Are Tangerine Tomatoes Healthier than Red Tomatoes? — Chromatography investigates

All tomatoes are the same right? Well, some are yellow or orange, some big or small. But basically, they are all tomatoes. Well, not quite it seems according to research published in the journal Food Chemistry. A team have published findings suggesting that not all tomatoes are equal. In the paper — A metabolomic evaluation of the phytochemical composition of tomato juices being used in human clinical trials — a team from Ohio State University has profiled tomatoes using chromatography. And they found that orange, or tangerine, tomatoes are slightly different to red tomatoes — and could be healthier for you.

Tomato — a super fruit, sorry vegetable

So, tomatoes — fruit or veg? It depends who you ask. Botanically, a tomato is a fruit, as botanists describe fruit as something that develops from the fertilized ovary of a flower. Peppers, pumpkins, sweetcorn are all fruits alongside apples, peaches and pears. So are tomatoes. A vegetable is botanically, all other edible parts of a plant that aren’t fruit. Tubers (potato), leaves (spinach, lettuce and cabbage) and flowers (broccoli and cauliflower) are vegetables.

But, according to the US Supreme Court in a ruling in 1893 tomatoes are vegetables too — a ruling that has its basis in how fruits and vegetables were taxed in the US at the time. But the way tomatoes are used, most people would recognize them as a vegetable. But either way — they are considered a superfood.

Full of juicy goodness

With over 10,000 varieties, tomatoes are classed by many as a food with super healthy benefits including in the fight against cancer, lower blood pressure and a healthier heart. They are packed with vitamins A, C and E and are even cholesterol free. But it is their source of phytochemicals that many people believe makes them a real superfood. One of the main chemicals in tomatoes is carotenoids — but it seems that not all tomatoes are equal.

Is your lycopene trans- or cis-?

Tomato juices are used in clinical trials testing health promoting foods. But are red and tangerine coloured tomato juices equivalent? That is what the team from Ohio set out to discover. The difference in colour is due to stereoisomerism in the lycopene molecule. Tomatoes are red because the geometric configuration is all trans- arranged. In tangerine coloured tomatoes the lycopene has a cis- arrangement. Research has previously suggested that the cis- arranged lycopene is more readily available — meaning we can use it easier for its health benefits. But what about other phytochemicals?

The team at Ohio used liquid chromatography to assess other phytochemical differences in orange and red tomatoes. The use of chromatography in food analysis is discussed in this article, LC-MS/MS and GC-MS/MS Multi Residue Pesticide Analysis in Fruit and Vegetable Extracts on a Single Tandem Quadrupole Mass Spectrometer.

They found significant differences between red and orange coloured tomatoes in the phytochemicals present — including carotenoids, neutral lipids and chlorophylls. So, orange tomatoes on your pizza from now on?