Pearlized shampoo and sensory analysis : link appearance of EGDS crystal to analytical methods

Measuring the peariescent quality of shampoos by eye is a complex and rigorous task. A quick estimation of the time spent to visually classify research samples is approximately 50% of the development time. However correct classification of the pearlescent quality/appearance is essential since the function of the cold pearl products is to provide a visual benefit. Typical pearlizing products include ethylene glycol distearate and ethylene glycol monostearate. Altering the processing procedures, chemical formulations, or quality of the pearlizing agent can create different crystal morphologies and different pearlescent appearances. Based on visual analysis we can look at three critical parameters to describe the basic appearance of pearlized shampoos. The complexity of the visual assessment is seen in the interdependency of each measurement on the others. Additionally, the sample characteristics, the method of application, and the observation technique can have an effect on the visual results. An accurate and efficient analytical method to correctly classify pearlescence would save time and eliminate inconsistencies between different researchers. By understanding the effect of light on the pearlized product, we were able to find the appropriate instrumentation and method to measure the pearl appearance.