High fructose corn syrup (HFCS) was mixed with four artisanal Robinia honeys at various ratios (0–40%)
and near infrared (NIR) spectra were recorded with a fiber optic immersion probe. Levels of HFCS adulteration could be detected accurately using leave-one-honey-out cross-validation (RMSECV = 1.48;
R
2
CV = 0.987), partial least squares regression and the 1300–1800 nm spectral interval containing absorption
bands related to both water and carbohydrates. Aquaphotomics-based evaluations showed that unifloral
honeys contained more highly organized water than the industrial sugar syrup, supposedly because of
the greater variety of molecules dissolved in the multi-component honeys. Adulteration with HFCS caused
a gradual reduction of water molecular structures, especially water trimers, which facilitate interaction with
other molecules. Quick, non-destructive NIR spectroscopy combined with aquaphotomics could be used to
describe water molecular structures in honey and to detect a rather common form of adulteration