Pierre Picouet

Application of computed tomography (CT) in meat science is based on the different X-ray attenuations that tissues of different density produce. Processed data generate images (tomograms) where different biological structures may be distinguished. CT is of special interest for the study of the meat curing processes since a high density of salt ions produce a marked increase of CT attenuation values. Therefore, salt diffusion and distribution can be easily followed throughout the process. In this study, prediction models for salt and water content in dry-cured ham have been developed, obtaining errors of prediction of 0.3% NaCl and 1.5% water. Fat content and drying level significantly affect the precision of salt and water content predictions. A certain underestimation of salt content in fatty samples was observed. CT and the developed predictive models may be useful in the meat industry as a tool for characterizing and optimizing salting processes.

Pig carcasses (122 half carcasses, 52 hams and 52 loins) from the Spanish pig population, were obtained in a commercial slaughterhouse and scanned by computed tomography to generate a predictive model determining weight and lean content. The model is mainly based on a density correction equation. The weight prediction model used the area of the histogram of the whole half carcass in a range of -250 to +800 Hounsfield units added to 2769g corresponding to the average weight of the head and pig feet that have not been scanned. The lean content predictive model is based on the ratio between the area of the lean peak in the calculated histograms and the area of the histogram of the whole half carcass. Both models were correlated with a manual dissection of the samples. Results from the predictive models and from the dissection were compared with the calculation of the root mean square error of calibration (RMSEC) for weight determination and lean content. Results show that a RMSEC of 0.6kg can be obtained for the weight half carcass. For prediction of the lean meat percentage a RMSEC of 1.48% can be obtained for the carcasses, 0.97% for the ham and 1.07% for the loin. According to our results, with a simple methodology it is possible to have good prediction values of weight and lean percentage in accordance with EU regulation.

Silver nanoparticles have been formed in fluff pulp and nanostructured Lyocell fibres by immersion in silver nitrate, and a subsequent transformation of the adsorbed silver ions into elementary silver nanoparticles by physical (thermal/UV) or chemical (sodium borohydride) methods. ...

Tetracycline (TC) and 4-epitetracycline (4eTC) degradation, as well as anhydrotetracycline (ATC) and 4-epianhydrotetracycline (4eATC) formation, has been evaluated in thermally treated chicken breast, pig loin, and pig loin with added back-fat. Samples containing TC and 4eTC residues were submitted to microwave or boiling heating, extracted with a mixture of McIlvaine buffer/methanol (75:25), and analyzed by high-performance liquid chromatography-diode array detection on a phenyl-hexyl reverse phase chromatographic column. The formation of ATC and 4eATC, as well as of two unidentified compounds, was described for the first time in edible meat samples submitted to mild thermal treatments, similar to those applied at home to cook foods. Degradation of TC and 4eTC and formation of ATC and 4eATC versus time of treatment fitted satisfactorily a first-order kinetic. Even if the potential toxic effects of these breakdown compounds should be further investigated, their formation in cooked meat should be taken into account when maximum residue limits are established.