摘要

The effects of beer brewing process, especially mashing process on protein content, free thiol groups content and antioxidant activity of wort were examined. The results showed that the degradation of macromolecular proteins was accompanied by the formation of protein with low molecular weight during mashing. Protein and free thiol groups contents showed a pattern of increasing first and then decreasing, and both of them decreased from 310.63 μg/mL to 229.18 μg/mL, and from 0.61 μmol/g to 0.04 μmol/g, with the reduction of 26.22% and 93.44%, respectively after mashing, which indicated that mashing was an important stage in the key changes of protein and thiol groups. There were significant (p<0.01) positive correlations among protein content, free thiol groups content and ABTS free radical scavenging activity. Extension of the mashing time and increase of mashing temperature were beneficial to the dissolution and accumulation of protein in wort, which significantly improved the ABTS free radical scavenging activity, and increased the color and TBA of wort. Therefore, the protein in wort, especially lipid transfer protein 1 (LTP1) with antioxidant activity, had a positive effect on the oxidative stability of wort.

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