Reduced functionality of PSE-like chicken breast meat batter resulting from alterations in protein conformation. (9th January 2015)

• Record Type: Journal Article
• Authors: Li, K.; Zhao, Y. Y.; Kang, Z. L.; Wang, P.; Han, M. Y.; Xu, X. L.; Zhou, G. H.
• Is Part Of: Poultry science. Volume 94:Number 1(2015:Jan.)
• Page Start: 111
• Page End: 122
• Publication Date: 2015-01-09
• Subjects: PSE-like -- chicken -- protein conformation -- LF-NMR -- Raman spectroscopy; Poultry -- Periodicals; Poultry -- Periodicals; Poultry Diseases -- Periodicals; Electronic journals; 636.5005
• DOI: 10.3382/ps/peu040
• Languages: English
• ISSNs: 0032-5791

Abstract

Abstract : The objectives of this study were to evaluate protein thermal stability, water-protein interaction, microstructure, and protein conformation between PSE-like and normal chicken breast meat batters. Sixty pale, soft, and exudative (PSE)-like (L*>53, pH24 h <5.7) and 60 normal (46<L*<53, 5.724 h <6.1) chicken breast meats were selected from 3 different occasions in a major Chinese commercial plant. Two different meat batters were formulated to 14% meat protein and 2% salt, and they were analyzed for the protein changes and the microstructure using differential scanning calorimetry, low-field (LF)-NMR, SEM, and Raman spectroscopy. PSE-like meat batter had lower gel strength, water-holding capacity, and salt-soluble protein extraction ( P < 0.05). Heated PSE-like meat batter formed an aggregated gel matrix, while normal meat batter produced a compact gel network with fine, cross-linked strands by many protein filaments. LF-NMR revealed an increase in the water mobility in heated PSE-like meat batter with an increasing amount of loosely bound water ( P < 0.05). No significant changes were observed in the electrophoretic patterns of salt-soluble protein extracts by SDS-PAGE. However, differential scanning calorimetry showed that PSE-like meat had greater myosin and sarcoplasmic proteins/collagen denaturation ( P < 0.05). In PSE-like meat, actin denaturation was particular evident after salt addition ( P < 0.05) using differential scanning calorimetry. Moreover, Raman spectroscopy indicated that PSE-like meat batter had less unfolded α-helix and β-sheet structure formation, reduced exposure of hydrophobic and tyrosine residues ( P < 0.05), and changes in the microenvironment of aliphatic residues and tryptophan, which affected salt-soluble protein extraction, gel properties, and water-holding capacity. In conclusion, the inferior functional properties of PSE-like meat were attributed to not only myosin denaturation, but also actin denaturation after salt addition and different protein structural states.