Drying of macaw palm fruits and its influence on oil quality

Abstract

After harvest, macaw palm fruits show high deterioration rates when improperly preserved. A possible cause is the high fruit water content favoring enzymatic and microbiological degradation. Therefore, this study aimed to evaluate the effect of drying on the mesocarp oil quality during storage and to set the drying curve of macaw palm fruits. For that, two experiments were carried out. In the first, the drying curve of macaw palm fruits was determined at 60 °C, and mathematical models were defined for the process. Drying was performed with freshly harvested fruits (S0) and with fruits stored for 20 days after harvest (S20). Fruits were stored for 20 days after harvested and then went through drying. The fruits were dried in a prototype dryer at 60 °C. After drying, the fruits were stored for different periods (0, 15, 30, 45, 60, and 90 days) and evaluated for oil physicochemical parameters. When compared to S0, drying of macaw palm fruits in the S20 treatment showed a lower drying time until equilibrium moisture was reached. In general, all the mathematical models tested were adequate to describe the drying process. Fruits dried at 60 °C controlled mesocarp oil acidification for up to 90 days in storage. On the other hand, drying impaired the mesocarp oil oxidative stability. We may conclude that the drying process is efficient to maintain acidity during the storage of macaw palm fruits.