Improving the extraction of carotenoids from tomato waste by application of ultrasound under pressure

• Manosonication improves carotenoid extraction yield from dry tomato pomace.
• Manosonication increased extraction yield around 1.5 times compared to the control.
• Manosonication permits to decrease the hexane percentage in a mixture hexane/ethanol.
• Manosonication does not cause degradation of carotenoid extracts.

The influence of the application of moderate pressure on the ultrasound assisted extraction of carotenoids from dry tomato pomace using a mixing of hexane/ethanol as solvent was investigated. Carotenoid extraction yield (CEY) increased by application of ultrasound and it was higher when static pressure was increased. In previous experiments it was establish that the optimum ultrasound amplitude, static pressure and sonication time for carotenoid extraction were 94 μm of amplitude, 50 kPa, 6 min. These treatment conditions increased the extraction yield 143% in comparison with the control. Response surface methodology was used for optimization extraction temperature (25–45 °C) and the proportion of hexane in the solvent (25%, 50%, 75%) for manosonication assisted extraction of carotenoids. The increment of CEY, the possibility of decreasing the percentage of hexane and the fact that the treatment did not cause degradation of carotenoid extracts are key benefits of manosonication assisted extraction of carotenoids from tomato.