Maple syrup standards

FIGURE 4.7 Maple syrup produced in paired evaporators boiling sap from the same source on the same dates. The evaporator that produced the syrup on the top was the standard, control evaporator. The syrup on the bottom was produced in an identical evaporator equipped with air injection. 

FIGURE 4.9 Transmission profiles of maple syrup. Profile for each grade was derived from 10-40 scans of individual syrups. Grades delineations are based upon U.S.D.A. standards. Color grade is determined by the transmittance of light at 560 nm. 

LMEA (Les Manufacturers d Equipements Acericoles) (2001). "Standards on Maple Equipment Intended for the Production of Maple Syrup." Saint-Adrien, Quebec. 

Tremblay, P. and Paquin, R. (2007). Improved detection of sugar addition to maple syrup using malic acid as internal standard and in 13C isotope ratio mass spectrometry (IRMS).. Agric. Food Chem. 55,197-203. 

Figure 6-7 CIE Chromaticity Diagram with Color Points for Maple Syrup and Honey Glass Color Standards...

An example of the application of the CIE system for color description is shown in Figure 6-7. The curved, dotted line originating from C represents the locus of the chromaticity coordinates of caramel and glycerol solutions. The chromaticity coordinates of maple syrup and honey follow the same locus. Three triangles on this curve represent the chromaticity coordinates of U.S. Department of Agriculture (USDA) glass color standards for... 

The procedure has been applied to the analysis of control urine and that from a patient with maple-syrup-urine disease. The results from 5 separate analyses in each case gave standard deviations of less than 10% of the mean. This was routinely achieved where the level of an amino acid was about 1 ng. 

Fig. 3.22. GC separation of keto and hydroxy acids from the urine of a patient with maple syrup urine disease. Top chromatogram, the patient before dietary treatment middle chromatogram, the same patient after two days on a diet bottom chromatogram, a mixture of reference compounds. Peaks 1, lactic acid 2, 2-hydroxyisobutyric acid 3, 2-hydroxybutyric acid 4, pyruvic acid 5, 3-hydroxyisobutyric acid 6, 3-hydroxybutyric acid 7, 2-hydroxyisovaleric acid 8, 2-ketobutyric acid 9, malonic acid (internal standard) 10, 2-methyl-3-hydroxybutyric acid 11, 2-hydroxy-n-valeric acid 12. methylmalonic acid 13, 3-hydroxyisovaleric acid 14a and b, 2-ketoisovaleric acid IS, acetoacetic add 16, 2-hydroxyisocaproic acid 17, 2-hydroxy-3-methylvaleric acid 18a, L-2-keto-3-methylvaleric add 18b, D-2-keto-3-methyl-valeric acid 19, 2-ketoisocaproic acid. Reproduced from [386],...

Jones describes standard maple syrup as follows Standard... 

Figure 10. HPLC of amino and imino adds after post-column deiivatization with NBD-F (Ref. 162). Abbreviations a = Asp b=Thr C = Ser d = Glu e=Pro f = Gly g = Ala h = Cys i = Val j = Met k = Ile 1 = Leu m = Nle (internal standard) n = Tyr o = Phe p = Lys q = His r = Arg s = Om t = allo-l e. Profile A is of a standard mixture. Profile B is of amino adds eluted from a filter-paper blood spot of a patient with phenylketonuria, showing a normal profile but with an abnormally large phenylalanine peak. Profiles C and D are from patinets with branched chain ketoaciduria (maple syrup urine disease) and tyrosinaemia respectively. Reprinted with permission from Y. Watanabe and K. Imai, Anal. Chem., 55, 1786 (1983). Copyright (1983) American Chemical Sodety.

Bruce and Turner (1952) developed polished glass standards, now in use, for determining color specifications and tolerances for maple syrup and honey, based on the C.I.E. system. They can be used for both clear and cloudy liquids. 

Fig. 10.1 Metabolites in the urine of an untreated patient with branched-chain keto aciduria (maple syrup urine disease). Extracted using ethyl acetate and separated as their trimethylsilyl-oxime derivatives on a 25 m SE-30 capillary column, using temperature programming from 80°C to 110°C at 0.5°C min and an injection split ratio 1 12 at a temperature of 250°C. The peaks marked R are due to solvent and reagents. Peak identifications are 1, lactic 2, 2-hydroxyisobutyric 3, 2-hydroxybutyric 4, pyruvic 5, 3-hydroxybutyric 6, 2-hydroxyisovaleric 7, 2-oxobutyric 8, 2-methyl-3-hydroxy-isovaleric 10, a and b, 2-oxoisovaleric 11, acetoacetic 12, 2-hydroxyisocaproic 13, 2-hydroxy-3-methyl- -valeric 14, 2-oxo-3-methyl-/i-valeric (14a L- 14b D-) 15, 2-oxoisocaproic acids. The internal standard was malonic acid. (Redrawn with modifications from Jellum etal., 1976)...

Fig. 10.3 Chromatogram of organic acids extracted from the urine of an untreated patient with branched-chain keto aciduria (maple syrup urine disease), extracted and separated as described in the legend to Fig. 10.2. The chromatogram illustrates the overlapping peaks in the regions occupied by 3-hydroxybutyric, 2-hydroxyisovaleric and 2-oxoisovaleric acids (peak 1) and 2-oxo-3-methyl-valeric, 2-hydroxyisocaprioic and 2-oxoisocaproic acids (peak 2) and phosphate (peak 3). Other peaks of interest are (4) citric, (5) 4-hydroxyphenyl-lactic, (6) 4-hydroxyphenylpyruvic, (7) n-tetracosane (standard) and (8) -hexacosane (standard). (Compare with Fig. 10.4.)...

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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