An Innovative Strategy to Enhance Polyphenol Content and Quality Traits of Olive Oil and Valorization of Mill Wastewater

Olive oil polyphenols are a valuable help for human health and producing high-quality extra virgin olive oil rich in these polyphenols is a key objective for many farmers. In this work, we evaluated the impact of addition of salts to the milling process to increase the polyphenolic content of olive oil. The procedure proved successful, with efficacy dependent on the specific salt used and its concentration. The use of salts, in both laboratory and industrial settings, has increased not only the polyphenol content within the oil but also the yield and the qualitative–quantitative, sensory and nutritional characteristics of olive oil by impacting the amount of other minor constituents of olive oil, such as volatile compounds, chlorophyll, and carotenoids. Using the same approach, and by utilizing wastewater as a source of bioactives, we also successfully enriched other seed oils with olive oil polyphenols minimizing the waste of these substances and valorizing them. This enabled us to obtain a new class of seed oils enriched in antioxidant and anti-inflammatory compounds, potentially representing a new frontier in nutraceuticals.