Abstract: Maillard reaction is considered to be an important way to form heterocyclic aromatic amines (HCAs). In this study, the model system of β-carboline HCAs was established with tryptophan, glucose and creatinine as reaction substrates to further understand the relationship between Maillard reaction and its associated hazardous substances. The reactions were carried out at 160, 180 and 200℃ for different times. Then β-carboline HCA concentration in Maillard reaction products (MRPs) was determined by ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS) and quantified with multiple reaction monitoring (MRM) mode after the pretreatment of final products. A precise pH meter was used to determine the terminal pH value of the reactions by immediately cooling the solutions of MRPs to room temperature. The absorbance of the MRP solutions were detected at 420 and 294 nm, which are the frequencies of browning intensity and of intermediates in the model reaction systems, respectively. The MRPs were diluted with methanol to obtain the absorbance data at 420 and 294 nm. Methanol was used as the reference. The DPPH·scavenging activity and ferric reducing antioxidant power (FRAP) assay were carried out to evaluate the antioxidant activity of the MRPs. In addition, the volatile components of model systems were determined by solid-phase micro-extraction (SPME) combined with gas chromatography-mass spectrometry (GC-MS).The results revealed that the β-carboline HCAs Norharman and Harman increased with the increase of reaction time and temperature. After reaction at 200℃ for 120 min, the total concentration of β-carboline HCAs reached 106.05 μg/mL, the concentration of Norharman and Harman was 85.99 and 20.06 μg/mL, respectively. The level of Norharman was much higher than that of Harman. In addition, pH, intermediates and browning intensity of the system all showed an upward trend with the increase of time and temperature. However, there was no regular pattern in the antioxidant activity including DPPH·scavenging activity and FRAP. And then the correlations between detection indices (including pH, intermediates, browning intensity and antioxidant activity) and β-carboline HCAs were analyzed. In the results, pH, intermediates and browning intensity displayed a significantly positive (P< 0.01) relationship with HCA (including Norharman and Harman) levels. Particularly, the correlation coefficients between β-carboline HCA levels and pH, intermediates and browning intensity were 0.857, 0.805 and 0.885, respectively. While the correlation between β-carboline HCAs and antioxidation was not found. The analysis results of volatile substances showed that the types of volatile substances and the content of most volatile substances increased with the increase of reaction time and temperature in the model systems. At most 17 compounds mainly containing pyrazines were identified among all the tested model systems. Additionally, the indole levels in the model systems also increased with the increase of reaction time and temperature. Indole is an imine with weak basicity, which is also the reason for the increase of pH value of the system.Maillard reaction mechanism is complex and the MRPs are made of various substances. Full usage of its reaction products in food industry, such as the application of its products with antioxidant activity, requires focusing on the harmful substances such as HCAs in the process. The current study provides research basis for regulating the quality of food Maillard system and the amounts of HCA generation.