Chemical Properties of Coconut Sap Obtained at Different Tapping Time and Addition of Preservatives

Abstract

Coconut sap is the sweet translucent substance that is derived by tapping coconut flowers commonly used as raw material of palm sugar. This tapping process is commonly conducted twice a day, i.e. during nighttime and daytime for about 15 and 9 hours, respectively. In this paper, chemical properties of coconut sap obtained during nighttime (CSN) and daytime (CSD) were measured. The preservatives used were lime and mangosteen peel powder added at concentration 0; 0.28; 0.56 and 0.84 g/L. The observed chemical properties were pH value, total soluble solids, water content, reducing sugar, sucrose, and total free amino acids content. The results of the study showed that the pH value, total soluble solids and sucrose content of CSN were lower than those of CSD. On the other hand, the water content and reducing sugar were found significantly higher amount in CSN than in CSD.  The difference of tapping time and preservative significantly affected the chemical properties of coconut sap and the palm sugar yielded. Due to the higher sucrose content and lower reducing sugar CSD was suitable as raw material than CSN to produce granulated coconut sugar. The optimum concentration of the preservatives added was 0.56 g/L.