Pulsed electric field (PEF)-induced aggregation between lysozyme, ovalbumin and ovotransferrin in multi-protein system

• Published in: Food chemistry 2015-05, Vol.175, p.115-120
• Main Authors: Wu, Li, Zhao, Wei, Yang, Ruijin, Yan, Wenxu
• Format: Article
• Language: English
• Subjects: Citric acid; Conalbumin - chemistry; Electricity; Food Handling - methods; Lysozyme; Muramidase - chemistry; Ovalbumin; Ovalbumin - chemistry; Ovotransferrin; Pasteurization; Pulsed electric fields
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2014.11.136

•Lysozyme was important to form insoluble aggregates during PEF treatment.•SDS–PAGE showed that aggregates partially resulted from non-covalent bonds.•Main components of aggregates were lysozyme, ovalbumin and ovotransferrin.•Lysozyme was relatively the higher component of aggregates.•During PEF processing, citric acid could inhibit aggregation but NEM could not. The aggregation of multi-proteins is of great interest in food processing and a good understanding of the formation of aggregates during PEF processing is needed for the application of the process to pasteurize protein-based foods. The aggregates formation of a multi-protein system (containing ovalbumin, ovotransferrin and lysozyme) was studied through turbidity, size exclusion chromatography and SDS–PAGE patterns for interaction studies and binding forces. Results from size exclusion chromatography indicated that there was no soluble aggregates formed during PEF processing. The existence of lysozyme was important to form insoluble aggregates in the chosen ovalbumin solution. The results of SDS–PAGE patterns indicated that lysozyme was prone to precipitate, and was relatively the higher component of aggregates. Citric acid could be effective in inhibiting lysozyme from interacting with other proteins during PEF processing. Blocking the free sulphydryl by N-ethylmaleimide (NEM) did not affect aggregation inhibition.