Comparison of Various Signal Processing Techniques and Spectral Regions for the Direct Determination of Syrup Adulterants in Honey Using Fourier Transform Infrared Spectroscopy and Chemometrics

Gerard Dumancas,Helena Ellis,Jossie Neumann,Khalil Smith

doi:10.3390/chemosensors10020051

Gerard Dumancas, Helena Ellis + Show 2 more

Open Access

https://doi.org/10.3390/chemosensors10020051

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Abstract

Honey consumption has become increasingly popular worldwide. However, the increase in demand for honey has also caused an increase in its adulteration, a deliberate fraud which involves adding of other substances to pure honey for economic purposes. This process not only lowers the quality of honey, but also has potential health risks, including high blood sugar, increased risk of diabetes, and weight gain. Herein, we develop an easy-to-use and direct method of quantifying corn, cane, beet, and rice syrup adulterants in honey using Fourier transform infrared spectroscopy and chemometrics. Various signal processing techniques, including derivatives, moving average, binning, Savitzky–Golay, and standard normal variate using the entire spectral region (3996–650 cm−1) and specific spectral region (1501–799 cm−1), were compared. Optimum results were obtained using first derivative signal processing for both the entire and specific spectral regions. The first derivative signal processing technique garnered the most optimum results using the specific spectral range (1501–799 cm−1) (RMSECVaverage = 0.021, RMSEPaverage = 0.014, R2average = 0.859) across all syrup adulterants. An exploratory analysis to assess the utility of this specific spectral region in pattern recognition of samples based on their adulterant content show that this region is effective in discriminating samples according to the presence or absence of honey syrup adulterants.

Highlights

Honey is a thick, sugary, concentrated nectar that is made up of approximately 18%water
We explored the utility of a Fourier transform infrared spectroscopy with attenuated total reflectance accessory (ATR-FTIR), which harbors the mid-IR region, and the partial least squares (PLS) chemometric technique to simultaneously determine the concentrations of corn, cane, beet, and rice syrup adulterants in honey
Subtle spectral differences were evident in the fingerprint region (1501–500 cm−1 ) in both the training and testing sets due to variations in the concentrations of the corn, cane, beet, and rice syrup adulterants (Figures 1 and 2)

Summary

Introduction

Sugary, concentrated nectar that is made up of approximately 18%water. Sugary, concentrated nectar that is made up of approximately 18%. The assessment of honey safety and quality is not regularly monitored. In the case of honey, adulteration is the addition of any substance to the pure honey. Adulterants most frequently added to honey include syrups of corn, cane, beet, and rice, which have economic and organoleptic consequences. Adulterated honey poses risks to consumer health, such as higher blood sugar and weight gain. Due to the decline in honey quality, consumers have perceived low confidence in the nutritional value this product brings, making its marketing to the public more challenging [1]. Honey evaluation would help to improve the quality of honey, and assist in improving its appeal to the public

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