Environment

Circular economy from olive oil production wastes

Circular economy from olive oil production wastes
  • PublishedNovember 16, 2022

The olive oil industry generates large amounts of solid and liquid wastes, olive pomace and olive mill wastewater being the main ones. All of them have a high load of lipids, organic acids, and phenolic compounds.

One of the main approaches for the valorization of these residues is the extraction of valuable phytochemical compounds, such as polyphenols, with interesting properties for the pharmaceutical, cosmetic, and food industries.

Olive pomace and olive mill wastewater are produced as by-products, regardless of the processing scheme followed.

Olive pomace is a semi-solid waste, composed of olive skin, pulp, and bone. The main components are polysaccharides, proteins, fatty acids, pigments, and polyphenols, and thus it is considered a source of compounds with antioxidant activity. Olive pomace is rich in hydroxytyrosol but also has a significant content in oleuropein, tyrosol, caffeic acid, p-coumaric acid, vanillic acid, verbascoside, elenolic acid, catechol, and rutin.

Olive mill wastewater is the liquid residue composed by the olive washing waters, olive pulp water, water added to olive paste in the centrifugation step of the three-phase scheme, and water from the washing of extraction plants. This waste is constituted by sugars, polyalcohols, lipids, pectins, polyphenols, etc. The main phenolic compound is hydroxytyrosol but also is rich in tyrosol, oleuropein, caffeic acid, vanillic acid, gallic acid, luteolin, and verbacoside, among others.

Research into the application of olive by-products and/or their bioactive compounds is growing, aimed to improve the nutritional profile of food products, to improve food properties, to obtain innovative natural additives for cosmetics, etc.

As stated previously, hydroxytyrosol is widely present in olive oil by-products, and its antioxidant and antimicrobial properties have been widely demonstrated.

The food industry is interested in adding natural antioxidants to packaging materials to preserve food products and extend their shelf-life, while maintaining the organoleptic properties. In this sense, the food packaging sector is developing active materials based, for instance, on by-products of agribusiness, such as lignocellulosic fibers from olive pomace.

The growing number of wastes from the olive oil lead to the necessity to reuse these waste materials and develop further processing technologies, following circular economy schemes, for their beneficial application. Furthermore, the high costs of waste disposal make necessary its recovery, especially for these industries, which use large-scale production processes. Thus, the recovery of polyphenols that are high added-value compounds from these wastes is both industrially sustainable and environmentally friendly. For that, there exist innovative methodologies to analyze, extract, separate, and purify these bioactive compounds with promising results.

Italia Olivicola
Written By
Olivae News