Degradation of Di (2-ethylhexyl) Phthalic Acid Plasticizer in Baijiu by a Foam Titanium Flow Reactor Attached with Hairpin-like Structured Peptide Enzyme Mimics

Because of the significant environmental and health hazards imposed by di(2-ethylhexyl) phthalate (DEHP), a common plasticizer, developing safe and green techniques to degrade DEHP plasticizer is of huge scientific significance. It has been observed that environmental contamination of DEHP may also induce serious food safety problems because crops raised in plasticizers contaminated soils would transfer the plasticizer into foods, such as Baijiu. Additionally, when plastic packaging or vessels are used during Baijiu fermentation and processing, plasticizer compounds frequently migrate and contaminate the product. In this study, hairpin-like structured peptides with catalytically active sites containing serine, histidine and aspartic acid were found to degrade DEHP. Furthermore, after incorporating caffeic acid molecules at the N-terminus, the peptides could be attached onto foam titanium (Ti) surfaces via enediol-metal interactions to create an enzyme-mimicking flow reactor for the degradation of DEHP in Baijiu. The structure and catalytic activity of peptides, their interaction with DEHP substrate and the hydrolysis mechanism of DEHP were discussed in this work. The stability and reusability of the peptide-modified foam Ti flow reactor were also investigated. This approach provides an effective technique for the degradation of plasticizer compounds.