The carcass price of commercial pigs in Japan is generally determined by the carcass grade rating. However, the composite breed pigs of Jinhua and Duroc breeds (1/8 Jinhua composite) developed as a new brand pig in Shizuoka Prefecture are traded on a direct trading because the carcass evaluation standard of the new composite breed pigs has not yet been established. The aims of this study were to investigate carcass characteristics of the new breed pigs by comparing with those of commercial three crossbred pigs (Landrace, Large White and Duroc) and to develop a carcass evaluation standard for the composite breed pigs. Two types of data set were used for analysis in this study. First, carcass traits of 15 Jinhua composite breed pigs and 13 commercial three crossbred pigs kept at Shizuoka Prefectural Research Center were compared to investigate differences of carcass traits of the two breeds. Secondly, data on carcass traits and carcass prices from 440 Jinhua composite breed pigs shipped from a commercial fattening farm were used to develop multiple regression equations for predicting carcass price of the Jinhua composite breed pigs. The best multiple regression equation including carcass weight and linear and quadratic terms of backfat thickness was selected to build a prototype of the Jinhua composite breed pigs’ carcass evaluation standard. The result of the comparison between carcass traits of the two breeds showed that the Jinhua composite breed pigs had longer days to market (p<0.001) and thicker backfat thicknesses in the shoulder, back and waist regions (p<0.001, p<0.001 and p<0.05) than those of the commercial three crossbred pigs. The Jinhua composite breed pigs had smaller loin muscle area (p<0.001) but higher marbling score of the loin (p<0.001), suggesting that the Jinhua composite breed pigs had good meat quality despite of their less productivity than the commercial three crossbred pigs. The multiple regression analysis indicated that the carcass price of the Jinhua composite breed pigs was the highest at a backfat thickness of 3.17 cm. The adjusted coefficient of determination for this multiple regression equation was 0.73. Finally, based on this multiple regression equation, we could establish a carcass evaluation standard for the Jinhua composite breed pigs by using their carcass weight and backfat thickness.

Volatile fractions, i.e., strongly acidic fraction, strongly acidic fraction with fatty acid removed, weakly acidic fraction, and neutral fraction, were prepared from roasted pork longissimus muscle, and subjected to odor evaluation by a trained panel using Check-All-That-Apply questions. A total of 20 items, each checked with a probability of 0.0217 or higher, were selected to describe the odor characteristics of each volatile fraction. With the use of these descriptors, strongly acidic fraction was characterized as “sweat-like” and “beast-like,” strongly acidic fraction with fatty acid removed was characterized as “sweet” and “toasty,” and neutral fraction was characterized as “earthy,” “muddy,” “hay,” and “musty”. As fraction volume increased, the probability of these odor items being checked also increased. In weakly acidic fraction, the odor traits were intermediate, falling between the strongly acidic and neutral fractions. However, “pork-like odor” was hardly perceptible in any of the fractions. The volatile fractionation procedure and the 20 odor descriptors presented in this study can be used to identify odor characteristics and substances in pork meat.