ABSTRACT
An investigation has been carried out on the effect of dietary supplementation with vitamin E and oleic acid on oxidative stability of Italian representative pork products. Fatty acid composition of deposited fat was modified in the oil supplemented groups with negative effects on fat firmness. Oil supplementation significantly increased vitamin E content of muscles, as well. Oxidative stability of fat, evaluated by TBARS and cholesterol oxides, has not shown significant differences between dietary treatments but, although the differences were not significant, the tendency was sufficiently clear, especially in salame Milano, towards a lower oxidation level in vitamin E enriched meat. Cholesterol oxidation was found to vary in general around 0.1% of total cholesterol and the only cholesterol oxides observed were 7ß-hydroxycholesterol, 5,6α-epoxycholesterol and 7-ketocholesterol. Aldehydes content and distribution appeared to be linked, firstly, to the specific processing technology of the product and, secondly, to the changed fatty acid composition.
ABSTRACT
Research has been conducted on the effects of feed supplementation with vitamin E, oleic acid (sunflower oil) and copper on some quality characteristics of pork chops. The study was based on the measurement of pH 45' and 24 hr post mortem, proximate composition, colour both objective and sensory, colour stability after packing in oxygen permeable film and protective atmosphere, copper and iron contents, vitamin E content in fresh and cooked chops, peroxide and TBARS value in raw and cooked meat, total cholesterol, cholesterol oxides and aldehydes in cooked meat, sensory evaluation of the eating quality of cooked chops and iodine number of subcutaneous fat. Vitamin E content was significantly higher with oil and vitamin supplementation. No variation has been observed in copper and iron contents. A higher stability of the colour of meat packed under modified atmosphere has been observed with increasing vitamin E content, but the same did not apply with meat packed in oxygen permeable film. No differences have been observed on fatty acid oxidative stability of fresh m. longissimus dorsi and cooked chops (peroxide and TBARS values), on cholesterol oxidation and aldehydes production of cooked chops with increasing vitamin E content. Iodine number in supplemented animals reached levels normally considered at risk for fat firmness.
ABSTRACT
An investigation has been carried out on oxidative processes of fresh and stored frozen pork and of two pork products (salame Milano and mortadella). Wholesale pork cuts (shoulder, ham trimmings, belly and backfat) were checked fresh and after frozen storage (1, 3 and 6 months). The streaky bacon was studied fresh and after scalding at 80 °C. Salame Milano and mortadella were produced with fresh and frozen raw materials and a few commercial samples were also part of the study. No real differences have been observed between commercial and experimentally produced salame and mortadella. Peroxide and TBARS values were low in all cases. Among the cholesterol oxides determined (7ß-hydroxycholesterol, 5,6α-epoxycholesterol, 7-ketocholesterol and 25-hydroxycholesterol) those dangerous for human health were either absent or their concentration was below toxic levels. The results are discussed on the light of literature reports and Italian pork products technologies.
ABSTRACT
Six formulations of salame Milano and mortadella were produced, one without antioxidants, two with sodium ascorbate (0.05-0.1 and O.2%), one with catechin, one with phytic acid, and one with sesamol. The products were studied for oxidation levels (peroxide value, TBARS, cholesterol oxides) and colour stability. The evaluation of the latter took place in conditions simulating commercial types of packaging (vacuum and modified atmosphere) and display. A significant difference emerged in colour stability. With the exception of salame Milano packed under modified atmosphere, in all cases salame and mortadella produced without Na ascorbate had significantly lower colour stability. Both in salame and mortadella, peroxide values and TBARS determination gave indications of a possible pro-oxidant effect of ascorbate 0.2% compared with an effective antioxidant activity of the other compounds tested. Cholesterol oxidation in salame appeared to be inhibited by sesamol and ascorbate while catechin was much less effective. In mortadella the prooxidant effect of Na ascorbate was confirmed. All lipid oxidation parameters, though, showed low oxidation values so that no quality nor health deficiencies could be envisaged with any of the formulations adopted. Lower colour stability scores, though, would create commercial problems.