Tomato seeds could form basis of new functional oil

Tomato seeds could provide the basis for the development of new oils with high antioxidant functionality, according to a paper published by the Journal of Food Science.

Tomato seeds are typically treated as a waste by-product of tomato processing. However, according to the research team led by Zhongli Pan of the Agricultural Research Service of the United States Department of Agriculture (USDA), implementing appropriate techniques allows an oil high in antioxidants to be developed.

The research team looked at a number of process variables, including time, temperature, solvent-to-solid ratio and particle size. Increasing temperature, solvent-to-solid ratio, and extraction time increased oil yield.

In contrast, larger particle size reduced the oil yield. The recommended oil extraction conditions were 8 min of extraction time at temperature of 25 °C, solvent-to-solids ratio of 5/1 (v/w) and particle size of 0.38 mm, which gave oil yield of 20.32% with recovery rate of 78.56%.

The research provides the groundwork for the possible commercial production of an oil with a high content of unsaturated fatty acids, especially linoleic acid.

The research was driven by the need to maximise the value of the tomato crop, which is said to be around 130 million tonnes each year. Around a third of this is consumed in processed products. Seeds account for up to 5% of the total weight of the crop, and would usually be used in animal feed or disposed of as waste.

Tomatoes are already used in functional food products as they contain significant quantities of lycopene, which has antioxidant functionality. Lycopene has been considered a potential agent for prevention of some types of cancers.