Department of Pharmacy Practice, College of Pharmacy and Pharmaceutical Sciences, University of Toledo, Toledo, OH, 43614, USA.
Department of Chemical Engineering, College of Engineering, University of Toledo, Toledo, OH, 43606, USA.
Int J Cosmet Sci. 2021 Feb;43(1):11-19. doi: 10.1111/ics.12661. Epub 2020 Oct 2.
Product aesthetics and sensory performance can strongly influence a cosmetic product's acceptance by consumers. However, classic sensory analysis is time-consuming, expensive and does not provide information on the target group's preference. In the previous phase of this project, we had untrained consumers evaluate six cosmetic emulsions based on their aesthetics using a check-all-that-apply (CATA) survey. In this project, our goals were to quantitatively characterize the rheology and textural properties of the six cosmetic emulsions containing green, bio-derived emollients and identify statistical relationships between the consumers' description of products and the instrumental measurements.
Six emulsions were prepared-three with olive oil and three with heptyl undecylenate as an emollient. Four sensory-like attributes, namely firmness, work of shear, stickiness and adhesiveness, were tested using a texture analyser. Rheological characterization included continuous flow testing and oscillatory measurements. Droplet size and stability were also evaluated. Statistical relationships were quantified between measurements in this study and sensory survey results published previously.
The textural and rheological results indicated that the emulsions were different-as designed. The texture and rheology measurements had analogous grouping outcomes to the consumers' discrimination. Emulsions 1 and 2 were the firmest, hardest to spread, stickiest and had the highest viscosity, while Emulsions 5 and 6 were the least firm, easiest to spread, less sticky than Emulsions 1 and 2, and had the lowest viscosity. Emulsions 3 and 4 fell in between the other two groups. Using olive oil instead of heptyl undecylenate as an emollient increased firmness, spreading, stickiness, viscosity and droplet size of the emulsions in every case-when comparing emulsions within each pair. All six emulsions had a shear-thinning behaviour. Viscosity and firmness directly correlated for the emulsions. Emulsions were visually stable at room temperature over the course of 6 months and viscosity remained relatively constant over this period also.
Certain sensory attributes can be reliably predicted with instrumental measurements. Identifying and quantifying sensory-texture-rheology relationships can contribute to achieving appropriate product characteristics tailored to suit market needs.
产品的美感和感官性能可以极大地影响消费者对化妆品的接受程度。然而，经典的感官分析既耗时、昂贵，又无法提供目标群体偏好的信息。在该项目的前一阶段，我们让未经培训的消费者使用全选（CATA）调查，根据他们对美学的看法对六种化妆品乳液进行评估。在本项目中，我们的目标是定量描述六种含有绿色、生物衍生润肤剂的化妆品乳液的流变学和质地特性，并确定消费者对产品的描述与仪器测量之间的统计关系。
制备了 6 种乳液-3 种含有橄榄油，3 种含有庚基十一烯酸作为润肤剂。使用质构仪测试了 4 种类似感官的属性，即硬度、剪切功、粘性和粘性。流变学特性包括连续流动测试和振荡测量。还评估了液滴大小和稳定性。在本研究中对测量值与先前发表的感官调查结果之间的定量关系进行了量化。
质地和流变学结果表明，乳液是不同的-如设计的那样。纹理和流变学测量结果与消费者的区分具有类似的分组结果。乳液 1 和 2 最硬、最难涂抹、最粘，粘度最高，而乳液 5 和 6 则最不硬、最容易涂抹、比乳液 1 和 2 粘性小，粘度最低。乳液 3 和 4 则介于另外两组之间。在每种情况下，与每个乳液对中的其他乳液相比，用橄榄油代替庚基十一烯酸作为润肤剂会增加乳液的硬度、涂抹性、粘性、粘度和液滴尺寸。所有六种乳液都表现出剪切稀化行为。在这些乳液中，粘度和硬度直接相关。在室温下，所有乳液在 6 个月的时间内都具有视觉稳定性，并且在此期间粘度也保持相对稳定。
某些感官属性可以通过仪器测量可靠地预测。识别和量化感官-质地-流变关系有助于实现适合市场需求的适当产品特性。
