말근육 부위별 근섬유 특성 및 등급판정에 따른 육질분석

Abstract

Recently the number of livestock horses being raised for horse racing and riding is on an increasing trend. But there is also a need to address the number of horses that are not being use for racing or riding, which has reached 3,249(12.6%). One method is to slaughter these horses that are not currently fulfilling a particular purpose for meat consumption, which aligns with the current yearly increasing trend of meat consumption in Korea. Horse meat is known for its good nutritional balance with a low and unsaturated fat content and relatively high essential amino acid composition. But because the horses used in the horse meat market industry, are horses that are bred for racing and riding and then retired to be slaughtered for meat consumption, the quality of the meat is inferior and although the meat is evaluated and certified accorind to meat grade standards, because there is no general criteria on the grade evaluation of horse meat carcasses and because there is little motivation for rural Korean farmers to produce high quality meat, the reality is that it is difficult to provide high quality horse meat to consumers. This research has the objective of examining the quality of horse meat according to the meat grade system and also the quality of horse meat being sold on the market with the objective of increasing the quality of horse meat and to develop a certification system to improve the meat characteristics and competitiveness of horse meat. This research also has the objective to serve as reference as basic data for establishing the optimal fattening conditions for high quality horse meat production. To configure the optimal fattening duration to produce high quality horse meat according to the fattening duration, analysis was conducted on the quality of meat, and the test groups used for the quality of meat analysis according to fattening duration were 18 Jeju grown horses and 18 Jeju and thoroughbred crossbred horses, and the horses were fed an amount of concentrated fodder that was 1.5% of the weight of the horses for feed in addition to bulk food that was fed freely. Filter paper fluid uptake, which is an indicator for water holding capacity, was shown not to have a significant difference during the fattening duration. 24 drip loss was in the range of 1.76±0.54∼4.04±3.98(%) and showed the highest amount of meat moisture content loss in the 8th month of fattening at 4.04±3.98(%), and the water loss amount was the smallest at 3, 4 and 7 months at 15.66±4.61(%), 1.76±0.54(%), 1.93±0.52(%), respectively. (P<0.05) The value of cooking loss was also shown to be the highest in the 8th month of fattening at 21.00±1.72(%) and the meat moisture loss was the smallest at 3, 4 and 6 months at 15.66±4.61(%), 16.13±4.81(%), 14.98±4.02(%), respectively. (P<0.05) The range of the cooking loss value was shown to be 14.98±4.02∼21.00±1.72(%). The values of lightness (L*), redness (a*), yellowness (b*), which indicate the meat color, did not show significant differences. By collecting the quality of meat characteristics of the horse carcass before fattening according to the usage of the meat, while there were significant differences in 24 hour pH, ffu and meat color, in the horses that were used for riding before fattening the pH, ffu and Drip loss showed the highest values at 4.24±3.40(%) and cooking also showed the high loss of meat moisture at 20.73±4.47(%). (P<0.05) To examine the characteristics of the meat according to the current meat grade certification results, 59 horses raised in Jeju were categorized into 1+, 2, 3 meat quality grades and A, B, C carcass yield grades for the research. While the 24 hour pH, ffu and meat color according to quality of meat showed significant differences, for water holding capacity the drip loss value showed the lowest value in the 1+ grade at 0.92±0.56(%) and for cooking loss the 1+ grade was shown to have the lowest value at 10.69±5.44(%). Meat texture analysis was conducted according to the quality of meat grade and in the 1+ grade the hardness value was shown to be the lowest at 27.18±11.99(N) and there were no significant differences for the values of cohesiveness, springiness, adhesiveness, gumminess, chewiness and resilience. An analysis of the quality of meat according to the carcass yield of meat did not show a significant difference in the 24 hour pH, water holding capacity, meat color and meat texture. The analysis of meat quality for meat breed showed that in the cross breed of Jeju horse and thoroughbred, the quality was higher than that of the pure thoroughbred at 5.59±0.21 compared to 5.40±0.03. (P<0.05) While there was no significant difference for the ffu value, the drip loss values for the Jeju and thoroughbred cross breed was lower than that of the thoroughbred breed at 1.63±2.33(%) compared to 2.75±0.41(%) and for the cooking loss value it was shown that the Jeju and thoroughbred cross breed was lower than that of the Jeju breed and the thoroughbred breed at 12.13±4.66(%) compared to 18.08±2.88(%) and 19.91±1.35(%). (P<0.05) There were no significant differences for meat color. The results of analyzing the meat texture for each breed showed that the hardness value of the thoroughbred breed was lower than that of the Jeju breed and the Jeju and thoroughbred cross breed at 28.49±4.56(N) compared to 32.35±8.57(N) and 33.28±3.24(N). (P<0.05) For the quality of meat analysis for gender of horse, there were no significant differences for pH, water holding capacity, meat color and meat texture. The histological characteristics for each muscle group of the horse were examined. The muscle fiber area ratio and fiber ratio for each muscle group were measured and the TypeⅠ ratio was shown to be the highest in the Triceps muscle , and the TypeⅡb ratio was shown to be the highest in the Semimemb rannosus. As a result of examining the size of the muscle fibers it was shown that the TypeⅡb muscle fibers were larger than the Type I muscle fibers in all muscles with the exclusion of the Longissimus dorsi muscle. It was shown that the muscle fiber size was the largest in the Biceps femoris muscle. The post test pH change of the Jeju raised horses showed that after slaughtering the pH consistently dropped for 7 hours to 6.1 and then up to 19 hours the pH was shown to decrease at a slower rate. L* 1h and pH for 3h and 6h showed a correlation of –0.803, -0.664, respectively (P<0.05) and in the L* value the initial post test for 1, 3, 6, 9 hours the pH value showed a correlation of –0.625, -0.751, -0.807, -0.941, respectively. From this result it is determined that there is a negative correlation between the initial pH and the L* value. The 24 hour drip loss value for post test 1 and 3 hour showed a correlation of –0.686, -0.404, respectively, and from this result it is determined that the lower the post test pH is, the higher the drip loss value will rise to. As a result of analyzing the correlation between the muscle fiber area ratio and the quality of meat, a correlation between the Type Ⅰ area and the 24 hour pH was discovered and there was also a correlation between the 1 hour pH and redness of 0.933. (P<0.05) For the TypeⅡa and TypeⅡb muscle fibers that go through anaerobic metabolism, there was a correlation between the muscle fiber area and the post test initial 9 hour pH. (r=-0.963, -0.798. and P<0.01, 0.05, respectively) The cross sectional area of TypeⅡb muscle fibers and the 24 hour L* showed a correlation of 0.688. (P<0.05) The results of this research show that according to the use of the horse before fattening for meat consumption there can be a resulting difference in water holding capacity for the meat. It was confirmed that the grade of the carcass yield of the meat did not influence the quality of the meat, and it was confirmed that the 1+ grade meat had superior water holding capacity and tenderness. But because it is characteristically difficult for Jeju breed horses to have fat marbling in the muscle, the occurrence of 1+ grade meat is rare. Therefore it is considered to be necessary to design a system to produce high quality horse meat.