Alcalase and neutral protease are widely employed for producing soybean antioxidant peptides, but their synergy mechanisms remain unclear. In this work, soybean protein isolate (SPI) was hydrolyzed synergistically by the two proteases. The products by Alcalase exhibited a larger proportion of low molecular-weight (MW, <1 kDa) peptides compared to those from neutral protease (87.74 % vs 76.08 %). After synergistic hydrolysis, an “averaging” effect on free amino acid composition and MW distribution was observed, but the peptide length distribution shifted evidently towards dipeptides (57.07 % with simultaneous enzyme use, compared to 20.43 % and 33.70 % for individual enzymes). Similarly, the N/C-terminal residue distribution also displayed an ‘averaging’ trend. Furthermore, synergistic processing increased the proportion (approximately 7 %) of potential antioxidant peptides with predicted probability >0.7, aligning with observed non-additive antioxidant activities and suggesting a synergistic mechanism beyond simple additivity. We hope the work could provide guidance and references for the target peptide release from SPI.
In this study, protein isolate (PI) and protein-phenolic complex (PPC) were prepared from Cinnamomum camphora seed kernel (CCSK). The effects of naturally present phenolic compounds on the structural characteristics, functional properties and antioxidant activities of CCSK protein before and after hydrolysis by Alcalase were evaluated. The formation of PPC was confirmed by the ultraviolet–visible and intrinsic fluorescence spectra. The resultant PPC hydrolysates (PPHs) had higher degree of hydrolysis values than PI hydrolysates (PHs). Fourier transform infrared spectroscopy analysis showed that PHs and PPHs had more disordered structure, with the increase of random coil content. PI and PPC had similar solubility curves in the pH range of 2.0–9.0. However, hydrolysis led to a decrease in the solubility of PHs and PPHs at pH 2.0 and 3.0, and the solubility of PPHs was higher than that of PHs at pH 6.0 and 7.0. In addition, PPC exhibited better emulsifying properties and stronger antioxidant activities than those of PI before and after hydrolysis. These results indicated that PPC and PPHs obtained from CCSK may have great application potential in food industry as functional ingredients.
This study used alcalase derived from Bacillus licheniformis as the research object. We revealed the mechanism by which pulsed electric field (PEF) treatment increases alcalase activity. Alcalase is widely used in the food and brewing industries. The results showed that alcalase activity was increased by 11.26%, α-helix structure was reduced by 18.80%, and the number of hydrogen bonds in the molecule also was decreased from 309 to 305 at 10 kV/cm, which showed that the partial unfolding of the secondary structure was an important factor leading to an increase in alcalase activity. In contrast, fluorescence intensity and ζ-potential were reduced by 61.28% and 17.99%, respectively, and the binding energy between alcalase and casein in molecular docking increased by 15.07%, indicating that the tertiary structure was also a key factor in improving activity. Furthermore, molecular docking technology intuitively reflects that PEF treatment increased alcalase activity.
危险品化学品经营许可证（带存储）