Evaluation of the electrical impedance spectroscopy (EIS) equipment for ham meat quality selection

The objective of this study was to evaluate the electrical impedance spectr oscopy (EIS) prototype, to select the hams on the basis of meat quality cha racteristics in commercial conditions. Measurements of meat quality were ma de on 95 commercial hams (11.10+/-0.76 kg) to evaluate quality characterist ics [ham weight, conformation (H), fat thickness in the rump (FTR), visual fatness (VF), pH(45), electrical conductivity (QM(45)) and ultimate pH (pH( 24), pH(36)) in the semimembranosus muscle]. The electrical parameters, Ro, Rinf, Ratio (Rinf/Ro), Fc and alpha, were obtained with the EIS equipment and was applied in five different regions of the ham (M, SM, M1, M2 and AD) at 36 h post-mortem. Principal component (PC) analysis has been used to de scribe the relationships between meat quality and electrical parameters in the ham meat. Two regions were selected, SM and M, showing the best correla tions with pH(45) and fat characteristics in relation to electrical paramet ers Rinf and Ratio, respectively. Multiple regression analysis of the data confirmed that electrical variables, Ratio, alpha and Fc contributed to pre dict pH(45) (R-2 = 0.50). In order to better predict visual fatness (VF), c onformation and ham weight were included in the multiple regression. A R-2 of 0.59 was obtained with H, Rinf, ham weight and alpha. In conclusion, the results of this study have demonstrated that ratio in the SM region may cl assify with 88.46% accuracy the technologically normal meat (pH(45) > 6.10) from the PSE meat. In relation to visual fatness of the ham 84.21% of the samples with a Rinf in the M region > 56 had a score of a 2.5. (C) 2001 Els evier Science Ltd. All rights reserved.