猪肉肉色评分与色度值、大理石花纹评分及肌内脂肪含量回归模型的建立

Establishment of Regression Models of Meat Color Score on Colorimetric Value,Marbling Score and Intramuscular Fat Content in Pigs

肉色给消费者最直接的视觉感受,是消费者选择肉类产品的重要指标之一。肉色的测定主要有肉色感官评分和色度测定两种方法。早期的肉色测定通常采用肉色评分,目前常采用色度仪测定。这两种方法测定的肉色不能直接比较,需要建立一个转化模型,将色度仪测定结果转化成肉色评分,但这方面的研究鲜有报道。由于肉色受到肌内脂肪含量的影响,因此在建立回归模型时需要剔除肌内脂肪含量的影响。研究以584头杜长大商品猪为研究对象,测定了肉色评分、色度值(L*、a*和b*)、大理石纹评分和肌内脂肪含量,探究肉色评分与其它测量性状之间的相关性,并建立色度值转换成肉色评分的转换模型。结果表明肉色评分与L*呈强负相关(r<-0.89),与a*、b*和大理石纹评分呈显著相关,与肌内脂肪含量的相关不显著(r<-0.014 2,P=0.733 2)。一共建立了3个回归模型,即肉色评分对L*和a*的回归(模型1),肉色评分对L*、a*和大理石纹评分的回归(模型2),以及肉色评分对L*、a*和肌内脂肪含量的回归(模型3)。这3个回归模型的校正拟合度均大于0.80,预测的准确率也都大于0.89,均可用来预测肉色评分。模型3的校正拟合度最高,其次为模型2,因此,有肌内脂肪含量时优先选用模型3,无肌内脂肪含量但有大理石纹评分时优先选用模型2。选取了预测模型后,就可以将色度值转换成肉色评分,从而实现色差仪测定的肉色与肉色评分之间的比较。

Meat color gives the most direct visual feeling to the consumer,and it is also one of the important criteria for consumers to choose meat products.Meat color is usually measured by meat color score and colorimeter.In the past,meat color scoring was the main method,but now colorimetry has been taking its place.Meat color scoring and colorimetric value can’t compare to each other directly,a regression model is needed to convert colorimetric value into meat color score.Until now,there are few research reports about the conversion.Since intramuscular fat content will affect meat color,its effect needs to be removed when establishing the regression model of meat color score.In this study,meat color score,colorimetric values(L^*,a^* and b^*),marbling score and intramuscular fat content were determined in a Duroc×(Landrace×Yorkshire)commercial population with 584 pigs.The correlations between meat color score and the other recorded traits were calculated,and the regression model of meat color score on colorimetric value,marbling score and intramuscular fat content was established.Meat color score was significantly correlated with the other recorded traits except intramuscular fat content,and the correlation with the L^* was the strongest(r<-0.89).Three regression models were established,which were regression models of meat color score on L^* and a^*(model 1),on L^*,a* and marbling score(model 2)and on L^*,a^* and intramuscular fat content(model 3),respectively.For each of the 3 models,the determinant coefficient was greater than 0.80,and the prediction accuracy was more than 0.89.The adjusted R^2 value of model 3 was the largest,followed by that of model 2,so model 3 was better than the other 2 models when intramuscular fat content was available,and model 2 was better than model 1 when intramuscular fat content was unavailable and marbling score available.After the colorimetric value has been converted into meat color score using the selected predicting model,it could compare to meat color score.