The Study On Relationships Between Marbling And Meat Colour And Beef Qualities

Because of their high protein content, low-fat content beef has always been a preferred consumption of meat in Western countries. After years of development, animal agriculture in developed Western countries gradually formed a perfect fit for their situation of beef grading standards. As our people's standard of living continues to improve, people came to shift consumption from pork to beef of a higher nutritional value, suitable for the situation of our country beef quality assessment technology in the course of continuous development. When an ordinary consumers first when you see a piece of beef, its most intuitive is the first impression of marbling, fat color and meat color, these three indicators are also the beef grading basis at home and abroad. However our beef grading market remains muddled brings a lot of damage to businesses and consumers. Simmental crossbred cattle for this thesis research, systematic study of marbling, natural color and fat of these three indicators on the quality of beef, guiding consumers understanding beef quality, beef quality evaluation technologies for the development of appropriate national conditions provide a theoretical basis.Chapter 1:The relationships between marbling of beef longissimus dorsi and functionalities were investigated. Five grades were choosen. The content of protein and water significantly declined with the grades increased (P<0.05), but the content of IMF and CLA were significantly increased (P<0.05). Results showed that significant differences were found in sensory attributes (P<0.05), marbling contributes a lot to the flavor,juiciness,tenderness and overall evaluation. The Grade S and Grade A beef significantly better than Grade B and C beef on sensory quality. But the marbling grade when they reach the S (that is, around 14% of intramuscular fat content), enough to meet the needs of beef eating quality when the intramuscular fat content increased when it comes to 17%, it will cause a marked reduction in sensory evaluation results.Chaper 2:The relationships between beef longissimus dorsi color and functionalities were investigated. Four types of color grades were choose:bleached red, cherry red, dark red and dark. The pH significantly increased with the color darken (P<0.05). Results showed that no significant differences were found in nutrition and sensory attributes (P>0.05), while there were significant differences in functionalities. The gel strength, gel elasticity, gel water holding capacity and cook loss of dark, firm and dry beef were better than the other three types of grades(P<0.05), but its emulsifying capacity was the weakest(P<0.05).Chaper 3:The relationships between the fat colour of beef longissimus dorsi and functionalities were investigated. Four types of color grades were choose:white,milky white, light yellow and yellow. Analysis the difference of sensory quality and nutritional value such as content ofβ-carotene, lutein, CLA, water,protein. In terms of sensory quality, white and milky white fat meats have an advantage over light yellow and yellow fat meat, their cooking loss, tenderness and shear stress significantly better than light yellow and yellow fat meat (p<0.05). Nutritional value, the content of CLA and carotenoids of light yellow and yellow group significantly higher than the white and milky white group(p <0.05),no significantly differences were found on water,protein and fat content(P>0.05), light yellow and yellow groups have an advantage in terms of nutritional value than white and milky white groups.