Effect of IGF-II (insulin-like growth factor-II) genotype on the quality of dry-cured hams and shoulders

Classifying different Iberian pig genetic lines by applying chemical-instrumental parameters of dry-cured Iberian shoulders

Iberian pigs are an autochthonous porcine breed mainly bred in southwestern of Iberian Peninsula, this herd traditionally feeds on acorn and pasture, in an extensive production system. In this study, the main objective was for classifying Iberian shoulders from different genetic lines of pigs and their crossed genetic lines. For that, morphology parameters, fatty acid profile and volatile compounds were determined on two batches of dry-cured Iberian shoulders. The samples were acquired from the same place of the dry-cured Iberian shoulders. From these data, two databases were created, for training and validation purpose. Results on this study, firstly demonstrate the capability of data mining techniques in order to classify shoulder as function as Iberian pig genetic lines by using of different quality characteristics. Four classification models were developed and tested in the training database and all models achieved a percentage of correct classification higher than 75%. Then, the same four classification models were performed in the validation database and the model of J48 decision tree and fatty acid profile reached the highest correct classification percentage (91.67%), and from Retinto genetic line (95.65%). From this classification model, a software application was developed in order to determine in a semi-automatic way the genetic line of the dry-cured Iberian shoulder. This application could be used in the meat industries for determining relationships between genetic line and meat quality or performance of noble parts.

Amino acid and nucleotide contents and sensory traits of dry-cured products from pigs with different genotypes

The free amino acid and nucleotide contents of dry-cured ham, shoulder and loin from two genetic lines selected from pigs according to the paternal allele (homozygous AA and heterozygous AG) of the insulin-like growth factor-II gene were studied by HPLC. Their influence on the flavor and taste characteristics was also studied. The increase of lean content caused by the IGF-II mutation could affect proteolysis during the ripening process and therefore the sensory characteristics. The lower intramuscular fat content in the AA ham batch had a positive effect on the free amino acid content. However, similar flavor traits between ham batches were found, but the AG loin batch showed greater value. The enhancing effect of the IMP on the overall flavor intensity was limited by the amino acid and the IMF contents in dry-cured ham and loin, while in dry-cured shoulder, the IMP could be the reason for the significant differences in after taste and cured flavor scores.