Green hams electrical impedance spectroscopy (EIS) measures and pastiness prediction of dry cured hams

The objective of this study was to assess the value of electrical impedance spectroscopy (EIS) as a predictor of certain dry-cured ham sensory properties in green hams of different technological meat qualities and processed commercially. Measurements of technological meat quality (weight, ham conformation, subcutaneous fat thickness, pH45 and pHu) and some sensory properties (adhesiveness, hardness, crumbliness, pastiness, fibrousness and saltiness) were carried out on the Biceps femoris (BF) and Semimembranosus (SM) muscles. The electrical parameters, Ro, Rinf, ratio (Rinf/Ro), Fc and α, were obtained with EIS equipment applied to two different regions of the ham at 36 h post mortem (BF and SM). Principal component (PC) analysis was used to describe the relationship between sensory properties and electrical parameters. For BF muscle there were no clear relationships between the electrical parameters and the sensory properties. However, for SM muscle, pastiness was correlated positively with the ratio and Fc obtained by EIS. None of the electrical parameters obtained by EIS were able to differentiate between groups of hams classified according to their level of pastiness in the BF muscle. However, in the SM muscle, the origin of the pastiness was related to the use of PSE meat and was predicted by the electrical impedance measurements. The EIS prototype correctly detected 69.2 and 56.0% (for SM and BF muscles, respectively) of the problem hams in terms of pastiness. These results could be of use in the selection of the raw material to reduce the incidence of dry-cured hams with defective texture.