基于X射线成像的块冻虾净含量测定研究

Determination of block frozen shrimp content based on X-ray image

虾的净含量是块状冰冻虾的重要质量指标。基于X射线成像技术研究块冻虾中虾的净含量在线检测方法,通过对比同一模具下厚度相同、虾含量不同的块冻虾的X射线图像灰度差异,建立块冻虾图像灰度均值与虾含量相关关系,实现块冻虾中虾的净含量快速测定。研究发现,当成像参数一定时,相同厚度的虾块中,其图像灰度均值与其虾的净含量呈线性关系,且不受冰冻时间影响。分别采集了同一型号模具下30、35、40、45 mm厚度时不同含虾量的块冻虾图像,建立灰度均值与虾含量的线性方程,相关系数R2分别为0.9958、0.9983、0.9897、0.9437。对20个不同厚度、不同含虾量的块冻虾进行模型验证,当虾含量在100 g以上时,绝对误差0.03~36.5 g,相对误差0~14%;当虾含量100 g以下时绝对误差7~32.2 g,相对误差25%~54%。

The net content of shrimp is an important quality indicator of frozen food, as it is closely related to consumer interest. In this paper, a method of detecting net content of block frozen shrimp was studied, which based on X-ray imaging. According to analysis of gray mean value differences between X-ray images of block frozen shrimp that come from the same mould, with the same thickness but different net content. Result found that in the same imaging parameters state, for the same thickness block frozen shrimp, the gray mean value and net content of shrimp in a linear relationship. The thicknesses of block frozen shrimp are 30 mm, 35 mm, 40 mm, and 45 mm respectively, as four groups. Every group produces a linear relationship between gray mean value and net content of shrimp, the correlation R2 are 0.9958, 0.9983, 0.9897, and 0.9437 respectively. Through testing 20 block frozen shrimps with different thickness and net content of shrimp for verification, the absolute error is 0.03~36.5 g, relative error is below 15% when the solid content is more than 100 g and the absolute error is 7~32.2 g, relative error is 25%~54% when the solid content is less than 100 g, which provides a theoretical basis for reference for the industrial detection of block frozen shrimp and other similar objects.