Maple syrup adulteration

Honey and maple syrup are complex products of high market price (813C — 23%o). The main source of adulteration is cheap high fructose corn syrup (813C — 13%o) or cane sugar (813C —ll%o) and the adulterated product is easily detected at levels as low as 10% or so of added sugar. 

Due to dissolved minerals in maple syrup, the conductivity can range from about 90 to slightly above 230 (iS/cm, with a trend towards increasing conductivity as light transmittance of syrup decreases. Conductivity of syrup is sometimes used as a rapid screening test for adulteration of syrup, especially in Canada. 

Due to the wide differences in the price of maple and sugars from other origins, there is a considerable incentive for adulteration. The simplest is the addition of cane, com, or beet sugar to maple syrup. A great deal of research has been conducted on this problem. 

Paradkar, M. M., Sivakesava, S., and Irudayaraj, J. (2003). Discrimination and classification of adulterants in maple syrup with the use of infrared spectroscopic techniques. ]. Sci. Food Agric. 83, 714-721. 

The coupling of SNIF-NMR with stable isotope ratio analysis/mass spectrometry has been the basis of a method for detection of adulteration of maple syrup with beet, cane, or com sugar.192 Adulteration of mustard oil by the addition of synthetic allyl isothiocyanate, its major component, is of economic interest, and therefore a combined NMR and mass spectrometry method was developed, enabling the distinction between the natural and the synthetic compound, as well as the determination of the geographical origin of natural mustard oils.193 Similar methods have been used for the analysis of flavourings such as vanilla flavour (vanillin and p-hydroxybenzaldehyde),194195 benzaldehyde,196 and others.197... 

Food adulteration Quality assurance of food products is an important activity in the food industry where the substitution of lower cost alternatives constitutes fraud as well as a public health risk. Stable isotope measurements have been successfully applied to many instances where all-natural fruit juices, honey and maple syrup have been artificially sweetened. This is possible when the added sugar is from a plant species which follows a different photosynthetic pathway from that of the bulk material (C3 versus C4 plants), leading to a d C composition of the food product intermediate to the 124 difference between the two plant types. 

More recently, the carbon stable isotope ratio test (SIRA) has become an easy method to detect adulteration with cane and corn syrup (Carro et al, 1980). Because maple trees are C3 plants with a somewhat different photosynthetic pathway for carbon fixation, the ratio of 13C/12C in the sugar produced is different than cane or com. Maple has a 813C of approximately —24.5, whereas com and cane are closer to a 813C of —8 to —12. Thus, even a small addition of cane or corn syrup is readily detectable. Because beets are also C3 plants, the SIRA test is not able to detect adulteration with beet sugar. Improvement of the SIRA method is possible using malic acid as an internal standard (Tremblay and Paquin, 2007). 

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