The effect of arginine addition on chemical and antioxidant properties of coconut sap during heating

Abstract

Arginine contains positive charged ends that are suitable to bind molecules with negative charge like carbonyl groups of reducing sugar in coconut sap. This research aimed to determine the effect of various arginine concentrations on chemical and antioxidant properties of coconut sap during the heating process. A 2.5 L of coconut sap was added with 0.4; 0.8 and 1.2 mM arginine and heated with an open process until the temperature of sap reached 118 C. Fifty grams of sap samples were collected in the temperature of 80, 100 and 118 C during heating treatment. The results showed that the variation of arginine concentration did not significantly affect water content, reducing sugar, total sugar, and sucrose of coconut sap samples. Coconut sap added with 0.4 mM showed the highest pH during heating. The highest of free amino acid content was shown on coconut sap added with 0.8 mM arginine at the end of heating temperature. The 0.8 mM of arginine concentration and the sap temperature of 100 C were the optimum condition to obtain the highest DPPH radical scavenging activity i.e. 69.93%, while the chelating activity of coconut sap added with 0.4 mM was significantly higher than other treatments (34.42%).