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Technological and nutritional properties of ostrich, emu, and rhea meat quality
2016
Horbańczuk, Olaf K. | Wierzbicka, Agnieszka
In recent years a growing demand for ratite meat, including ostrich, emu, and rhea has been observed all over the world. However, consumers as well as the meat industry still have limited and scattered knowledge about this type of meat, especially in the case of emu and rhea. Thus, the aim of the present review is to provide information on technological and nutritional properties of ostrich, emu, and rhea meat, including carcass composition and yields, physicochemical characteristics, and nutritive value. Carcass yields and composition among ratites are comparable, with the exception of higher content of fat in emu. Ostrich, emu, and rhea meat is darker than beef and ratite meat acidification is closer to beef than to poultry. Ratite meat can be recognised as a dietetic product mainly because of its low level of fat, high content of polyunsaturated fatty acids (PUFA), favourable n6/n3 ratio, and high iron content in comparison with beef and chicken meat. Ratite meat is also rich in selenium, copper, vitamin B, and biologically active peptides such as creatine (emu) and anserine (ostrich), and has low content of sodium (ostrich). The abundance of bioactive compounds e.g. PUFA, makes ratite meat highly susceptible to oxidation and requires research concerning elaboration of innovative, intelligent packaging system for protection of nutritional and technological properties of this meat.
Afficher plus [+] Moins [-]Influence of post-mortem muscle glycogen content on the quality of beef during aging
2016
Onopiuk, Anna | Półtorak, Andrzej | Wierzbicka, Agnieszka
Introduction: Glycolic changes which occur post-mortem have an impact on the physical and sensory features of beef, which in turn determine the successive processes and influence such beef quality traits as colour, tenderness, and cooling loss. The aim of this study was evaluation of the post-mortem changes in bovine meat during aging, quantitative analysis of glycogen and lactic acid, as well as examination of their impact on technological and sensory quality of selected muscles from Holstein-Friesian × Limousin breed carcasses.Material and Methods: The study included three muscles of different metabolic qualities and sarcomere length: m. semitendinosus, m. longissimus dorsi, and m. psoas major, collected from nine bull carcasses aged 24 ±2 months.Results: Significant correlations were found between the volume of cooling loss on individual days of aging and the pH value of muscle tissue, lactic acid and glycogen content, as well as beef lightness. However, no significant dependency between the volume of glycogen and the intensity of red and yellow colours was detected.Conclusion: The colorimetric analysis of glycogen and lactic acid can be an effective tool in predicting the quality of beef.
Afficher plus [+] Moins [-]Impact of early castration and health status on the performance of Holstein-Friesian and beef crossbred calves
2016
Wielgosz-Groth, Zofia | Sobczuk-Szul, Monika | Nogalski, Zenon | Purwin, Cezary | Pogorzelska-Przybyłek, Paulina | Winarski, Rafał
Introduction: This article presents the analysis of the correlation between the category and health status of calves and the results of their rearing and levels of selected blood parameters.Material and Methods: The study included 105 Polish Holstein-Friesian and beef (Limousine, Charolaise and Hereford) crossbred calves. Young bulls were purchased at the age of two to four weeks. The animals underwent quarantine, were dehorned, and 46 young bulls were castrated. The germ horns were removed by burning out. Castration was carried out with a bloodless method using a rubber band. The calves were kept in groups and fed a milk replacer administered via teats from automated milk-feeding stations. After the period of milk feeding, the calves were fed grass silage ad libitum and a concentrate at 2.5 kg/animal/day. The calves were weighed every two weeks. Blood for analyses was sampled at 43 d of age.Results: After the rearing period finished at the age of six months, young bulls and steers had similar body weights (176.17 and 176.55 kg) and approximate average daily weight gains from birth (0.756 and 0.767 g/day). The healthy calves at six months of age weighed 180.47 kg, whereas the animals which at least once suffered from some diseases during rearing were lighter by approx. 30 kg (P ≤ 0.01). A statistically significant (P ≤ 0.01) difference was found for the count of red blood cells and white blood cells. In comparison with healthy individuals, the diseased animals had less RBC (8.33 and 9.42 10¹²/L respectively) and more WBC (27.03 and 12.26 10⁹/L respectively).Conclusion: Castration of young bulls did not have any impact on the results of rearing and health status of the calves. The magnitude of the analysed parameters depended on the health status of the calves. Thus RBC and WBC parameters may be used to predict the health status of calves during rearing.
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