Abstract

This study was conducted to analyze the changes in the moisture and bixin levels in the seeds of Bixa orellana L. under four storage conditions: Storage without tarp (SB), storage over tarp (BD), seeds fully covered with tarp (BE) and storage in a room chilled to 4°C (OB). For 13 weeks, moisture content and bixin levels were monitored. The decreases in bixin after 13 weeks of storage at the different storage modes SB, BD, BE and OB were respectively 28.6, 25.9, 15.6 and 11.0%, while the increments in the moisture content were respectively 63.4, 57.0, 55.7 and 31.3%. No matter the storage mode, the fall of bixin was proportional to the moisture absorption. The storage mode OB brought the smallest loss of bixin and the smallest increment of moisture content, followed by BE. In tropical areas, however, the full covering of seeds with tarp would be more effective both in terms of cost and practicality. Moreover, the establishment of sorption isotherms allowed to suggest an optimal storage of the seeds of Bixa orellana L. in a dry enough environment having a relative humidity comprises between 12 and 30%.

Key words: Bixa orellana L., bixin levels, storage conditions, moisture, water activity.