Determining the Authenticity of Ghanaian Honeys Using Stable Isotope Ratio Analysis (SIRA)

Area of Science:

• Food Science and Technology
• Analytical Chemistry
• Environmental Science

Background:

• Honey adulteration with exogenous sugars is a significant challenge for food authenticity and consumer protection.
• Stable Isotope Ratio Analysis (SIRA) offers a robust method for verifying food product integrity.
• Ghana's honey production is substantial, making authenticity assessment crucial for its high-value market.

Purpose of the Study:

• To assess the authenticity of honey from three major Ghanaian regions using SIRA.
• To quantify the extent of C4 sugar adulteration in honey samples.
• To investigate the utility of nitrogen and sulfur isotopes in understanding regional variability.

Main Methods:

• Analyzed 28 honey samples from Volta, Bono, and Bono East regions using elemental analysis-isotope ratio mass spectrometry (EA-IRMS).
• Determined carbon (δ13C), nitrogen (δ15N), and sulfur (δ34S) isotope compositions.
• Evaluated authenticity based on AOAC Official Method 998.12, comparing bulk honey and protein fraction δ13C values.

Main Results:

• Several samples indicated C4-derived sugar adulteration exceeding the AOAC threshold, with calculated C4 sugar content ranging from 8-12% to 78-79%.
• Principal Component Analysis (PCA) effectively separated adulterated from authentic samples and highlighted regional isotopic differences.
• Nitrogen and sulfur isotope ratios provided insights into environmental and regional variations within the honey samples.

Conclusions:

• Stable isotope analysis is a highly effective tool for detecting C4 sugar adulteration in honey.
• The combined use of carbon, nitrogen, and sulfur isotopes enhances the understanding of honey's origin and authenticity.
• This study provides foundational isotopic data for Ghanaian honey, supporting its application in quality control and authenticity verification.