Analysis of Reducing Carbohydrates and Fructosyl Saccharides in Maple Syrup and Maple Sugar by CE

Reducing carbohydrates in maple syrup and maple sugar were separated by capillary electrophoresis using derivatization with 1-phenyl-3-methyl-5-pyrazolone (PMP) and the characteristics of these samples were studied. Reducing carbohydrate standards including nine monosaccharides and five disaccharides as PMP derivatives could be easily resolved by using 200 mM borate buffer (pH 10.5) as a background electrolyte. Glucose was the most abundant reducing sugar in both maple samples, and mannose was abundant relative to the other sugars. The other monosaccharides (xylose, arabinose, ribose, galactose and N-acetylglucosamine) were also detected. When maple syrup and maple sugar were treated with invertase, which removed fructose residues from the reducing ends of fructosyl saccharides, melibiose was detected, suggesting that raffinose exists in both samples. The differences of carbohydrate contents between maple syrup and maple sugar were also discussed.