Application of ²H SNIF-NMR and ¹³C SIRA-MS Analyses to Maple Syrup:  Detection of Added Sugars

Abstract

The SNIF-NMR method may be used to measure the site specific isotope concentrations in a variety of organic compounds. The most common application of this technique involves quantitative deuterium nuclear magnetic resonance spectroscopy with appropriate interpretation of the accumulated spectra. SNIF-NMR together with SIRA-MS provides a powerful tool for food authentication and characterization. The concerted use of SNIF-NMR (deuterium) and SIRA-MS (carbon-13) on ethanol fermented from sugars has proven invaluable to the authentication of wines, spirits, and fruit juices. In this work, the analysis is extended to the authentication of maple syrup, a product rich in sucrose. Authentic maple syrup samples have been analyzed in detail to characterize the intrinsic variability of the isotopic ratios in this product. These data constitute a data base of authentic samples to which an unknown example of maple syrup can be compared. The isotopic ratios obtained from maple syrup are very different from those of both beet and cane or corn sugars. Therefore, the methodologies developed in this work are applicable for the detection of beet and cane or corn sugar added to a maple syrup. It can be shown that, through a simple statistical comparison between the data base and the unknown, a determination of the occurrence and/or extent of adulteration with added sugar can be made. Keywords: Maple syrup; adulteration; NMR; isotopic analysis; SNIF-NMR; sugar analysis

Food traceability using the 87Sr/86Sr isotopic ratio mass spectrometry

“…This affects the subsequent correction actions with use of the 88 Sr/ 86 Sr ratio reference value of 8.37861, which can no longer be considered as invariant. In order to perform internal mass bias correction of 87 Sr/ 86 Sr data, an alternative method with the implementation of a combination of standard-sample-standard bracketing and internal normalization was successfully proposed [34]; here the certified value of 8.37861 for the 88 Sr/ 86 Sr ratio in NIST 987 was used for mass bias correction of 90 Zr/ 91 Zr in two adjacent spiked solutions of NIST 987, which was then used to normalize Sr ratios in the samples. The additional advantage, with respect to the traditional direct standard-samplestandard bracketing, was that correction for short-term drift in mass bias was also achieved, through a continuous monitoring of Zr.…”

“…One of the first applications, concerning butter, used both light isotopes, already in use [90], and the 87 Sr/ 86 Sr isotope ratio [91]. This food comes from the lipid fraction of milk, whose trade is vast because of its easy transport; for this reason, this research had to find samples from many countries, planning isotopic ratio measurements for O, C, N, S as well as for Sr for all of them.…”

Light-Element Isotopes (H, C, N, and O) as Tracers of Human Diet: A Case Study on Fast Food Meals

“…For example, a two-source mixing model can be used to detect the introduction of a C 4 -plant derived adulterant (cane sugar; d 13 C ¼ À12.5‰) to C 3 -plant derived food item (maple syrup; d 13 C ¼ À23.6‰) (Martin et al 1996). This approach has also been used to detect the adulteration of wildflower honey, a C 3 plant-based food, with C 4 sugars (White et al 1998).…”

Determinação da origem biossintética de ácido acético através da técnica "Site Specific Natural Isotopic Fractionation Studied by Nuclear Magnetic Resonance (SNIF-NMR)"

“…O enriquecimento acontece quando há necessidade da adição de açúcar ao mosto da uva antes da fermentação com objetivo de aumentar o teor alcoólico e, conseqüentemen-te, a qualidade do vinho. Essa adição não se configura necessariamente em uma fraude, uma vez que é permitida dependendo das condições climáticas para uma determinada safra 2 . A técnica SNIF-NMR também tem sido utilizada para averiguar a adição de açúcares não declarados em outros produtos além do vinho 3,4 , como por ex., em sucos de frutas [5][6][7] , mel 8 , tequila 9 , entre outros [10][11][12][13][14] .…”

“…Muitos dos estudos já realizados, para vinagres e outros produtos, estão baseados na relação isotópica entre 13 C e 12 C obtida por meio da espectrometria de massas 17 . No entanto, essa técnica não é totalmente eficiente quando aplicada à detecção de adulterações que envolvam compostos oriundos de plantas que possuem o mesmo ciclo de fixação do carbono 2 , como por ex., de plantas C 3 . Por isso, tornou-se necessária a implementação de uma técnica para superar essa dificuldade e a SNIF-NMR veio suprimir essa lacuna.…”