Extraction and microencapsulation of bioactive compounds from olive oil processing solid wastes

Mestrado em Engenharia Alimentar - Instituto Superior de AgronomiaThe food industry by-products such as olive oil processing solid waste are an important source of natural bioactive compounds. The aim of the present work was to extract bioactive compounds from olive pomace using supercritical carbon dioxide extraction and to investigate the viability of their encapsulation in a food-stuff carrier as a way of protection from antioxidant properties losses. Several supercritical extractions were performed at a 250 bar and a 40 ºC with and without pre-treatments and levels of moisture content were also tested. Yields between 8 and 12% (w/w) were achieved and fatty acid content, sterols and total poliphenolic compounds were evaluated in all supercritical extracts. Since there are a strong correlation between antioxidant activity and poliphenolic compounds, the two most representative phenols, hydroxytyrosol and tyrosol, were identified and quantified. Antioxidant activity was also investigated using ORAC and HORAC methods. Extraction of bioactive compounds from olive pomace in soxhlet apparatus were also carried out for control and yields of 13% (w/w) were achieved. Encapsulation of the most bioactive extract achieved was performed by spray-drying using inulin as the wall material and antioxidant activity was evaluated