A multidisciplinary approach in the study of tocosh flour (Solanum tuberosum L.) for potential dermocosmetic applications

In Latin American tradition, food fermentation represented an efficient strategy to preserve native crops and maintain adequate survival stocks. In particular, potato tocosh is an ancestral fermented flour still prepared in small communities from the highlands of Central Peruvian Andes. After 6-9 months of fermentation, the product is kept for consumption as a sun-dried and ground fine flour-type product with nutritional and curative properties. It is considered an effective and low-cost antibiotic (“the natural penicillin of the Andes”), energizer, and probiotic product, useful for several diseases, hair, and skin care. Lactobacilli seem to be the responsible for fermentation, notable medicinal properties, and distinctive odour. Its chemical composition discloses the presence of carbohydrates (mainly starch, 80%), proteins (3.9%), alkaloids, free amino acids, minerals, thiamine, and riboflavin, among other vitamins. Nonetheless, the product emits a pronounced rotten odour, likely attributable to the presence of free carboxylic acids, probably produced during the fermentation process. The aim of this research was to investigate tocosh as a new potential pharmaceutical and cosmetic multifunctional ingredient with rheological, antioxidant, and preservation properties. With this purpose, the product was analysed and characterized, with particular regard to the volatile fraction (responsible for the odour), by GC-MS analysis, the amylose content, gelling behaviour (in comparison to potato starch), total phenolic amount, radical scavenging activity and antimicrobial properties. Furthermore, to enhance the suitability of the product for dermocosmetic applications, a simple preliminary treatment was attempted to neutralize its stinky odour, by exploiting Fischer esterification.