of polychloroethene (PVC); 2) flexible packaging of low-density polyethylene (LDPE); 3) arrowroot starch of the 3 % (w v(-1)); 4) arrowroot starch 4 % (w v(-1)) and 5) without coating and then packed in styrofoam trays. For each storage condition, the experiment was conducted in completely ramdomized design in factorial scheme 5 (packing) x 2 (maturity stages) x 7 (storage time), with 7 repetitions composed by three guavas each. The green peel guavas had better potential for conservation in storage both in temperature as under refrigeration. In LDPE packaging there was a better conservation of guavas in both temperatures with minor loss of mass, SST and reducing sugar. The content of vitamin C was higher in guavas packed with PVC, in both temperatures. For the pH, there was no significant interaction nor effect of the treatments. The green skin guavas 'Pedro Sato' present better preservation potential in storage, both in room temperature and under refrigeration. In order to have lower mass loss, fruits should be sealed in PEBD, both for room temperature storage of 25 +/- 2 degrees C and UR 65 +/- 5 % or storage under refrigeration of 10 +/- 2 degrees C and UR 85 +/- 5 %. However, the storage must be done under refrigeration in order to propitiate a longer retention period.