Potential of near infrared transflectance spectroscopy to detect adulteration of Irish honey by beet invert syrup and high fructose corn syrup

Near infrared (1100-2498 nm) transflectance spectroscopy was used to detect beet invert syrup (BI) and high fructose corn syrup (HFCS) adulterants in artisanal Irish honey. The sample set investigated comprised authentic (n = 83), BI-adulterated (n = 56) and HFCS-adulterated (n = 40) honeys. Soft independent modelling of class analogy was used to classify honeys as authentic or adulterated while partial least squares regression (PLS1) was used to predict the adulteration level. Spectral data were investigated in three forms: raw, after multiplicative scatter correction and after second derivative transformation. The best classification model was obtained using raw spectral data. The preferred models for prediction of percentage adulteration involved PLS1 of multiplicative scatter corrected spectra (adulteration with BI) and second derivative transformation (adulteration with HFCS). The present study has demonstrated that near infrared spectroscopy could be used as a rapid screening tool for detection of BI and HFCS adulteration in Irish honey.