Title
Whey protein isolate with improved film properties through cross-linking catalyzed by small laccase from Streptomyces coelicolor
Author
Wei Quan, Chong Zhang, Meixia Zheng, Zhaoxin Lu, Fengxia Lu
Year
2018
Journal
Journal of the Science of Food and Agriculture
Abstract
The effects of Small laccase (SLAC) from Streptomyces coelicolor on the prosperities of whey protein isolate (WPI) film were studied. WPI was catalyze by SLAC without phenolic acid assistance. Particle size distribution results showed that some complexes with higher relative molecular weight formed in WPI samples treated by SLAC. The content of α-helixes decreased, while those of β-sheets and random coils increased following SLAC treatment according to circular dichroism results. Fourier transform infrared spectral analysis suggested that some conformational changes occurred in WPI following SLAC treatment. Analysis of WPI films prepared by casting after SLAC treatment indicated that their film properties were all improved, including mechanical properties; solubility; water vapor, oxygen, and carbon dioxide barrier properties; film color; light transmission; transparency; and thermal properties. Compared with that of the control film, some obvious differences in the morphology of the WPI films were observed following SLAC treatment. This report demonstrates that laccase can directly catalyze protein cross-linking, which may be useful to improve the performance of protein films. In this study, SLAC was applied in WPI edible film during the film-making process. The results showed that SLAC can catalyze WPI cross-linking without phenolic acid assistance, and WPI film properties were improved after SLAC treatment.
Instrument
J-810
Keywords
Circular dichroism, Secondary structure, Biochemistry