To improve the eating quality of chicken, the physicochemical properties were examined, which serve as indicators for breeding. Thigh meat was collected from 384 chickens from seven and nine types of the jidori (free-range local traditional pedigree chickens) or broiler chickens, respectively. The principal component analysis of the physicochemical values of the jidori and broilers were arranged as different groups in the score plot. The results of multiple regression analysis of the sensory characteristics and physicochemical properties of thigh meat indicated that the tenderness decreased with the higher crude protein content and cooking loss in the jidori and increased with lower cooking loss and higher moisture and ether extract content in the broiler. The juiciness of the jidori decreased as the moisture content decreased, and that of the broiler decreased as the cooking loss and crude protein content increased. The umami of both the jidori and broiler was improved by increasing the 5′-inosinic acid content. Therefore, it was suggested that the physicochemical properties, which serve as indicators of the eating quality of chicken, differed between the jidori and broiler, and that the general biochemical components, cooking loss and 5′-inosinic acid content may serve as breeding indicators.

中文翻译：

---

作为地鸡和肉鸡肉感官特性指标的理化特性

为了提高鸡的食用品质，对鸡的理化特性进行了检测，作为育种的指标。大腿肉采集自 384 只鸡，分别来自 7 种和 9 种地鸡（散养的当地传统纯种鸡）或肉鸡。地鸡和肉鸡的理化值的主成分分析在得分图中被排列为不同的组。对大腿肉感官特性和理化性质的多元回归分析结果表明，地鸡的嫩度随粗蛋白含量和蒸煮损失的增加而降低，而随着肉鸡蒸煮损失的减少和水分和乙醚提取物含量的增加，嫩度增加。地鸡的多汁性随着水分含量的降低而降低，而肉鸡的多汁性则随着蒸煮损失和粗蛋白含量的增加而降低。通过增加5'-肌苷酸含量，地鸡和肉鸡的鲜味均得到改善。因此，建议作为鸡肉食用品质指标的理化特性在鸡鸡和肉鸡之间存在差异，一般生化成分、蒸煮损失和5'-肌苷酸含量可作为育种指标。