Raman spectroscopic study of effect of the cooking temperature and time on meat proteins

Changes in protein secondary structure during thermal treatment of whole meat were studied using Raman spectroscopy. Pork longissimus thoracis was heat treated at 50 to 70 °C for 2-10 h and 110 average Raman spectra were collected from all the combinations. The effect of cooking temperature on meat protein structure was highly pronounced compared to cooking time. Detailed information about the changes in protein structure affected by cooking temperature and time was revealed and Raman spectra from different cooking temperatures were readily discriminated by principal component analysis. Temperature had a significant effect on the intensity ratio of tyrosine (Tyr) and tryptophan (Trp) and on cooking loss. Good correlations were found between the Raman spectra and cooking temperature (R2 = 0.96), cooking loss (R2 = 0.82) and cooking time (R2 = 0.78). Raman spectroscopy proved to be a useful technique to follow the effect of cooking temperature and time on meat proteins in intact muscle.