## 3 Results and Discussion  
### Characterization of Maple Syrup Samples  
Reference analysis results for total soluble solids (\({}^{\circ}\)Brix), sugar (sucrose, fructose, and glucose), and total phenolics for all samples, including traditional maple syrup, bourbon barrel (BBL)-aged maple syrup, and table syrups (corn, cane, and mixture--consisted of cane, maple, and agave syrups) are summarized in Table 1.  
Traditional map syrups and BBL maple syrups showed similar total soluble solids (\({}^{\circ}\)Brix) contents (Table 1). The \({}^{\circ}\)Brix values of maple syrups (65.4-68.7\({}^{\circ}\) with an average of 66.6 \(\pm\) 0.7\({}^{\circ}\)) were within the range reported by [PERSON] and [PERSON] (62.2-74.0\({}^{\circ}\) with an average of 67.0 \(\pm\) 1.6\({}^{\circ}\)) [4] and [PERSON] (66-68\({}^{\circ}\)) [26]. Sucrose, fructose, and glucose contents of traditional and BBL maple syrups are summarized in Table 1. We found no significant difference (\(p\) = 0.98, \(p\) > 0.05) in the sugar content between traditional and BBL maple syrups. Most sucrose contents of maple syrups agree with the reported literature (51.7-75.6% with an average of 68.0 \(\pm\) 4.0%) [4], while four labeled as traditional maple syrup samples were far below the range (22.0, 23.5, 36.1, and 50.6%). These same four samples have much higher fructose (9.5-17.1%) and glucose (9.7-17.1%) contents than the literature reports (fructose 0.3 \(\pm\) 0.5%, and glucose 0.4 \(\pm\) 1.1%) [4]. In [PERSON]'s study, fructose content in maple syrup was undetectable, and glucose content ranged from 0-7.3% [27]. The glucose to fructose ratio of 3 of the suspect samples was -1:1, while the other had a 1:1.6 ratio. Invert sugar in maple syrups can be produced from sucrose hydrolysis during thermal processing or microbial contamination of the sap [26]. However, the abnormally high invert sugar contents and low sucrose contents in the samples indicate the potential adulteration of maple syrup with inexpensive table syrups. We evaluated commercial table syrup blends that showed similar levels of fructose (13.3 \(\pm\) 0.8%), glucose (12.3 \(\pm\) 1.9%), and sucrose 21.7 \(\pm\) 7.8%) content to the suspect maple syrups. Figure 1 shows the representative HPLC chromatograms of traditional maple syrup, suspicious maple syrup (which has high invert sugar and low sucrose content), BBL maple syrups are shown in Figure 2. The corresponding \(p\)-Value values of the \(p\)-Value values are 0.001 \(\pm\) 0.  
sympt and table syrup (specifically corn syrup). The sugar profiles of both traditional and BBL maple syrups obtained by HPLC showed sucrose as the dominant sugar, while the suspicious maple syrup had noticeably high fructose and glucose contents as well as a detectable but low maltose content. In the literature, it has been stated that authentic maple syrup should not have any detectable maltose content [1]. Furthermore, it has been reported that syrup sweeteners, including molasses, high fructose corn syrup, and honey, have wide maltose composition variability, from 3.0-14.4% [28]. The total phenolic contents of traditional maple syrups and BBL maple syrups are summarized in Table 1. In previous reports, total phenolic contents in maple syrups ranged from 200-900 ug/mL, which agreed with our findings [29; 30]. Since the FC method is based on the reagent's chemical reduction, the most problematic assay interference could be the presence of reducing sugars and samples with high protein levels [19]. In traditional maple syrups (except for suspicious ones) and BBL maple syrups, reducing sugars were undetectable. In addition, according to the literature, protein contents in maple syrups are in low concentration (-0-50 ppm) [1]. Therefore, the FC method can be considered a suitable method for analyzing total phenolics in maple syrups. The suspicious maple syrups were excluded from this analysis due to a high-level of reducing sugar (glucose and fructose) content.