EVALUATION OF AGARWOOD (AQUILARIA MALACCENIS) FROM BINTAN ISLAND BASED ON INDONESIAN STANDARD: PREDICTING ITS QUALITY USING NEAR-INFRARED SPECTROSCOPY

Abstract

The agarwood grading system in Indonesia comprises physical properties, such as colour, weight and aroma. Agarwood resin content can be a simple guide for grading agarwood quality. Thus, this research aimed to evaluate the quality of agarwood (Aquilaria malaccensis) from Bintan Island based on Indonesian standard, and to determine its resin content, using near-infrared (NIR) spectroscopy (NIRS), as a predicting model for agarwood quality. The samples were obtained from community plantation forest in Bintan island which were inoculated by Fusarium solani. Agarwood chips were graded by its colour, weight and aroma, and were converted into powder samples for colour testing and NIRS acquisition, as well as laboratory testing for resin content determination. Results, according to SNI 7631-2011, showed the agarwood quality of gubal gaharu (agar) and kemendangan (dhum) where the colour of gubal gaharu was darker than kemendangan, showing that gubal gaharu had higher resin content (24.74%) than kemendangan (12.22%). The NIR spectroscopy analysis showed that the partial least square regression (PLSR) model could be used to predict the resin content with passable accuracy.