关键词: 射流空化, 大豆11S球蛋白, 结构, 功能特性

Abstract: The effect of different durations of jet cavitation treatment on the structural (fluorescence spectrum, Fourier transform infrared spectrum, surface hydrophobicity, and the contents of carbonyl groups, sulfhydryl groups and disulfide bonds) and functional properties (solubility, emulsifying properties, and foaming properties) of soybean 11S globulin at different concentrations was investigated. The results indicated that with the prolongation of jet cavitation treatment time, the maximum absorption wavelength (λmax) of 11S globulin at concentrations of 2 and 5 g/100 mL showed a red shift first and then a blue shift (the higher the concentration, the higher the λmax), and the fluorescence intensity increased first and then decreased. The α-helix and β-sheet structure of 11S globulin at 2 g/100 mL were converted into β-turn. Toward the end of the treatment, β-turn was converted into α-helix, and the content of random coils did not change significantly during the entire treatment period; at 5 g/100 mL, the α-helix, β-sheet and β-turn were transformed into a random coil structure, and toward the end, the secondary structure was transformed from random coil and β-turn to α-helix and β-sheet. At both concentrations, the surface hydrophobicity and the contents of carbonyl groups and free sulfhydryl groups increased first and then decreased with increasing treatment time, while the opposite trend was found for the content of disulfide bonds. The solubility, emulsifying properties and foaming properties were significantly improved by jet cavitation, and this effect was more obvious at 5 g/100 mL than at 2 g/100 mL. These results showed that jet cavitation can change the structure of soybean 11S globulin, and consequently improve its solubility, foaming properties and emulsifying properties, resulting in more obvious unfolding and aggregation of soybean 11S globulin at 5 g/100 mL as well as more improved functional properties.

Key words: jet cavitation, soybean 11S globulin, structure, functional properties