Lycopene-rich avocado oil obtained by simultaneous supercritical extraction from avocado pulp and tomato pomace

Abstract

Tomato pomace is a residue of tomato processing which contains lycopene and oil, and is generated in large quantities by the tomato processing industry. Raw avocado oil is a special oil similar to olive oil. In order to combine the advantage of using a clean technology with supercritical carbon dioxide (scCO2) to extract avocado oil and use it as a co-solvent with scCO2 in carotenoid extraction from tomato pomace, simultaneous extractions of oil and lycopene were carried out to produce an avocado oil enriched with lycopene and a semi defatted avocado cake of potential commercial value. Therefore, freeze-dried avocado and tomato pomace were placed separately in the same fixed bed extractor, where lipids and lycopene were simultaneously extracted with scCO2, first passing through the avocado bed and then both scCO2 and the oil extracted from avocado passed through the second bed of tomato pomace. Lipids extracted in the first bed served as a co-solvent with scCO2 for lycopene extraction in the second bed. The experiments were performed using different proportions of the raw materials at 50°C and 400bar and in equal parts of avocado pulp and tomato pomace while varying the temperature and pressure conditions (40, 50 and 60°C; 200, 300 and 400bar). The results showed that the lycopene extraction yields (lycopene recovery) increased as the proportion of avocado increased and the best condition for extraction of lycopene present in tomato pomace was at 400bar and 50°C. The extracts are raw avocado oils enriched with about 110–170μg of lycopene per gram of oil, resulting from up to 80% recovery of oil and lycopene. The resulting avocado cake is a semi-defatted product with potential commercial value.