Determining the efficacy of a biosensor to detect calpastatin, a meat tenderness indicator

An instrumental tenderness detection system that can be used at the time of grading to sort beef carcasses based on their predicted tenderness value would be a valuable tool for the beef industry. A biosensor that can accurately predict calpastatin, the inhibitor of the enzyme responsible for increased tenderness due to aging, has been investigated as a tenderness detection system. Two trials were conducted to determine the efficacy of developed biosensors. Longissimus dorsi samples from between the 12th and 13th rib of the beef carcass (n = 21 and n = 11) were extracted from beef carcasses at 0, 24, 36 and 48 h postmortem for trial one and at 0 and 48 hr for trial two. These samples were assayed for calpastatin by traditional laboratory methods and with the newly-developed biosensors. The biosensor used in trial one was an optical fiber biosensor and trial two was a capillary tube biosensor. Warner-Bratzler shear force was also performed on a steak from each carcass. In trial one, correlations were generated from each sampling period to determine the most closely correlated sampling times between the traditional assay and the biosensor. The results indicated that the measurement with highest correlations between the calpastatin and optical fiber biosensor were taken at 48 hr postmortem (r = 0.5966, P = 0.007), suggesting that this is the best time for use of the biosensor in an online grading system. While the correlation was lower for the capillary tube biosensor in trial two, there was less variation in the 0 hr capillary tube biosensor than the 0 hr pre-column (P = 0.006) and post-column optical fiber biosensors (P = 0.047), therefore this is a more promising system. This research further advances the development of the biosensor and makes online assessment of calpastatin one step closer to reality. The current biosensor would be useful in laboratory determination of the presence of biologically active calpastatin concentrations because of the reduction in time in laboratory procedure.