基于超声成像技术的冷鲜与解冻牛肉鉴别方法

Discrimination of Fresh and Frozen-thawed Beef Based on Ultrasound Imaging

针对市场上存在以解冻牛肉冒充冷鲜牛肉售卖的问题,研究了利用超声成像技术对冷鲜与解冻牛肉进行质构分析与鉴别的可行性。首先,通过超声成像设备采集冷鲜与解冻牛肉超声图像信息,并结合质构参数、微观结构和部分理化指标分析图像差异成因。然后,采用灰度共生矩阵法提取图像纹理特征值,利用主成分分析法进行数据降维处理,分别建立线性判别分析(Linear discriminant analysis,LDA)和支持向量机(Support vector machine,SVM)两种判别模型。结果表明,两种判别模型均有较好的分类效果,其中LDA模型更优,当主成分数为5时,模型的训练集和测试集识别率均达到100%。说明应用超声成像技术对冷鲜与解冻牛肉进行质构分析与鉴别是可行的。

Fresh beef is more expensive than frozen-thawed beef for its good quality and taste.Some unscrupulous traders labeled frozen-thawed beef as fresh beef for sale.The feasibility of using ultrasonic imaging technology to analyze and identify fresh and frozen-thawed beef was studied.Firstly,the texture,microstructure and some physical and chemical indexes of the fresh and frozen-thawed beef were collected to analyze their differences.Secondly,a total of 60 ultrasound images of fresh and frozen-thawed beef were collected by ultrasound imaging system.Twenty common texture characteristic values defined by grey level cooccurrence matrix were collected.Then,principal component analysis(PCA)for data dimension reduction was used,and linear discriminant analysis(LDA)and support vector machine(SVM)were used to discriminate the samples.The result showed that there were significant differences(P<0.01)in texture index,L^*and cooking loss between fresh and frozen-thawed beef.These differences combined with microstructural images showed that the tissue structure of frozen-thawed beef was damaged and the internal texture of frozen-thawed beef was poor.The ultrasound images of fresh and frozen-thawed beef showed significant differences,which could be well explained by the above studies.The texture features of the ultrasound image of fresh and frozen-thawed beef were significantly different(P<0.01).Both LDA and SVM had good discriminant results,especially LDA.When principal component signals were five,the precision rates of train set and test set of LDA were both 100%.The results showed that it was feasible to distinguish the fresh and frozen-thawed beef by using ultrasound imaging technology.