高水分挤压组织化蛋白纤维取向度光学评价方法研究

Characterization of Fiber Orientation Degree in High-Moisture Extruded Textured Protein by Using Optics Method

高水分挤压组织化蛋白是传统膨化型组织化蛋白的升级替代产品,纤维取向度是衡量其类肉程度的重要指标之一。蛋白原料经高水分挤压得到组织化蛋白,然后通过数码相机采集激光反射图像、自编Matlab程序对图像进行定量分析,考察了图像获取参数(曝光时间、光源入射角、拍摄背景)、样品参数(样品厚度、样品含水率)和图像处理参数(拟合椭圆位置)对纤维取向度分析结果的影响。结果表明:当相机曝光时间1/50 s、光源入射角75°、样品厚度2 mm、样品挤出到图像采集的时间间隔0 h、黑色拍摄背景、拟合椭圆的选择位置位于椭圆短轴长度大于400像素的范围时,挤压组织化蛋白纤维取向度的分析结果比较理想。验证试验证明,所建立的光学评价方法可以完全区分纤维取向度不同的挤压组织化蛋白产品。

High -moisture extruded textured protein is the higher substitute for traditional expanded typed tex- tured protein. Degree of fiber orientation is one of the important indexes for evaluating the similarity of meat analogue. The laser reflection images of textured sample extruded at high - moisture level were captured by digital camera. The quantitative analysis for the obtained image was implemented by self - compiled computer program with the help of Matlab software. In this paper, the effects of the parameters of image acquisition （ i. e. exposure time, incident angle of light source, background shooting）, the parameters of samples （i. e. thickness, moisture content） and the parameters of image process （i. e. selected position of ellipse fitting） on the analysis results for degree of fiber orientation were optimized systematically. The results showed that on the condition of exposure time 1/50 s, incident angle of light source 75°, sample thickness 2 mm, time interval from extrusion to image acquisition 0 h, background shooting black and the position of ellipse fitting selected within the range of short axis for ellipse greater than 400 pixels, the analysis results were relative ideal for the degree of fiber orientation. Verification test indicated that the established optic evalu- ating method could differentiate completely textured protein products having difference in degree of fiber orientation.