Comparative study of fat properties and phenolic contents of fermented rambutan (Nephelium lappaceum L.) and pulasan (Nephelium mutabile Blume) seeds

Abstract

Rambutan and pulasan seeds are usually discarded as waste. However, the seeds contain a significant quantity of quality crude fat. Therefore, the present work was conducted to establish and compare the fat properties, and saponin and total phenolic contents of fermented rambutan and pulasan seeds. Results showed that the crude fat yields for rambutan and pulasan seeds were 3.98 and 7.41 g/10 g, respectively. Results also showed decreases in crude fat by 41% for rambutan seeds, and 23% for pulasan seeds after fermentation. The yields of the main fatty acid in rambutan and pulasan seeds, which was oleic acid, were 53.11 and 58.27%, respectively. Only 0.81 and 37.25% of triacylglycerols remained in rambutan and pulasan seed fats, respectively after fermentation. In addition, the melting temperature for both seed fats increased, while the saponin and total phenolic contents in rambutan and pulasan seeds decreased with increasing fermentation time.