Chemometrics exploration of monosaccharides, sugar acids, stable carbon isotopes, and volatile organic compounds in Malaysian stingless bee honey from different geographical origins

Abstract

This research aimed to establish the quantification profiling of monosaccharides, sugar acids, stable carbon isotopes, and volatile organic compounds in stingless bee honey produced by Heterotrigona itama (H. itama) bee species employed with geographical discrimination study using chemometrics. In the present study, glucose (730.46–1948.99 µM) was detected in all honey samples; however, mannose (113.78 µM) and fucose (26.38 µM) were detected in only one sample (B2). On the other hand, glucuronic acid, galacturonic acid, ribose, rhamnose, galactose, xylose, and arabinose were absent in all the samples. δ¹³C values demonstrated that nectar composition in samples of this study originated from C-3 plants and no possible adulteration was deduced. Besides, a wide range of fifty-three volatile organic compounds (VOCs) was detected across the samples. The partial least square–discriminant analysis (PLS-DA) model illustrated an excellent geographical discrimination pattern of samples based on the studied variables. The PLS-DA model was validated using 10-fold cross-validation (R² = 0.84, Q²= 0.95, and accuracy = 0.93) and permutation test (p = 0.008). Variable importance of projection (VIP) exemplified thirteen VOCs (VIP > 1.4, p < 0.01) significant in the discrimination pattern and can be used as potent chemical markers. However, monosaccharides, sugar acids, and carbon isotopes were insignificant (VIP < 1.4, p < 0.01) in discriminating the stingless bee honey according to their geographical origins.