Mechanically Recovered Neck Bone Lean and Ascorbic Acid Improve Color Stability of Ground Beef Patties

Ground beef patties at two ascorbic acid (Asc) levels (0 and 1,000 ppm) and three mechanically recovered neck bone lean (MRNL) levels (0, 15 and 30%) were analyzed for percentage surface metmyoglobin (metMb) and HunterLab L* and a* values over 6 days of retail display. Data were collected for two replications. Patties made with Asc had less (P < 0.01) surface metMb than patties made without Asc on days 1-4 of retail display. Ascorbic acid and MRNL acted synergistically to improve surface color. Patties made with Asc showed a linear decrease (P < 0.05) in surface metMb as MRNL level increased from 0 to 30%. Patties made without Asc showed no change in surface metMb as MRNL level increased.     

Color of fresh, frozen and cooked ground beef patties manufactured with mechanically recovered neck bone lean

Mechanical systems that recover lean tissue from beef vertebrae without grinding bone material are in use in major packing plants across the country. Our objective was to determine the effects of mechanically recovered neck bone lean (MRNL) on color stability of fresh, frozen and cooked ground beef patties. Ground beef patties at two fat levels (10 and 20%) and four MRNL levels (0, 15, 30 and 45%) were analyzed for percentage surface metmyoglobin (metMb) and HunterLab L^* and a^* values over 12 days of fresh display and 18 weeks of frozen storage. Data were collected for three replications of the experiment. Mechanically recovered neck bone lean caused an increase in surface metMb up to 7 days of retail display; however, patties made with higher levels of MRNL showed a rapid decrease in surface metMb from days 8 to 12. Both the increase and decrease in surface metMb may be due to microbial effects, which were greater at increased levels of MRNL. Patties made with 30 and 45% MRNL showed greater (p < 0.05) surface metMb by 18 weeks of frozen storage than controls; however, patties with 15% MRNL were not different (p > 0.05) than controls. HunterLab L^* values for cooked patties decreased in a linear fashion (p < 0.01, R² = 0.70) as MRNL level increased.     

DETERMINING FAT CONTENT IN GROUND BEEF VIA COLOR IMAGE PROCESSING

Two lots of beef trim were formulated into nine meat blocks which ranged from 9 to 32% fat. Ground samples (n=2) were randomly taken from each meat block, images were captured in the hue, saturation and intensity (HSI) format and fat content were determined. Patties from each block were manufactured and randomly selected (n=3) for image capture and fat content determination. The HSI statistical function characteristics for the color distribution curves were evaluated. Fat content was correlated to many of the image characteristics (p < 0.05). Image variables accounted from 81 to 87% of the variation in actual fat content, depending on which form was analyzed, and residual standard deviations ranged from 2.75 to 3.62%. These data show that image processing may be a useful technology for monitoring ground beef composition with fat levels up to 32%.     

Determination of doneness of beef steaks using fuzzy pattern recognition

The c-means and k-nearest neighbor algorithms of pattern recognition were used as methods of determining the degree of doneness of beef ribeye steaks. For each method, an approach employing the theory of fuzzy sets was used in addition to the traditional crisp approach. Steaks were heat processed to various degrees of doneness. The red, green and blue components of the steak images were acquired using a digital image processing system. Values were then converted to the hue, intensity and saturation. The use of the mean and standard deviation of these six values as features was investigated. The means of the red, intensity and saturation and the standard deviation of the red were found to be of most value as features for the classification techniques investigated.     

Determination of animal skeletal maturity by image processing

Color image features were computed to characterize the skeletal maturity of beef carcasses based on cartilage ossification in the thoracic vertebrae. A trained neural network was tested for predicting USDA beef maturity grades from image features of ossification. A feature curve was defined to characterize the color variations of an isolated cartilage-bone object. Both RGB and HSL color systems were used to derive image features. The maturity grades were assigned by an official USDA grader. Two sets of samples were obtained from two different meat-processing plants. The first set contained samples of only A and B maturity grades whereas the second set had all five maturity classifications (A through E). The hue value was the most useful color feature. The mean hue values of cartilage differed (P<0.05) among the maturity grades and the feature curve based on the hue value was used as neural network input for maturity prediction. The accuracy of prediction was 75% for the first set of samples and 65.9% for the second set of samples. The results data show the potential of computer vision techniques for beef maturity assessment.     

茶树菇水提取液对生牛肉糜抗氧化的研究!

目的:研究新鲜茶树菇子实体水浸提液对生牛肉糜的抗氧化作用。方法:从pH、高铁肌红蛋白含量(metMb)的变化、硫代巴比妥酸反应物值(TBARs)、色泽感官评定四个方面来评价茶树菇水提取物对生牛肉糜的抗氧化效果。结果:在贮存期内,随时间的增加,pH变化不大,TBARs和metMb含量明显降低,颜色变暗被抑制。结论:茶树菇水提取液对生牛肉糜具有一定的抗氧化作用。     

从RGB到HSV色彩空间转换公式的修正

针对从RGB色彩空间到HSV色彩空间的转换方式为非线性变换,会产生奇异点和不稳定点的问题,对转换公式作了修正.原公式在饱和度为零时色度未定义,在低饱和度时色度不稳定,这些情况下色度为黑色、灰色或者白色,将色度分量的低值区域和高值区域分别用来表示黑白色或者偏黑和偏白的低饱和度色.不但能够消除色度奇异点和不稳定点,而且可以用单纯H分量来表述色彩图像的主色调信息,简化了图像计算的复杂度.通过分析和实验验证,方法是有效的.     

鲜食葡萄果穗形状颜色的多视角投影成像检测

设计了一种基于平面镜的低成本多视角投影成像结构,用于获取鲜食葡萄果穗不同侧面信息来判断果穗形状、颜色是否合格。采用两片前表面平面镜来延伸单目相机的拍摄视野,以最大限度地获取果穗全表面信息。通过图像处理方法分割果穗的实像虚像区域,并借助悬挂果穗的高度不变属性对虚像区域进行放大,得到三个每隔120°的同样高度果穗。提取果穗区域、轮廓宽度曲线参数来对果穗外观形状进行评价,与人工分级对比,对果穗形状分级的准确率为95.5%;将彩色图像RGB转换到HSI颜色空间,从色度图像(Hue)获取果穗成熟时的典型颜色区域,计算果面着色面积比例,并按照着色面积比例的大小进行颜色分类,准确率为81.1%。结果表明多视角同时成像的方法可用于葡萄外观的分级,为在线检测提供参考。     

Application of biospeckle laser technique for determining biological phenomena related to beef aging

Among the features of beef quality, color is a major factor that influences marketing since it is the only characteristic consumers can see at the time of purchase, although tenderness is the organoleptic trait that most affects consumer acceptance of beef. Thus, an effective technology to predict meat quality is highly desirable for the meat industry. Among many emerging technologies, optical methods have the greatest potential since they are fast, nondestructive, and generally low cost. This study evaluated the potential application of laser biospeckle technique and its methods of image processing in order to assess and quantify biological phenomena related to beef aging. Samples of muscle Longissimus thoracis were aged for 21 days and underwent biospeckle analysis, objective color and Warner–Bratzler Shear Force (WBSF). According to the results, biospeckle laser parameters may, possibly, assess biological activity resulting from action of endogenous enzymes (calpains and cathepsins) responsible for the aging process through its correlation (R = 0.6146) with analysis of WBSF and of the correlation (−0.7973) with aging time. High correlation of biospeckle analysis, related to traditional out puts and to new proposals, were obtained to color parameters, especially hue angle (h^*) whose R value was 0.7953, redness intensity (R = 0.8120) and percentage of metmyoglobin (MMb) showed that R value of 0.9119, demonstrates the potential of this technique for evaluating quality of meat color.     

棉织物感官色与客观色关系研究

以棉为例，对织物不同组织结构上的客观色和感官色进行测试，并用统计软件进行实验数据分析。探讨织物结构的不同对感官色变化的影响。结果表明：客观色的亮度越高，感官色的亮度也越高；客观色的饱和度越高，感官色的饱和度也越高；饱和度越大，色相差越小；亮度很大或者很小时，色相差很大，否则色相差值很小。这揭示了织物颜色变化引起人眼感受变化的规律与人眼对织物颜色敏感性的判断。     

Extrudate Characterization by Image Processing

Image processing techniques were used to characterize an extruded food product. Several image features in color and surface texture were developed and tested for their effectiveness to reflect changes in product appearance resulting from variations in extrusion conditions. The effects of process variables were related to the image features. Hue function conveyed more information about surface texture than did saturation or intensity functions.     

Composition and Chemistry of Mechanically Recovered Beef Neck-Bone Lean

The objective was to characterize basic chemical and functional differences among mechanically recovered neck-bone lean beef (MRNL), hand-trimmed neck-bone lean beef, a control of 85% beef lean trim and bone marrow. MRNL had higher (P < 0.05) metmyoglobin reducing ability and more total iron than the control and more fat (P < 0.05) than hand trim. Values for pH were higher (P < 0.05) for MRNL than for hand trim or the control (6.68, 6.33 and 5.80, respectively). MRNL also had higher (P < 0.05) nonheme iron, total pigment and water-holding capacity. Bone marrow had higher (P < 0.05) ash, cholesterol, total iron, total pigment and pH than any lean types.     

应用区域颜色分割的机采棉杂质检测方法

机采棉中的杂质繁杂,而杂质类型及含量对后期棉花加工工艺的影响很大。为此,提出一种应用区域颜色分割方法以检测棉花中的杂质。在图像分割中,先对滤波后的机采棉图像进行彩色梯度运算,通过扩展极小变换运算获得标记图像,在修改后的梯度图像上运用分水岭算法获得初始分割图像,然后对初始分割图像进行区域合并。区域合并过程中要综合考虑空间邻接性、颜色信息和区域面积3个因素。颜色信息主要采用饱和度、亮度、区域颜色向量模及颜色相似度4 个特征量。用层次递进的合并方法,迭代过程更新信息特征。最后通过支持向量机算法提取颜色、纹理、形状特征对杂质区域进行识别。结果表明,所提方法对机采棉中天然杂质的平均识别率为94%。     

显色图像分析技术在水稻叶耳花青甙显色目测分级中的应用

目的基于颜色特征的叶耳花青甙显色分级研究。方法以水稻倒二叶叶耳花青甙显色测试为切入点,在Emgu Cv3.0图像分析软件基础上,对完成图像分割的目标区域提取红绿蓝(red green blue, RGB)、色调饱和度亮度(hue saturation value, HSV)颜色特征,利用SPSS软件对颜色特征和测试分级数据进行相关性、回归等统计分析,建立颜色特征多元回归模型。结果叶耳花青甙显色强度与R(红色)、G(绿色)、B(蓝色)、H(色调)、V(亮度)极显著负相关;所有颜色特征值中,G值与叶耳花青甙显色强度相关性最显著,是一元和多元回归主要自变量; G值建立的一元回归模型中, R~2为0.980;多元回归模型R~2值为0.994。结论回归模型的拟合效果好,用这两个模型均可完成叶耳花青甙显色强度分级。     

RELATIONSHIP BETWEEN INSTRUMENTAL AND VISUAL COLOR IN A RAW, FRESH BEEF AND CHICKEN MODEL SYSTEM

A range of meat redness was created by mixing fresh, chilled ground chicken breast and ground beef in predetermined ratios. Samples were scored for visual redness under halogen (incandescent) and cool white fluorescent lighting. Instrumental color characteristics (L*, a*, b*, hue angle, chroma; illuminants A and F) and red color contributed by oxymyoglobin (percentage reflectance at 630 nm versus 580 nm) were determined. Correlation coefficients were determined between visual and instrumental evaluations. The a*, b*, and ΔR (630–580) were highly correlated to visual redness (halogen light: r = 0.99, -0.99, and 0.96, respectively; cool white fluorescent light: 0.98, -0.98, and 0.96, respectively). Regression analysis was conducted to develop equations to predict visual redness using instrumental color measures. In the 20% to 85% beef range, the regression curves were principally linear although the overall relationships (0–100% beef range) were cubic. Among the instrumental color parameters, a*, hue angle, and ΔR (630–580) could be used to predict visual redness for this model system.     

Application of Image Analysis Combined with Computational Expert Approaches for Shrimp Freshness Evaluation

This study was aimed to evaluate the freshness and quality of cultured shrimp (litopenaeus vannamei) during 9 days of storage on ice (i.e., at a temperature of 0°C) using image processing technique. A lighting chamber was used to provide uniform conditions for illumination. The shrimp freshness was evaluated using computer vision technique through color changes of head, legs and tail of the harvested shrimps. Thirty-six color parameters of the images such as mean and variance of red (r), green (g), blue (b), lightness hue (h), saturation (s), value (v), luma information (i and y), the luma component (y), chroma component (cr), lightness (L*), redness (a*), yellowness (b*), chroma (c), and hue (h) were analyzed. Some parameters, such as b*, from side pictures and r mean, b variance, v mean, y mean, b* mean and (L*) mean from top pictures changed with a rather similar trend during the storage period. Different computational expert approaches such as linear discriminant analysis, quadratic discriminant analysis, K nearest neighbors, and discriminant partial least squares regression were examined for shrimp freshness classification. For this, all the variables and the subsets of variables were selected by means of stepwise linear discriminant analysis, stepwise orthogonalization, classification and regression trees. The shrimp freshness was characterized with a high classification accuracy of 90%. Freshness evaluation using image processing is proposed as a potential technique to the food industry.     

EVALUATING EXPANDED-FOOD SENSORY PROPERTIES BY IMAGE ANALYSIS

The objective of this study was to ascertain whether sensory properties of extruded corn puff texture can be predicted by digital image analysis. Gradient image statistics, such as third moment and standard deviation, run-length statistics, and features computed from fuzzy edge-detected image were used. Visually-determined sensory properties included cell density, cell wall thickness, cell size uniformity. Crushing force between molars and biting force between incisors were among the hardness-related sensory properties. All the sensory properties could be predicted with a coefficient of determination (r²) of 0.89 or higher. In most cases, a polynomial function of an image feature was the best model for predicting sensory scores. Image features derived from the intensity band of a hue, saturation, and intensity color model gave the highest r² values for predicting visually-determined sensory properties. For hardness-related sensory properties, the features derived from saturation band resulted in the best r² values.     

A RESEARCH NOTE: EFFECT OF CITRIC ACID AND/OR ROSEMARY EXTRACT ON COLOR OF AN IRRADIATED BEEF MYOGLOBIN MODEL SYSTEM

To determine the effect of antioxidants and irradiation on meat color, myoglobin (Mb) was extracted from beef hearts. Mb was treated with one of four antioxidants (control, citric acid [CA], rosemary extract [RE] or combination of citric acid and rosemary extract [CA/RE]) and irradiated at 0.00 (Control), 0.50, 0.75, 1.00, 1.25, 1.50, 1.75 and 2.00 kGy. Samples were then evaluated for thiobarbituric reactive substances, pH, L*, a* and b* values, hue angles, and Chroma. RE- and CA-containing samples had the highest postirradiation L*, a* and b* values, indicating they were lighter, redder and more yellow than controls. In terms of hue angles, all samples treated with antioxidants were much closer to the true red axis ( a* =  0) of the CIE color space, both before and after irradiation, than was the control . The only color attribute affected by irradiation dose was L* value. Samples irradiated at 2.0 kGy were significantly lighter ( L* =  5.27) than samples that had not been irradiated ( L* =  1.28).

PRACTICAL APPLICATIONS

Irradiation is an effect method for extending the shelf life and improving the safety of fresh meat products; however, it can cause undesirable color changes at the surface of the meat, which appear to be the result of oxidative processes – therefore, reducing oxidation could effectively reduce color change. Studying pigment preservation is difficult in intact muscle tissue, so a myoglobin model system was developed for this purpose. Natural antioxidants were evaluated in this system. Rosemary extract and citric acid maintained color lightness and redness. Surface application of these antioxidants has the potential to preserve red meat color during irradiation.     

基于颜色空间与聚类分析相结合的袜带辨色分级方法

针对丝卷检测中锦纶长丝染色均匀度测定的问题。采用CCD摄像头提取袜套样本图像,提出了应用商图像归一化的方法对袜套图像进行光源空间均匀性校正;应用多项式回归模型对摄像头提取的袜套样本图像进行色度特征化处理,得到的平均和最大色差分别为0.439和1.328 CIELAB色差单位;通过HSV颜色空间的色度百分率直方图,得到待检测袜套的颜色特征值,再由经验方程将其转化为聚类分析的输入矢量,最后应用聚类的方法对全体袜套的特征进行分析,得到袜带的染色分级区间及各段袜套的染色评级。结果表明,取得聚类过程中的参数最大迭代次数为100,终止误差限为1×10-5,模糊加权指数为2,得到聚类中心个数分别取2、3、4、5时的分类结果与人眼视觉比较,误差在0.125%以内,该误差远低于生产技术指标的允许误差,可用于对袜套颜色指标的检测和分级。     

Cooked Color in High pH Beef Patties as Related to Fat Content and Cooking from the Frozen or Thawed State

Beef patties were processed from high pH (>6.0) beef to contain 5, 10, 15, 20 or 25% fat. Patties were cooked to 71°C from the frozen or thawed state before evaluating color. Neither fat content nor state of patties when cooked exerted any major influence on color, but linear effects (p<0.01) in association with increased fat content included higher L* values and hue angles and lower a* values (15.2% reduction). Higher values for L*, b* (but not for 5% fat patties), and hue angles were observed for patties cooked thawed rather than frozen. The use of high pH beef lessened the effects of increased fat and cooking from the thawed state on increased brown color in cooked patties.