Differentiation of perirenal and omental fat quality of suckling lambs according to the rearing system from Fourier transforms mid-infrared spectra using partial least squares and artificial neural networks analysis.

Fourier transform mid-infrared (FT-IR) spectroscopy was evaluated as a tool to discriminate between carcasses of suckling lambs according to the rearing system. Fat samples (39 perirenal and 67 omental) were collected from carcasses of lambs from up to three sheep dairy farms, reared on either ewes milk (EM) or milk replacer (MR). Fatty acid composition of the samples from each fat deposit was first analyzed and, when discriminant-partial least squares regression (PLS) was applied, a perfect discrimination between rearing systems could be established. Additionally, FT-IR spectra of fat samples were obtained and discriminant-PLS and artificial neural network (ANN) based analysis were applied to data sets, the latter using principal component analysis (PCA) or support vector machines (SVM) as processing procedure. Perirenal fat samples were perfectly discriminated from their FT-IR spectra. However, analysis of omental fat showed misclassification rates of 9-13%, with the ANN approach showing a higher discrimination power.

Carcass characteristics of suckling lambs protected by the PGI "Lechazo de Castilla y León" European quality label: Effect of breed, sex and carcass weight.

In the Region of "Castilla y León" (Spain), as in other Mediterranean areas, fresh suckling lamb meat is regarded as having a high edible quality. The EU granted this product a Protected Geographical Indication (PGI) "Lechazo de Castilla y León" in 1999. In this study, several carcass characteristics of suckling lambs protected by this PGI were determined, while the effects of breed, sex, and carcass weight were studied. Some differences in carcass characteristics within the three PGI authorized breeds have been detected. Neither carcass weight nor conformation measurements were good predictors of the composition of the PGI protected suckling lamb carcasses. The best predictors were fatness and composition of the leg and loin tissues, although dissection of these joints is not feasible on a daily basis. Lastly, some differences, due to sex and weight were identified in conformation, fat percentage, jointing and joint composition. Differences were, however, rather small, due to the lambs' young age and low variation in carcass weight.

Characterization of micrococcaceae isolated from salt used for Spanish dry-cured ham.

The microbial flora of salt used in the production of Spanish dry-cured ham was studied. The results indicated that Micrococcaceae constituted the predominant flora. Identification of the 369 isolates belonging to the family Micrococcaceae revealed that 60% belonged to genus Staphylococcus, 25% to Micrococcus, 6% to Kocuria, 5.4% to Dermacoccus and 0.5% to Stomatococcus. The species most often isolated was Staph. xylosus (28.9%), followed by M. lylae (21.4%), Staph. equorum (18.55%) and D. nishinomiyaensis (5.4%). The results indicate that the salt during salting process of dry-cured hams offers an ecosystem suitable for the survival of the staphylococci and micrococci.

The effect of paprika, garlic and salt on rancidity in dry sausages.

Eight batches of ground fat and eight batches of a mixture of meat and fat (70 and 30%, respectively), were prepared by adding salt, paprika and garlic, in the proportions used for making chorizo - a dry fermented sausage - stuffed into natural casings and then ripened. The evolution of rancidity in these products was evaluated by means of total free fatty acid content, peroxide value and TBARS during the ripening period. Spanish paprika and salt showed antioxidant and prooxidant properties, respectively. Paprika was even able to inhibit the prooxidant effect of salt. Also, four batches of chorizo were made to compare the antioxidant effect of the spices (garlic and paprika) with a mixture of nitrate, nitrite and ascorbic acid. In this respect, paprika and garlic were as effective as the mixture of additives in inhibiting lipid oxidation.

Changes in proteins during the ripening of Spanish dried beef 'Cecina'.

Changes in the solubility of sarcoplasmic and myofibrillar proteins were tracked in Semitendinosus and Rectus femoris muscles during the ripening process of Spanish 'Cecina'. The extractability of both types of proteins decreased during the ripening. This phenomenon was more marked in the initial stages of processing. Electrophoretic studies of the myofibrillar proteins showed the virtual disappearance of the myosin heavy chain, troponin C and myosin light chain 2 from the smoking phase onward and the appearance of three components of molecular weight of about 65, 70 and 75 kda during ripening. The remaining proteins did not suffer appreciable changes.

Bovine skeletal muscle adenosine deaminase: kinetic and thermodynamic studies.

Adenosine deaminase from bovine skeletal muscle catalyzes the hydrolytic deamination of adenosine to inosine and ammonia via an ordered Uni-Bi mechanism, if water is not considered as a true second substrate, as deduced from the inhibition pattern products. The inhibition constants (Ki) obtained for inosine and ammonia were 316 mumol/l and 2 mol/l, respectively. The activation energy of the reaction has been calculated as 10 kcal/mol, delta H* and delta F* as 7.9 and 15.6 kcal/mol, respectively, and delta S* as -23 cal/mol/degrees K.

Changes in several constituents during the ripening of 'Chorizo' - A spanish dry sausage.

'Chorizo', a dry fermented sausage marketed in Spain, is traditionally prepared without curing agents or sugars. In order to establish the fermentation process batches A (with added sugars) and B (traditional process) were prepared. pH, carbohydrate disappearance, cured meat pigment formation, free fatty acids (FFA), non-protein nitrogen (NPN) and NH(4)(+) were determined through 100 days of ripening. In batch A, cured meat pigment formation, pH decrease and NPN evolution were greater than in batch B, whereas FFA and NH(4)(+) were similar. Garlic and Spanish paprika added to the mixture introduced significant amounts of fermentable carbohydrates (0·68%) and approximately 16 ppm NO(3)(-).

Bovine skeletal muscle adenosine deaminase. Purification and some properties.

A low molecular weight form of adenosine deaminase from bovine skeletal muscle was purified about 930-fold. The enzyme had a mol. wt of 31,000, a Km value for adenosine of 2.37 X 10(-5) M and a pH optimum at 7.0. This enzyme is very resistant to heat inactivation and does not require metal activators or other dialysable cofactors. A possible role in the post-mortem metabolism of adenine nucleotide in skeletal muscle is discussed.