title: Emulsifying Properties of Oxidatively Stressed Myofibrillar Protein Emulsion Gels Prepared with (-)-Epigallocatechin-3-gallate and NaCl.
abstract: The dose-dependent effects of (-)-epigallocatechin-3-gallate (EGCG; 0, 100, or 1000 ppm) on the textural properties and stability of a myofibrillar protein (MP) emulsion gel were investigated. Addition of EGCG significantly inhibited formation of carbonyl but promoted the loss of both thiol and free amine groups. Addition of EGCG, particularly at 1000 ppm, initiated irreversible protein modifications, as evidenced by surface hydrophobicity changes, patterns in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and differential scanning calorimetry. These results indicated that MP was modified by additive reactions between the quinone of EGCG and thiols and free amines of proteins. These adducts increased cooking loss and destabilized the texture, especially with a large EGCG dose. Confocal laser scanning microscopy and scanning electron microscopy images clearly indicated the damage to the emulsifying properties and the collapse of the internal structure when the MP emulsion gel was treated with a large EGCG dose. A high concentration of NaCl (0.6 M) improved modification of MP and increased the rate of deterioration of the internal structure, especially with the large EGCG dose (1000 ppm), resulting in an MP emulsion gel with extremely unstable emulsifying properties.
authors.affiliation: College of Food Science and Engineering, Northwest A&F University , No. 22 Xinong Road, Yangling, Shaanxi 712100, China.
authors.forename: Xianchao
authors.identifier: http://orcid.org/0000-0002-8602-207X
authors.initials: X
authors.lastname: Feng
authors.affiliation: College of Food Science and Engineering, Northwest A&F University , No. 22 Xinong Road, Yangling, Shaanxi 712100, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Chen
authors.affiliation: College of Food Science and Engineering, Northwest A&F University , No. 22 Xinong Road, Yangling, Shaanxi 712100, China.
authors.forename: Na
authors.initials: N
authors.lastname: Lei
authors.affiliation: College of Food Science and Engineering, Northwest A&F University , No. 22 Xinong Road, Yangling, Shaanxi 712100, China.
authors.forename: Shuangxi
authors.initials: S
authors.lastname: Wang
authors.affiliation: Lab of Meat Processing and Quality Control of EDU, College of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Nanjing Agricultural University , Nanjing, Jiangsu 210095, China.
authors.forename: Xinglian
authors.initials: X
authors.lastname: Xu
authors.affiliation: Lab of Meat Processing and Quality Control of EDU, College of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Nanjing Agricultural University , Nanjing, Jiangsu 210095, China.
authors.forename: Guanghong
authors.initials: G
authors.lastname: Zhou
authors.affiliation: College of Food Science and Engineering, Northwest A&F University , No. 22 Xinong Road, Yangling, Shaanxi 712100, China.
authors.forename: Zhixi
authors.initials: Z
authors.lastname: Li
mesh_terms: D000818:Animals; D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry; D004655:Emulsions / Q000737:chemistry; D005782:Gels / Q000737:chemistry; D009124:Muscle Proteins / Q000737:chemistry*; D010084:Oxidation-Reduction; D012965:Sodium Chloride / Q000737:chemistry*; D013552:Swine
chemical_list: D004655:Emulsions; D005782:Gels; D009124:Muscle Proteins; D012965:Sodium Chloride; D002392:Catechin; C045651:epigallocatechin gallate
keywords: EGCG; chemical properties; confocal laser scanning microscopy; emulsion gel; microstructural properties; myofibrillar protein