Development and UFLC-MS/MS Characterization of a Product-Specific Standard for Phenolic Quantification of Maple-Derived Foods

Abstract

The phenolic contents of plant foods are commonly quantified by the Folin-Ciocalteu assay based on gallic acid equivalents (GAEs). However, this may lead to inaccuracies since gallic acid is not always representative of the structural heterogeneity of plant phenolics. Therefore, product-specific standards have been developed for the phenolic quantification of several foods. Currently, maple-derived foods (syrup, sugar, sap/water, and extracts) are quantified for phenolic contents based on GAEs. Since lignans are the predominant phenolics present in maple, herein, a maple phenolic lignan-enriched standard (MaPLES) was purified (by chromatography) and characterized (by UFLC-MS/MS with lignans previously isolated from maple syrup). Using MaPLES and secoisolariciresinol (a commercially available lignan), the phenolic contents of the maple-derived foods increased threefold compared to GAEs. Therefore, lignan-based standards are more appropriate for phenolic quantification of maple-derived foods vs. GAEs. Also, MaPLES can be utilized for the authentication and detection of fake label claims on maple products.

Anti-glycation and anti-oxidative effects of a phenolic-enriched maple syrup extract and its protective effects on normal human colon cells

“…28 With regards to the phenolic content of the extract, we have previously reported on the development of a maple product specific standard, named MaPLES (maple phenolic lignan-enriched standard), for the quantification of phenolic content of maple-derived food products since MSX contains predominantly lignans which cannot be adequately quantified based on gallic acid equivalents (GAEs). 35 Therefore, MSX contains 92.4% phenolic content based on MaPLES equivalents; see Supplementary Information Table S1). Notably, MSX contains a similar chemical compositional profile of bioactive substances as the whole food natural sweetener, maple syrup, but with reduced sucrose content (<0.1%).…”

Isolation, Identification, and Biological Evaluation of Phenolic Compounds from a Traditional North American Confectionery, Maple Sugar

“…Maple sugar (25 kg) was produced by the Federation of Maple Syrup Producers of Quebec (Longueil, Quebec, Canada) as previously reported by our laboratory. 10 Briefly, maple syrup (containing <1% inverted sugar to ensure crystallization) was slowly heated in baking pans (to 22−24 °C higher than the boiling point of 100 °C), which were then cooled on a cold surface (ca. 1 min/L) followed by immersion in cold water (4 °C for 2−5 min) to promote the formation of sugar crystals.…”

Phenolic‐enriched maple syrup extract protects human keratinocytes against hydrogen peroxide and methylglyoxal induced cytotoxicity

“…A standardized food grade phenolic‐enriched maple syrup extract (MSX), which contains over 90% of phenolic compounds (determined by High‐performance liquid chromatography, liquid chromatography‐mass spectrometry, and nuclear magnetic resonance methods), was prepared in our laboratory as previously reported 23‐26 . Our previous phytochemical characterization studies of MSX led to the isolation and identification of several phenolic subclasses including lignans, gallic acid derivatives and other phenolic acids, coumarins, and stilbenes 23 .…”