Modification of the physicochemical and structural characteristics of zein suspension by dielectric barrier discharge cold plasma treatment

• Published in: Journal of food science Vol. 85; no. 8; pp. 2452 - 2460
• Main Authors: Li, Nan, Yu, Jiao‐jiao, Jin, Nan, Chen, Yue, Li, Shu‐hong, Chen, Ye
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.08.2020
• Subjects: Chemical Phenomena; Chemical precipitation; Cold plasmas; Cold treatment; Covalent bonds; Dielectric barrier discharge; dielectric barrier discharge (DBD); Dielectric properties; Dielectric strength; dispersion stability; Electricity; Food industry; Food processing industry; Food Technology - methods; Hydrogen Bonding; Hydrogen bonds; Hydrophilicity; Hydrophobic and Hydrophilic Interactions; Hydrophobicity; Micelles; Nanoparticles - chemistry; Particle Size; Peptides; Protein Conformation; Protein structure; Proteins; Secondary structure; Solubility; Sulfhydryl Compounds - analysis; Suspensions - chemistry; Water - chemistry; Zein; Zein - chemistry; zein; solubility; dispersion stability; dielectric barrier discharge (DBD); hydrophilicity
• ISSN: 0022-1147; 1750-3841
• DOI: 10.1111/1750-3841.15350

Owing to the strong hydrophobicity of zein, improved solubility is required to enhance the recovery of bioactive peptides. Using a zein suspension prepared by the antisolvent precipitation method, the impact of varying the voltage during dielectric barrier discharge (DBD) treatment on the physicochemical and conformational properties of zein in water was investigated. Analysis of the particle size, specific surface area, and free sulfhydryl content indicated that the protein solubility was maximized by treatment at 70 V for 70 s. DBD treatment destroyed covalent bonds and introduced some hydrophilic groups onto the zein surface, thus enhancing the contact area with water molecules and leading to a more uniform dispersion. A decrease in the hydrodynamic radius of zein micelles indicated that intermolecular interactions were disrupted, thus improving dispersion stability. A more hydrophilic microenvironment was formed owing to the reduction in hydrophobic interactions. Additionally, evaluation of the secondary structure demonstrated that DBD treatment broke hydrogen bonds, resulting in a loose conformation with more exposed sites of action for water. These results are expected to facilitate the development of technologies for improving utilization of zein. Practical Application Strong hydrophobicity limits the application of zein in the food industry. The study indicated that DBD treatment could promote loose structure, and improve dispersion stability and hydrophilicity of zein suspension prepared by antisolvent precipitation method. This work revealed the potential of cold plasma treatment for modifying zein and other insoluble proteins, which would expand their scope of application.