Mass Spectrometric Determination of Cane Sugar and Corn Syrup in Maple Syrup by Use of 13C/12C Ratio: Collaborative Study

Abstract

Use of C3 carbon dioxide (CO2) fixation cycle by the sugar maple (Acer saccharum Marsh.), a dicotyledenous plant, and C4 carbon fixation cycle by 2 monocotyledenous plants, corn and cane, results in a physiological discrimination between 13C and 12C isotopes. Therefore, determination of 13C/12C ratio of maple syrup by mass spectrometry can be used to detect adulteration with cane and corn sugars. Four samples of pure maple syrup and 3 adulterated maple syrup samples were analyzed in a collaborative study. Results indicate that stable carbon isotope analysis can determine authenticity of maple products. Samples with δ13C values less negative than – 23.49%c (parts per thousand) can, with a high degree of confidence (95%), be classified as adulterated. The method has been adopted official first action.

Discrimination and classification of adulterants in maple syrup with the use of infrared spectroscopic techniques

“…Carro et al 12 used stable carbon isotope ratios to detect adulteration in maple syrup. Morselli and Baggett13 and Whalen14 developed an approved procedure for the detection of adulteration of maple syrup with 20% or more corn or cane sugars/syrups using carbon isotope analysis. Stuckel and Low15 investigated maple syrup authenticity by high‐performance anion exchange liquid chromatography with pulsed amperometric detection (HPAE‐PAD) based on oligosaccharide fingerprinting.…”

Three certified sugar reference materials for carbon isotope delta measurements

“…Carbon isotope ratio mass spectrometry (IRMS) analysis is an increasingly used tool for applications such as sugar source tracers in human diet studies 1 and food adulteration studies via the introduction of additives to food products. [2][3][4] These applications exploit the fact that assimilation of carbon dioxide by plants occurs by three different pathways. Most plants on Earth create phosphoglyceric acid as the first product of CO 2 fixation (C 3 plants) whereas some plants have evolved to synthesize oxaloacetic acid as the first product (C 4 plants).…”

“…The third pathway, crassulacean acid metabolism (CAM), evolved in a small number of plants as an adaptation to arid conditions, and is not discussed here. Carbon isotope delta, δ( 13 C) value, analysis can distinguish between C 3 and C 4 plants, [2][3][4][5][6][7][8] as the isotopic signature of C 3 plants shows a higher degree of 13 C depletion than that of the C 4 plants: C 3 plant δ( 13 C) values range between −35‰ and −21‰, while the δ( 13 C) values of C 4 plants range between −16‰ and −9‰ on the VPDB scale. 9 Many processed foods contain sugar and the δ( 13 C) values of these products reflect the dominant plant source.…”

“…Honey and maple syrups are both derived from C 3 plants and have δ( 13 C) ≈ −24‰. 2,3 These products are expensive to manufacture, resulting in higher consumer prices. High-fructose corn syrup and cane sugar (both C 4 plants), on the other hand, are more affordable alternatives to honey and maple syrup, and are used as additives to decrease the production costs of these products.…”

Comparison of FTIR, FT‐Raman, and NIR Spectroscopy in a Maple Syrup Adulteration Study

“…Carro and others (1980) used stable carbon isotope ratios to detect adulteration in maple syrup. Morselli and Baggett (1984) developed an approved procedure for the detection of adulteration of maple syrup with 20% or more of corn or cane sugars/syrups using carbon isotope analysis. Stuckel and Low (1995) investigated maple syrup authenticity by high-performance anion exchange liquid chromatography with pulsed amperometric detec-tion (HPAE-PAD) based on oligosaccharide fingerprinting.…”