Determination of α-dicarbonyl compounds and 5-hydroxymethylfurfural in commercially available preserved dried fruits and edible seeds by optimized UHPLC-HR/MS and GC-TQ/MS

Thermal processing, Maillard reaction, and caramelization favors the formation of alpha-dicarbonyl compounds during thermal dehydration of fruits and edible seeds roasting, which are extensively discussed as precursors of different undesirable compounds such as 5- hydroxymethylfurfural. Different studies have focussed on prevalence of alpha-dicarbonyl compounds and determination of 5-hydroxymethylfurfural from simple food matrices. However, still extensive studies are needed to be carried out for their determination from these complex food matrices for human awareness. In this study, the prevalence of alpha-dicarbonyl compounds and 5-hydroxymethylfurfural was investigated using an optimized UHPLC-HR/MS after ortho-phenylenediamine derivatization, and by an optimized GC-TQ/MS, respectively. Eight different categories of dried fruits and four categories of edible seeds were analyzed for prevalence of 3-deoxyglucosone (3-DG), glucosone (G), glyoxal (GO), methylglyoxal (MGO), and 5-hydroxymethylfurfural (5-HMF). Significantly higher prevalence of 3-DG was shown in raisins with concentration of 43.36 +/- 1.16 mg/kg; however, 5-HMF has shown significantly higher concentrations (165.90 +/- 4.41 mg/kg) in dried mango category. Moreover, edible seeds category has shown higher prevalence of 3-DG with 3.80 +/- 0.28 mg/kg in hazelnuts and 75.44 +/- 3.13 mg/kg of 5-HMF from peanuts. Interestingly, higher concentration of 5-HMF was determined in all analyzed samples than 3-DG, indicating a relation between the conversion of alpha-dicarbonyl compounds into 5-HMF during the dehydration process or roasting of dried fruits and edible seeds, respectively. Moreover, these methods were also validated in terms of recovery, specificity, accuracy, limit of detection, limit of quantification, and relative standard deviation for all analyzed compounds. Practical Application This study has conducted to get awareness about formation of harmful compounds during processing of fruits and edible seeds in order to get them preserved for long time and to increase their taste properties. This study has clearly stated the prevalence of alpha-dicarbonyl compounds and 5-hydroxymethylfurfural which can later convert into more toxic compounds upon changes in their conformation. Hence, the routine or excessive usage might be health hazardous for us. Moreover, companies should also apply more careful processing conditions posing less effect on fruit matrix.