Proteins and peptides are cosmetically active ingredients used in cosmetic products. Due to their properties, as well as a barrier function of the skin, proteins and peptides exhibit limited passage into and through the skin. Whey, a by-product of cheese processing, has been treated as a waste by the dairy industry. Advances in science and technology, legislative regulation, ecological aspects such as »zero waste«, and a greater understanding of whey composition have led to the discovery of its potential use in cosmetics - whey has an effect on the formulation itself while exhibiting positive effects on the skin and hair. Successful incorporation of whey, and of proteins in general, in cosmetics requires the development of an appropriate technological process, that has a crucial affect on the stability of the final formulation.
In our experiment, we developed two formulations with whey; hair shampoo and facial cleansing gel. We used whey in two different forms; liquid (20 % w/w) and dried (2 % w/w), each further in three different fractions; acid whey, filtered whey (permeate), and effluent whey (whey after application to a chromatographic column). First we had to determine the optimum concentration of whey incorporated into the product and adjust the amount of individual ingridients (NaCl, surfactant) to ensure adequate viscosity of a product. We were also interested in how whey affects the properties and stability of the formulation, so we performed preliminary stability tests. For shampoos, half of the samples were exposed to room temperature (25° C) and the rest to elevated temperature (40° C). The gels were subjected to cyclic stability tests, exposing the products to different temperatures every 24 hours (5° C, 25° C, 40° C). As part of the physico-chemical evaluation, important parameters (pH, viscosity and organoleptic properties) were determined. After six weeks of stability study, we found that whey had the greatest influence on the organoleptic properties. Its odor was present. We also observed staining, which increased with increasing whey concentration. The effect of whey on pH was not significant. Whey had no effect on the rheological properties in gels while it increased the viscosity of the shampoos. In addition, dried whey had a greater effect on the viscosity increase than liquid whey. Hair shampoos and facial cleansing gels were classified as stable cosmetic products based on performed preliminary tests. It can be concluded that the use of raw whey and whey protein in cosmetics has great potential, in line with a modern »zero waste« mindset.