Detecting adulteration of stingless bee honey using untargeted 1H NMR metabolomics with chemometrics

Abstract

As stingless bee honey (SBH) is gaining in popularity in the Malaysian market, it is now prone to adulteration. The higher price of SBH compared to floral honey has led to the use of unusual adulterants such as vinegar and even floral honey to mimic the unique taste and appearance of SBH. Since the current AOAC 998.12 method fails to detect these adulterants as their δ¹³C values are in the range for C₃ plants, untargeted ¹H NMR metabolomics was proposed. Principal component analysis of SBH ¹H NMR fingerprints was able to distinguish authentic SBHs from adulterated ones down to 1% adulteration level for selected adulterants. Discriminant analysis showed promising results in distinguishing the preliminary datasets of authentic SBHs from the adulterated ones, including discriminating SBHs adulterated with different adulterants derived from C₃ and C₄ plants. Hence, to assure any emerging adulterant can be detected, all ¹H NMR regions should be considered.

Keywords: Chemometrics; Honey adulteration; Metabolomics; NMR; Stingless bee honey.