Abstract: This study selected 11 amino acids that may participate in the Maillard reaction during the processing of Pixian broad-bean paste (PXBP), resulting in the production of the characteristic aroma, to construct Maillard reaction systems consisting of single or combined amino acids and PXBP aqueous extract in order to explore the contribution of exogenous amino acids to the characteristic flavor of PXBP. The results of solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) showed that 17 key aroma compounds were obtained from the Maillard reaction products (MRPs) derived from 11 single amino acids. According to the contribution of the amino acids to the key aroma compounds of PXBP, phenylalanine (Phe), methionine (Met), arginine (Arg), aspartic acid (Asp), lysine (Lys) and leucine (Leu) were selected to construct Maillard reaction systems containing mixed amino acids. Based on sensory evaluation and the number and amount of key compounds, the optimum reaction system consisted of 1.400 g of Asp, 0.720 g of Arg, 0.100 g of Met, 0.740 g of Leu, 0.480 g of Phe and 0.500 g of Lys in every 50 mL of PXBP aqueous extract. The combined addition of amino acids improved the types and contents of key aroma compounds in PXBP, imparting a better-balanced and stronger flavor to the product.

Key words: Pixian broad-bean paste; amino acids; Maillard reaction; key aroma compounds; sensory analysis