Proteins and peptides are an important group of cosmetically active ingredients. Their effects on the skin are diverse, ranging from moisturising, antimicrobial protection and mimicking the action of naturally occurring skin proteins, in particular collagen and elastin. One of the raw materials with an important protein content is whey, which was long considered to be a waste by-product of the processing of milk into cheese, but is nowadays used to great advantage in various industries. In cosmetic formulations, most commonly in shampoos, conditioners, cleansing lotions and gels, it is used to stabilise emulsions and foams, to form films, to bind water and as a gel-forming agent. Whey should be highlighted as a source of cosmetically active ingredients for skin and hair or scalp care due to its rich content of proteins such as β-lactoglobulin, α-lactalbumin, immunoglobulin and many others.
In the diploma thesis, we developed and optimised two cosmetic formulations with incorporated whey, namely hydrogels for facial cleansing, which differed according to the type of thickener used, i.e. xanthan or carbomer. In the initial phase of development, the optimum concentrations of xanthan and carbomer were determined and the corresponding amount of decyl glucoside, which acts as a surfactant, was adjusted accordingly. The next stage was to determine the appropriate proportion of whey, with the aim of incorporating as much whey as possible without adversely affecting the physico-chemical and organoleptic properties of the formulations.
In the last part of the task, three selected hydrogel formulations (30 % whey, 1,5 % xanthan, 10 % decyl glucoside) were prepared; 15 % whey, 1 % carbomer, 10 % decyl glucoside; and 30 % whey, 1 % carbomer, 10 % decyl glucoside), which met the criteria of organoleptic properties, viscosity and pH value, were subjected to a stability study, which involved testing samples stored at room temperature (25 °C) and at elevated temperature (40 °C). At predetermined time points, the viscosity, pH and organoleptic properties of the tested samples were evaluated. In the 42-day stability study, whey was found to have the greatest influence on the organoleptic properties of the products, i.e. colour and odour changes. It can be concluded that all three samples with whey are chemically stable (pH, organoleptic properties), irrespective of the type of polymer as thickener. The results should be further developed in the context of long-term stability studies and represent a good starting point for the development of quality cosmetic products based on whey.
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