Physical and chemical study of minimally processed products of 'Pérola' pineapples

The aim of the present study was to determine the physical and chemical characteristics of minimally processed products of 'Pérola' pineapples, "roundels" and "halves," stored under different temperatures (3ºC, 6ºC and 9ºC). The fruits, selected according to degree of maturation and absence of injury, were washed, disinfected with chlorine (200 mg.L-1) and stored at 10ºC for 12 h before processing. The minimally processed product was packaged in styrofoam trays covered with a stretchable PVC film ("halves") or in polyethylene terephthlate trays ("roundels") and stored under refrigeration. The product was then examined every 3 days with regard to texture, coloration, pH, and contents of total soluble solids, total titratable acidity, ascorbic acid and soluble and reducing sugars. During the storage, the product became less firm and its pulp appeared dark. The contents of the soluble and reducing sugars and total soluble solids weren't affected by the type of preparation, temperature or packaging. The levels of total titratable acidity increased and were influenced by the temperature, with those products kept at 9ºC showing the highest levels, resulting in a decrease in pH. The products stored at 9ºC also showed a more rapid development in the dark, in the reduction of the level of ascorbic acid and a shorter shelf life (6 days), while for those stored at 3ºC and 6ºC this period was 9 days. From the results obtaineds, it could be concluded that the storage temperature is a limiting factor for the shelf life of these products.

Ananas comosus; storage; preparation; refrigeration