Application of Raman spectroscopy in a correlation study between protein oxidation/denaturation and conformational changes in beef after repeated freeze–thaw.

Knowledge of protein properties is vital for quality assessment in meat systems. This study applied Raman spectroscopy to investigate the relationship between protein oxidation/denaturation and conformational changes in beef during repeated freeze–thaw (RFT). A lower α‐helix and higher β‐sheet content was observed after RFT. The I850 cm−1/I830 cm−1 intensity ratio of tyrosine indicates that tyrosine residues were exposed to the polar environment during RFT. Further, RFT led to increased carbonyl content and surface hydrophobicity, with decreased total sulphydryl content, Ca2+‐ATPase activity and enthalpy of myosin (ΔH1). Subsequently, correlation analysis showed that carbonyl content, Ca2+‐ATPase activity and ΔH1 in beef protein have good correlations with secondary protein structure data, especially ΔH1, which has a strong negative correlation (r = −0.906) with the β‐sheet/α‐helix ratio. Therefore, protein secondary conformation information during RFT has the potential to be used as a parameter for studying the thermal properties of myosin. [ABSTRACT FROM AUTHOR]