Tenderness prediction for beef using novel data analysis methods based on system dynamic and acoustic signals

The aim of this study was to investigate if vibroacoustic methods may be used for the non-destructive determination of beef during its aging process. The vibroacoustic method was based on the observation of mechanical changes in the meat during the aging process and was compared with reference data obtained by Warner-Bratzler shear force measurement as well as sensory testing of the tenderness using a ten-part scale. To evaluate the mechanical properties, transfer functions were used representing the time dependency of the signal and thus the viscoelastic behaviour. In this study, a total of 31 roastbeef samples from 16 different young bulls and two older cows were examined from day of slaughter to day 21 of cold storage with regard to their tenderness. For this purpose, vibroacoustic measurements were carried out on the unprocessed/raw meat at intervals of 1–3 days. The reference measurements using sensor technology and Warner-Bratzler shear force measurement were carried out on the first (day of slaughter) and last (21st day) day on slices of roast beef cooked with saturated steam. In the results of all three methods, the shear force measurement, the sensory test and the vibroacoustic method, showed that roastbeef from the same animal but different halves produced different results. Basically, it is possible to predict the tenderness of roastbeef by taking measurements at the beginning of the maturing process for the end of the maturing period using vibroacoustic methods: Data analysis led to a trend function that roughly reflects the actual tenderness, which is generally higher than the real tenderness represented by the shear-force measurement. In order to obtain a better resolution for recording the mechanical changes during the aging process, the measurements should be carried out at shorter intervals.