Abstract: To clarify the effect of heat treatment on the binding of pea protein isolate (PPI) to typical beef aroma substances, gas chromatography-mass spectrometry (GC-MS), fluorescence spectrometry and other methods were used to explore the correlation between the binding rate and aroma properties and protein properties, as well as the interaction mechanism. The results showed that the binding rates of 2-methyl-3-mercaptofuran and (E,E)-2,4-decadienal, with larger hydrophobic coefficients (log P), to PPI were greater than 98% before and after heating. At room temperature, the binding rates of 5-(2-hydroxyethyl)-4-methylthiazole and 2-methylpyrazine to PPI were (80.34 ± 7.68)% and (17.58 ± 0.58)%, respectively and lower than those of 2-methyl-3-mercaptofuran and (E,E)-2,4-decadienal. With increasing heating temperature, the binding rate of 5-(2-hydroxyethyl)-4-methylthiazole decreased while that of 2-methylpyrazine increased. After heating at 100 ℃ for 10 min, the binding rates were (54.41 ± 4.14)% and (25.35 ± 1.26)%, respectively. After heating at 120 ℃ for 10 min and with increasing heating time at 100 ℃, the binding rate of 5-(2-hydroxyethyl)-4-methylthiazole and 2-methylpyrazine increased. Heat treatment increased the exposure of 2-methylpyrazine binding sites on the protein surface, and the protein and 2-methylpyrazine interacted via van der Waals forces and hydrogen bonds. These results provide a theoretical basis for flavor quality control of plant-based meat prepared from pea protein isolate during hot processing.

Key words: pea protein isolate; heat treatment; beef aroma substances; protein properties; interaction