Discrimination of Pure and Mixture Agarwood Oils via Electronic Nose Coupled with k-NN kfold Classifier

Agarwood oils are extracted from low grade agarwood chips which are commonly processed via distillation. They can be obtained from various Aquilaria species such as A. malaccensis, A. hirta and A. crassna. This viscous oil is called as pure agarwood essential oil (100% of extracted material). Commonly, the oils are releasing long-lasting woody, warm and smoky scent due to slow release when applied to the skin. The blending of a small amount of this precious agarwood oil with other essential oils such as geranium, sandalwood, gurjum balsam, jasmine and Ylang ylang can give rich, complex and pleasant oils. Agarwood oil acts as a base note to fix the perfume odour comprising of middle and top notes. Currently, there is no scientific technique used to differentiate pure and mixture agarwood oils and usually, it is based on the different results and inconsistency from traders and buyers agreement. Thus, as part of our work on the authentication of agarwood oils from Malaysia, we propose a method to discriminate pure and mix agarwood oils via electronic nose (E-Nose) coupled with k-NN kfold classifier with accuracy percentage improvement from 90% to 100% accuracy compared to the standard manufacturer statistical tool Discriminant Factorial Analysis (DFA).