Meat tenderness evaluation using dual energy X-ray absorptiometry (DEXA)

Previous investigations indicated that a correlation exists between the preprocessed dual energy X-ray images of an airport security scanner and subjective tenderness in meat samples [PCT International Patent Application No. PCT/NZ01/00108, 2001. A method for the non-invasive measurement of properties of meat. Filed 11 June 2001]. We performed studies to confirm the patented claims and to pin-point the correlation factors based on unprocessed X-ray images. In two separate trials the peak shear force was determined on cooked samples as a measure of objective tenderness, and DEXA images scanned. The results of Trial 1 suggest that DEXA scans of whole steaks are suitable for tenderness estimation, as a coefficient of determination of R2 = 0.69 was calculated for a multiple non-linear regression. These results need to be considered in light of high within-steak coefficients of variation (mean = 16% and max = 27%). An additional, though weak correlation (R2 = 0.26), was found between a single DEXA parameter correlated to composition and mechanical tenderness. Apparently small sample size and scanning of cooked and frozen meat samples rather than raw steaks were at least partially responsible for the inconclusive results of the second trial, where no correlation could be found exceeding R2 = 0.12. More research is encouraged using state-of-the-art scanning techniques and optimized experimental design.