Deriving valorization of phenolic compounds from olive oil by-products for food applications through microencapsulation approaches: a comprehensive review

Abstract

Nowadays, olive oil consumption is correlated to many health benefits, essentially due to the presence of antioxidants, especially phenolic compounds, which fostered its intensive production worldwide. During olive oil extraction, through continuous or discontinuous processes, many olive oil by-products are generated. These by-products constitute an environmental problem regarding its management and disposal. They are phytotoxic and biotoxic due to their high content of phenolic compounds, presenting contrastingly relevant health benefits due to their potent radical scavenging activities. In the framework of the disposal and management of olive oil by-products, treatment, and valorization approaches are found. As currently, the majority of the valorization techniques applied have a null market value, alternative strategies for the obtainment of innovative products as fortified foods are being investigated. The recovery and valorization strategies of olive oil by-products may comprise extraction and further encapsulation of bioactive compounds, as an innovative valorization blueprint of phenolic compounds present in these by-products. The majority of phenolic compounds present in olive oil by-products possess limited application on the food industry since they are promptly amended by environmental factors like temperature, pH, and light. Consequently, they must be protected previously ending in the final formulation. Prior to foods fortification with phenolic-rich extracts obtained from olive oil by-products, they should be protected through microencapsulation approaches, allowing a sustained release of phenolic compounds in the fortified foods, without losing their physicochemical properties. The combined strategies of extraction and microencapsulation will contribute to promoting the sustainability of the olive oil sector and aid the food industry to obtain reinvented added-value products.

Keywords:

• Olive oil by-products
• olive pomace
• olive oil wastewaters
• olive leaves
• microencapsulation
• phenolic compounds
• extraction
• valorization

Disclosure statement

Authors declare no conflict of interest or any financial benefit from direct or indirect applications of the research.

Additional information

Funding

This work was financially supported by projects UID/EQU/00511/2019–Laboratory for Process Engineering, Environment, Biotechnology and Energy–LEPABE funded by national funds through FCT/MCTES (PIDDAC) and the project “LEPABE-2-ECO-INNOVATION”–NORTE‐01‐0145‐FEDER‐000005, funded by Norte Portugal Regional Operational Program (NORTE 2020), under PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This work was developed under the doctoral program in Chemical and Biological Engineering (PDEQB) NORTE-08-5369-FSE-000028, co-financed by the Northern Regional Operational Program (NORTE 2020) through Portugal 2020 and the European Social Fund (ESF).