Assurance that honey has not been adulterated with sugars of C4 origin (e.g. high fructose corn syrup or invert cane sugar) is carried out by the internationally recognised AOAC 998.12 C4 sugar adulteration test. In the past decade, there have been concerns around the applicability of this test to mānuka honey due to honey with a high concentration of methylglyoxal (MGO, >250 mg/kg) often failing the test. It is this same high MGO content that makes manuka honey such a premium product. This paper reviews the literature to determine possible causes for this failure and identifies more suitable methods of analysis that can be applied to detect syrup addition to manuka honey.
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