A research team from Portugal and Spain has shown that compounds from olive oil waste could be used in cosmetic products.

The results of the study, published in Comprehensive Reviews in Food Science and Safety on 13 November, found that after suitable extraction and purification, these compounds could be used as active ingredients in nutraceutical and cosmetic products and also used as food antioxidants.

With a focus on olive pomace – the main residue of the olive oil extraction process – produced by the two-phase system, the researchers explored the applications of the main individual compounds found in the waste.

The most abundant bioactive compounds in olive pomace are hydroxytyrosol, tyrosol, oleuropein, oleuropein aglycone and verbascoside.

As well as having antioxidant benefits, these compounds also have anti-microbial, anti-cancer, or anti-inflammatory properties, according to the report, making them suitable for use in pharmaceutical and cosmetic products or in food fortification.

Hydroxytyrosol, for example, was already used as an ingredient in different cosmetics, including anti-ageing and lightening/whitening products, the report said.

Earlier studies had also demonstrated hydroxytyrosol’s dermatological properties, for example, to prevent protein damage induced by long-wavelength ultraviolet radiation in melanoma cells or to counteract atopic dermatitis, respectively.

Oleuropein also offers pharmacological benefits, according to the report, due to its strong antioxidant and anti-inflammatory properties.

It had been used as an active ingredient in gels and creams for healing wounds and ulcers in elderly and/or diabetics individuals, the researchers wrote.

In its conclusion, the study said the compounds present in the wastes generated during the olive oil extraction process could have considerable health benefits and could be used, after suitable purification, as food antioxidants or active ingredients in nutraceutical and cosmetic products, due to their recognised technological and pharmaceutical properties.

However, further research was needed in order to evaluate their usage and maintain environmental sustainability, the report said.

“It is imperative for the development of green and efficient extraction methods to ensure higher recovery of these compounds and the cooperation between industry and researchers to generate sustainable added value to these by-products, thus contributing to the circular economy,” the researchers wrote.