Sensory characteristics of meat and meat products from entire male pigs.

The surgical castration of male piglets has traditionally been practised to prevent the development of boar taint in pork meat, but European rules aim to end this practice on a voluntary basis. This study represents a sensory characterization of the meat and meat products from entire male pigs. Three levels of androstenone concentration in fat were compared: low, 0-0.3mgkg-1; medium, 0.4-0.9µgkg-1 and high, 1-2.75µgkg-1. The use of meat from entire males in meat products lowered the perception of boar taint compared with fresh meat but was insufficient to totally mask it. Androstenone levels seem to influence the intramuscular fat content and hence, on texture. The perception of boar taint in meat products depends on androstenone concentration as well as on the characteristics of the product. It is necessary to develop additional strategies to totally mask androstenone perception in meat and meat products.

A procedure for sensory detection of androstenone in meat and meat products from entire male pigs: Development of a panel training.

This study represents a proposal for training sensory panels in androstenone (AND) perception in meat and meat products. The procedure consists of four main parts: (1) selection and training of a sensory panel (11 panelists) using standards with Vaseline oil media as carriers of AND and skatole (SKA); (2) developing a training method AND detection in meat; (3) dry cured meat product and (4) cooked meat product. All candidates were able to distinguish between AND, SKA and AND+SKA in Vaseline oil, order AND solutions with different concentrations and classify them in the three categories: low, medium and high. The panel was able to differentiate the meat in the three categories, but only the high level in meat products. Due to the individual features in AND perception, specific training for each type of product is required.

Phase I metabolism of 3-methylindole, an environmental pollutant, by hepatic microsomes from carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss).

We studied the in vitro metabolism of 3-methylindole (3MI) in hepatic microsomes from fish. Hepatic microsomes from juvenile and adult carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss) were included in the study. Incubation of 3MI with hepatic microsomes revealed the time-dependent formation of two major metabolites, 3-methyloxindole (3MOI) and indole-3-carbinol (I3C). The rate of 3MOI production was similar in both species at both ages. No differences in kinetic parameters were observed (p = 0.799 for Vmax, and p = 0.809 for Km). Production of I3C was detected only in the microsomes from rainbow trout. Km values were similar in juvenile and adult fish (p = 0.957); Vmax was higher in juvenile rainbow trout compared with adults (p = 0.044). In rainbow trout and carp, ellipticine reduced formation of 3MOI up to 53.2% and 81.9% and ketoconazole up to 65.8% and 91.3%, respectively. The formation of I3C was reduced by 53.7% and 51.5% in the presence of the inhibitors ellipticine and ketoconazole, respectively. These findings suggest that the CYP450 isoforms CYP1A and CYP3A are at least partly responsible for 3MI metabolism. In summary, 3MI is metabolised in fish liver to 3MOI and I3C by CYP450, and formation of these metabolites might be species-dependent.

Myostatin and insulin-like growth factor-1 in hypertensive heart disease: a prospective study in human heart donors.

OBJECTIVE: The physiopathological mechanisms implicated in hypertensive heart disease are multi-factorial, including myocyte hypertrophy, apoptosis and myocardial remodelling. In this process, some hormonal and local growth factors have a regulatory influence. The aim of this study was to evaluate the potential role of myostatin and insulin-like growth factor-1 (IGF-1) myocardial expression in the development of hypertensive-induced cardiac damage. METHODS: Samples of human myocardium tissue from organ donors were prospectively collected and classified according to the presence of hypertension, alcohol consumption, other causes of myocardial damage and the presence of structural cardiomyopathy (CMP). Myocardial samples were studied by immunohistochemistry and myostatin, and IGF-1 myocardial expression was evaluated in all the different groups of donors. Hypertensive donors were compared to other groups. RESULTS: A total of 66 heart samples from human donors were collected: 33 donors had no previous or present history of hypertension and 33 donors presented defined hypertension. Donors with hypertension presented higher myocyte cell and nuclear hypertrophy and showed similar myostatin myocardial expression as controls, but lower IGF-1 myocardial expression. Myostatin expression was significantly higher in hypertensive donors with CMP compared to non-hypertensive healthy donors. The presence of CMP of diverse origin (alcoholic, valve and coronary) also significantly increased myostatin myocardial expression. CONCLUSION: The presence of hypertension significantly decreases IGF-1 myocardial expression. Myostatin myocardial expression increases in the presence of structural CMP either of hypertensive or other origin. These effects open the possibility of modulating hypertensive-induced cardiac damage.

Insulin-like growth factor 1 myocardial expression decreases in chronic alcohol consumption.

BACKGROUND: Alcoholic cardiomyopathy (CMP) is one of the major complications of chronic excessive alcohol consumption. The pathogenic mechanisms implicated are diverse, inducing functional and structural changes in the myocardium. Insulin-like Growth Factor 1 (IGF-1) plays an important role in modulating the cell cycle, and helps the differentiation and proliferation of cardiac tissue inhibiting apoptosis. Experimental studies have suggested the role of IGF-1 in alcohol-induced cardiac damage. The aim of the present study was to determine the effect of chronic alcohol consumption on IGF-1 myocardial expression and to compare this expression in cases of hypertension and other cardiac diseases. METHODS: We studied heart samples from human organ donors: 10 healthy donors, 16 with hypertension, 23 with chronic alcohol consumption and 7 with other causes of cardiac disease. IGF-1 myocardial expression was evaluated with a specific immunohistochemistry assay using a semi-quantitative method. RESULTS: A significant decrease in IGF-1 myocardial expression was observed comparing all the cases included with control donors. This decrease in IGF-1 myocardial expression was significantly lower in the group of donors with chronic alcohol consumption compared to controls. On group evaluation according to the presence of CMP, donors with chronic alcohol consumption without CMP presented significantly lower IGF-1 expression than controls, whereas donors with chronic alcohol consumption with CMP showed a downward trend without achieving significance. CONCLUSIONS: Chronic alcohol consumption significantly reduces IGF-1 myocardial expression. This decrease induced by alcohol is partially compensated in the presence of structural myocardial damage.