MRI-based analysis of feeding background effect on fresh Iberian ham

This paper describes the Magnetic Resonance Imaging (MRI) contrastive analysis of Iberian hams from pigs that have been fattened only with acorns and grass (AG) and those that have been fattened with high oleic acid concentrates (HO). Based on computer vision techniques, the implemented methods of image processing allowed for the automatic recognition of the Biceps femoris muscle as well as for computational texture feature detection in the muscle. The data collected was then checked against physical–chemical composition. The MRI sequence obtained displayed markedly visual differences in terms of the grey hue for both muscle (darker in AG-fed hams) and inter-muscular and intra-muscular fat (darker in HO hams). Most computational texture characteristics proved to be statistically different between the AG and HO image sets. Two groups (G1 and G2) of texture features were derived. G1 was closely related to linolenic acid (C18:3 n-3) and γ-tocopherol, defining Iberian ham of AG pigs, while G2 was associated with HO pigs. Thus MRI-based analyses enable visual distinction of Iberian hams according to the feeding background. This distinction is also achieved computationally via the examination of the texture features in the muscles.