Polyphenols and processing degree of food (NOVA system): Determining the association in a university menu

The amount of natural polyphenols can change according to the processing degree of foods, since part of food containing these compounds can be removed in this process. The aim of this study was to assess the amount of polyphenols according to the processing degree of food. We analyzed the menus of the university restaurant over a period of 87 days and estimated the amount of polyphenols consumed as well as the food processing degree using the Phenol-Explorer database, according to the NOVA classification. Data were assessed using Pearson's correlation coefficient (p < 0.05) and principal component analysis. In the omnivorous menu, a correlation coefficient of 0.5 was observed between total polyphenols and fresh/minimally processed foods. In the vegetarian menu, a correlation of 0.7 was found between flavonoids and ultraprocessed foods. Analyzing the principal components, it was possible to observe that the days containing reduced polyphenols content in the offered menu are those that contained processed and/or ultraprocessed foods. Besides in the vegetarian menu, the days on which the greatest amount of processed foods was offered are those on which textured soy protein (ultraprocessed food) was present, an important source of flavonoids. In conclusion, polyphenols content is affected by the food processing degree.