Tomato waste anti-oxidation: Researchers tout olive oil solvent as best fit for lycopene extraction

29 Jul 2022 --- Researchers from Hildago, Mexico, studied the extraction of lycopene, an anti-oxidative compound found in tomato waste, to determine the most effective extraction method. They carried out the study by means of agitation and high-intensity ultrasound, using three types of vegetable oils – grape, extra virgin olive and peanut.

Previous studies have uncovered that lycopene is functional in limiting MMP-1 secretion, an enzyme responsible for collagen damage, by approximately 50%. Additionally, it may help restore pro-collagen secretion.

“The primary goal of this current study was to extract lycopene from tomato – Solanum lycopersicum species – and characterize its physicochemical, thermal, antioxidant and viscous characteristics utilizing developing technologies such as high-intensity ultrasound,” the researchers comment.

The extraction of lycopene from organic wastes using agitation and ultrasound was found to be effective, offering an alternative to standard solvents. The best results, however, came from agitated extraction with olive oil.

Potent botanical for shielding cells
Lycopene has multiple therapeutic characteristics and functions as a powerful antioxidant, shielding cells from oxidative damage caused by free radicals, which are responsible for aging, cardiovascular disease, and several forms of cancer – therefore lowering the risk of chronic illnesses.

Tomatoes are herbaceous plants that are grown in greenhouses or in open fields. Mechanical damage, improper transit and storage time can reduce tomato quality dramatically.

Mechanical damage, improper transit and storage time can reduce tomato quality.“It is believed that 10-15% of the overall volume is waste, which is often utilized for compost or animal feed,” highlight the researchers. “However, it is a good source of carotenoids and lycopene.”

To conduct the study, the researchers tested the different oils for their melting temperatures. The thermograms utilized in the investigation revealed that the melting temperatures were lower as the degree of oil unsaturation increased.

Olive oil was the least unsaturated and contained the most oleic fatty acid. Grapeseed oil had the lowest melting temperature, which was about 24.64 C.

Assessing the ideal solvent
Because low toxicity solvents must be utilized, the type of solvent used to extract plant components is critical.

The solvent must be able to absorb and transfer the energy of the ultrasonic wave as well as permeate the material’s core to extract the bioactive chemicals.

“The polarity of the solvent also has an effect on the extraction,” note the scientists. “Previous research has shown that edible vegetable oil has potential as a solvent in the ultrasonic extraction of desired chemicals due to its ease of use and ability to be enriched by carotenoids.”

Several research groups are working on lycopene extraction. However, different strategies are now being studied in order to produce the most ecologically friendly and dependable method of extraction.

Lycopene is a powerful antioxidant that shields skin cells from aging.High-intensity ultrasound not recommended
Due to its generation of free radicals that oxidize lycopene, high-intensity ultrasound is not a suggested approach for its extraction, according to the study.

One of the technologies deemed most suitable for lycopene extraction is magnetic stirring. This method does not create free radicals, which is ultimately deemed less harsh.

Furthermore, vegetable oils with a high unsaturated content were found to oxidize easily. Peanut oil, for instance, should not be used as a solvent in lycopene extraction.

“However, because olive oil allows for higher extraction ratios, it is strongly advised that it be used as a solvent to extract this type of carotenoids,” the study authors conclude.

In separate research, it was previously observed that pre-treatment with rosemary extract before lycopene boosts pro-collagen secretion to baseline levels.

By Mieke Meintjes