Authenticity of speciality sugars – Determination of carbohydrate source and geographical origin of invert sugar syrup and burnt sugar syrup

Abstract

Modern instrumental analytical methods for the determination of 13C/12C ratios are established to differentiate between metabolic products of C3 and C4 plants. Differentiation and identification of sucrose from pure beet (Beta vulgaris) and pure cane (Saccharum officinarum) are possible without doubt. Influenced by the worldwide hydrological cycle the determination of the isotope ratios of 2H/1H and 18O/16O as well as their variations provide information about geographical origin. Using samples of selected crystal cane sugar (CCS) with known origin, invert sugar syrups (ISS) as well as burnt sugar syrups (BSS) produced therefrom, the authenticity was determined. The speciality sugars ISS and BSS which were made from CCS could be identified as carbohydrates of C4 plants by using 13C/12C Isotope-Ratio Mass Spectrometry (IRMS). In combination with yeast fermentation of ISS and sugar separation from BSS and fermentation into ethanol as well as knowledge about production water, the C2-H/O isotope ratios of ethanol can theoretically determine the geographical origin of the sugars.