Evaluation of the storage life of vacuum packaged Australian beef

To establish the shelf-life of vacuum packaged Australian beef, 15 Strip-loins and 15 Cube-rolls for each Processor (A, B, and C) were evaluated at two week intervals (since wk 10 to 20). Steaks on the trays were placed in retail cabinets at 3 °C. Shelf-life evaluation was based on off-odor (only at week 10), microbial analysis, lipid oxidation, and color assessment by trained panelist and Hunter colorimeter. Panelists detected "slightly off-odor" in both primal cuts for Processors B and C (P<0.05). Processor A primal cut steaks displayed better color scores as well as CIE L*, a*, b*, Chroma and Hue values during storage and display period than steaks from the other processors. Also, primal cuts from Processor A showed lower microbial counts and TBARS values with respect to other processors during the trial. Processor A cuts showed improved shelf life attributes initially which helps to explain its slow shelf-life deterioration.     

Variation of pyranoanthocyanins in red wines of different varieties and vintages and the impact of pinotin A addition on their color parameters

The present study evaluates the influence of pyranoanthocyanins on the color of German red wines (Dornfelder, Cabernet Sauvignon, and Pinot Noir) from different vintages from 1996 to 2006. The wines were spiked with a solution of pinotin A raising the natural pyranoanthocyanin concentration in the wine by 2, 5, 8, 10, and 15 mg/L. The color parameters were determined by spectroscopy and the spiked wines were presented to a sensory panel in a 3-alternative forced choice (3-AFC) test for color evaluation. The comparison of treated and untreated wines clearly demonstrated that the influence of pinotin A on the overall perceived color in these red wines was not significant. The 3-AFC test showed no significant difference between Dornfelder and Cabernet Sauvignon wines, due to the increase of pinotin A. Solely in the case of some aged Pinot Noir wines small effects (i.e., strong decrease of lightness and low decrease of chromaticity) were apparent, which could be shown to be due to the dilution of the sample caused by the added pinotin A solution.     

我国多产区干红葡萄酒颜色相关指标的关联分析

采集我国多个产区不同年份的21款干红葡萄酒产品,分析总酚、单宁、颜色参数等感官理化指标,采用相关分析(RA)和主成分分析(PCA)寻找多个感官理化指标之间的联系,挖掘对葡萄酒产品差异贡献显著的重要理化指标。结果表明:供试酒样的颜色深度与总酚、酒石酸酯、黄烷醇和总花色苷的含量显著相关,而与Lab色彩空间(CIELab)参数中的a*负相关;CIELab颜色参数中,L*、b*与花色苷含量显著相关,而花色苷与颜色色调显著负相关;不同品种和不同年份的葡萄酒样品在颜色相关指标的主成分图上分布差异明显。     

基于CIELab颜色空间和颜色分布信息熵的图像检索

针对基于颜色空间信息熵的图像检索,提出了一种新的改进方案,使对颜色特征的提取建立在CIELab颜色空间的基础之上。利用CIELab的均匀颜色空间特性,来完成对颜色空间的分割,使之更符合人眼的色彩感觉特性,得到符合人眼色彩感觉的颜色空间信息熵。在图像相似性度量方面,提出了加权颜色统计函数的比较方法。经实验表明,该算法能够获得比较满意的效果。     

Prediction of red and rosé wine CIELab parameters from simple absorbance measurements

Multiple and simple regression analyses were applied in order to establish mathematical models that allow the evaluation of CIELab parameters from absorbance values at 420, 520 and 620 nm or from Glories parameters, which are better known and easier to calculate. All these variables were measured in 267 commercial wines (141 red and 126 rosé wines). Good mathematical models of the CIELab parameters with small standard errors of estimation were obtained, using the absorbance value at 520 nm, colour intensity or tonality of Glories as an independent variable, with the exception of the b* parameter in the red wines. These models could be helpful to wineries that, in general, do not have the necessary equipment and software to determine the CIELab parameters, which are recognised as being the best parameters for defining the colour of wines. © 2002 Society of Chemical Industry     

Fading of Cotton Yarn Colored with C. I. Vat Blue I (Indigo Dye) via Ozone Application

In this experimental study, the possibility of obtaining of fading effect to indigo dyed denim yarns via ozonation process was searched. Therefore, a novel approach was attempted for fading the denim materials in the form of yarn before weaving or garment processes. The effect of the ozone gas on the CIELab values of indigo dyed yarn specimens was statistically investigated depending on some physical properties of the yarns and application parameters of ozone gas. In addition, the effect of ozone gas on the strength performance of the yarns was investigated. The results showed that different yarn and ozone application parameters affected the fading results. Besides, the ozonation process did not have a crucial negative effect on yarn strength.     

3D Master Toothguide according to L*, C*, and h* coordinates

The purposes of this study are to describe the color coordinates of the 26 shade tabs of the 3D Master Toothguide according to their L*, C*, h* coordinates, and to calculate ΔE_ab*, ΔL*, ΔC*, and Δh* in the 26 shade tabs. The tooth color of 1361 maxillary central incisors was measured “in vivo” using a spectrophotometer. Tooth color was recorded following the 3D Master system and its corresponding L*, C*, h*color coordinates. Of the 325 shade tabs pairs compared a color difference ( ) of between 2.6 and 5.5 units was found in 9.54% (31 pairs). In 291 pairs (89.54%) there was color difference that exceeded the 5.5 units. Only 0.92% of the color differences () were less than 2.6 units. The minimum color difference ( ) found was 2.1 units and the maximum 45.0 units. The intervals in lightness, chroma, and hue groups between adjacent shade tabs were not uniform. In conclusion, this toothguide is clearly ordered regarding lightness or the L* coordinate. Most of the color differences between the 26 shade tabs of the 3D Master exceed the perceptible threshold of 2.6 units. Some clinical implications are as follows: the 26 shade tabs of the 3D Master Toothguide offer improvements as far as spatial arrangement is concerned. Thus, it is highly possible that the subjective visual color of the measurement would be correct. If there is a mistake when choosing the shade tab from the 3D Master guide there will quite probably be an unacceptable color difference from the clinical point of view. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 518–524, 2015.     

纬全显色提花织物的混配色算法研究

为了使用Kubelka-Munk双常数理论求出纬全显色提花织物的单纱表面比例和预测织物颜色,首先使用最小二乘法计算单纱的吸收系数K和散射系数S.采用红、黄、蓝、绿4种颜色为纬纱,按两组分不同比例混合交织得到单经双纬的纬全显色提花织物试样并对其颜色进行测量,求出K值和S值后,得到纬全显色提花织物的配色算法、并对织物中各纬纱颜色的表面比例进行预测.在所测试的60个试样进行颜色匹配,色差约为1.5个CIELab单位,对于拟合得到的单纱比例误差也在2.1％左右,表明该模型可以较好地解释纬全显色提花织物颜色与各单纱颜色比例之间的关系.     

贺兰山东麓年轻红葡萄酒的CIELab颜色空间特征

采用CIELab系统方法得到宁夏贺兰山东麓年轻红葡萄酒的颜色空间参数,并研究花色苷与颜色参数的相关性。以贺兰山东麓产区2012年份不同品种的10 个年轻红葡萄酒为材料,采用紫外分光光度计和pH示差法计算得出CIELab颜色空间参数以及总花色苷含量,通过相关性分析对葡萄酒各个颜色参数和总花色苷进行研究。结果表明：不同葡萄酒样品的明度L*、红度a*、黄度b*、饱和度Cab和色调角Hab等空间参数不同,表现出不同的颜色特征;总花色苷含量在161.2～287.8 mg/L,与参数L*、a*、Cab均呈显著相关性,决定年轻红葡萄酒的明度、色度及饱和度。