Recently, people are becoming more and more aware of the importance of protecting the environment and managing waste wisely, which is evident in all areas of life. In the cosmetics sector, products based on a “zero waste” philosophy are becoming increasingly popular, and consumers are willing to pay more for products that contain a higher proportion of natural or biological ingredients. A very good example is the use of whey which was considered a waste product of the dairy industry for many years but is now used in many different areas. In cosmetic science it is a valuable ingredient and represents the source of proteins and has beneficial effects on the skin and hair as well as influencing the properties of the formulation. Likewise, whey, the use of nisin – a natural preservative – has spread from the food industry to other areas, including cosmetic science.
In the thesis we developed three formulations with whey and nisin, which are the following: a hair shampoo, an aromatic water and a nourishing lotion. We used liquid acid whey and liquid nisin and prepared 6 different recipes for each cosmetic product. We were interested in how whey and nisin affect the produced formulations and what their influence on the stability of these formulations is. For this purpose, all products were evaluated for stability by observing organoleptic changes, pH measurements and microbiological challenge tests. In addition to the cosmetic products produced we also evaluated whey and nisin as input ingredients. All products were pre-inoculated with a suspension of Escherichia coli cells as the focus was on microbiological evaluation. We have found that whey has a marked effect on the organoleptic properties of the products. At the end of the tests the whey products had a strong unpleasant odour, a slight yellow colour and visible instability. The effect of nisin and whey on the pH was only significant in the case of aromatic waters, where the pH of the products increased slightly. In the microbiological field, products containing whey and nisin proved to be unstable compared to products containing EDTA in addition to nisin. These products proved to be the most stable in all areas of stability which is attributed to the antimicrobial efficacy of nisin in combination with the EDTA chelator. Based on the results obtained it can be concluded that the use of whey and nisin (in combination with excipients) in cosmetic science is possible and desirable and thus represents a good example of modern trends aimed towards protecting the environment.
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