LC-MS/MS for simultaneous detection and quantification of Amadori compounds in tomato products and dry foods and factors affecting the formation and antioxidant activities

In order to establish an efficient detection method to evaluate the formation of Amadori compounds (ACs) in food products and study the potential health effects, an ultra-high performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method using caffeine as internal standard was developed to determine eight ACs. The detection limits ranged from 0.0179 to 0.0887 mg/L for the ACs. The accuracy of the method was tested through measuring recovery of the spiked samples that varied from 81.90 +/- 2.98% to 108.74 +/- 2.34%. This method was further applied to detect ACs in 10 food products. Results showed that dry fruits and vegetables were rich in ACs, the total content of ACs varied from 1.36 +/- 0.26 to 3415.91 +/- 147.96 mg/100 g. The total amount of ACs in tomato juice heated under vacuum condition showed significant increment (P < 0.05) in 25 min at 80 degrees C comparing with that under atmospheric pressure due to the rapid loss of water. Besides, the amino acid content shows positive correlation with the corresponding AC formation in Maillard reaction during food drying. After heated at fixed water activity (Aw) for 4 hr by sous-vide process, the ACs content in tomato powder increased significantly and the antioxidant activity improved as well. Practical Application Results of this study provided a valuable tool to evaluate the formation of ACs in complex dry food products, facilitated the quality control of food products. The knowledge obtained will offer useful information to food processors. The synthesized ACs would facilitate further study into the antioxidant activities and potential health effects of specified AC.