Raman spectroscopy compared against traditional predictors of shear force in lamb m. longissimus lumborum

• First study to compare predictions of shear force at 1d and 5d using Raman spectra.
• First study comparing Raman spectra to myofibrillar breaks determined by microscopy.
• Predictability of fresh intact lamb loin shear force was low.

A Raman spectroscopic hand held device was used to predict shear force (SF) of 80 fresh lamb m. longissimus lumborum (LL) at 1 and 5 days post mortem (PM). Traditional predictors of SF including sarcomere length (SL), particle size (PS), cooking loss (CL), percentage myofibrillar breaks and pH were also measured. SF values were regressed against Raman spectra using partial least squares regression and against the traditional predictors using linear regression. The best prediction of shear force values used spectra at 1 day PM to predict shear force at 1 day which gave a root mean square error of prediction (RMSEP) of 13.6 (Null = 14.0) and the R2 between observed and cross validated predicted values was 0.06 (R2cv). Overall, for fresh LL, the predictability SF, by either the Raman hand held probe or traditional predictors was low.