The results demonstrated the penetration effect of microwave heating, and this occurred in a reaction solution of volume 60 mL from temperature–time profiles in the microwave system. The PSPY degradation produced two major intermediate products, 2acetylfuran and 5-methylfurfural, whose formation was detected from their fluorescence intensity. Maillard reaction intermediate products were observed, evidenced by A292 and fluorescence intensity. Further development of browning was noticeable at A420. Maximum emission of synchronous fluorescence spectra at 370–390 nm was not detected in previous works. All data failed to show any significant athermal effects of compositional changes in the Maillard reaction products.