SAPPAN (Caesalpinia sappanL.) EXTRACT-BASED LABEL FOR DETECTION OF CHICKEN MEAT SPOILAGE

Brazilin in sappan is sensitive to pH, which make it possible as indicator of food quality. This research aimed to investigate performance of sappan extract as colorant for indicator label applied in chicken meat packaging. The samples were stored at room and refrigerator temperature. They were then tested for color change of label RGB (Red Green Blue), pH and TVB-N (Total Volatile Base-Nitrogen) of the meat. Data were analyzed using ANOVA at significant level of 5%. Indicator label showed the reduced RGB during storage, while pH and TVB-N increased. In case of room temperature, the color change into pink occurred in day 3 with pH 6.72 and TVB-N 1.84 mg N/100g. Meanwhile, for samples at refrigerator temperature, the label color turned into pink in day 6, with pH 6.56 and TVB-N 2.09 mg N/100g. In this regard, indicator label could detect the depletion of chicken meat quality as indicated by color shift from yellow to pink when pH and TVB-N were at critical value. This result provides significant output for development of sappan extract for indicator of meat spoilage.

Comparison the effect of charcoal-containing, hydrogen peroxide-containing, and abrasive whitening toothpastes on color stability of a resin composite; an in vitro study

Background This study aimed to compare the effects of charcoal-containing, hydrogen peroxide-containing, and abrasive whitening toothpastes on color stability of a resin composite. Methods Forty-five specimens were fabricated of spectrum TPH3 composite resin and stored in artificial saliva for 24 h. Baseline color assessment was performed using a spectrophotometer device. Then, the specimens were randomly assigned into 5 experimental groups, namely distilled water (GC), Bencer (GB), colgate optic white (GO), perfect white black (GP) and colgate total whitening (GT) toothpastes. The specimens immersed in coffee solution for 10 min and brushed for 1 min with respective toothpaste and then stored in artificial saliva until the next day. This cycle was repeated for 30 days. After 30 days, the final color assessment was performed using the spectrophotometer. Data were analyzed using one-way ANOVA and Tukey tests. Results Experimental groups were not significantly different in terms of Δa and ΔE values. However, ΔL and Δb values showed significant difference among the groups. Regarding Δa, GT and GC groups showed red color shift while the other groups showed green color shift. Regarding Δb, all groups showed blue color shift except GT group which showed yellow color shift. Conclusion None of the whitening toothpastes could decrease discoloration caused by the coffee solution to the level below the perceptibility threshold except Colgate Optic White which reduced discoloration within the clinically acceptable perceptibility range.

The threshold of color inconstancy

Color inconstancy refers to significant changes in the perceived color of an object across two or more different lighting conditions, such as daylight and incandescent light. This research focusses on defining the threshold of color inconstancy between generated D65 and A illumination through a psychophysical experiment. Although modern color appearance models provide equations to calculate the degree of adaptation, a neutral grey match experiment was completed to produce a more accurate D values for the experimental viewing conditions. Like setting an instrumental color tolerance experiment, a second, sorting, experiment was used to define the threshold of color inconstancy. This threshold is the color shift, expressed in color difference terms, required for observers to notice a color change across changes in illumination. In addition, the tolerance ellipsoid for each Munsell principal hue group was also established.