Why and how does lycopene absorbance increase with heating?

Question

Lycopene, which is a carotenoid and a phytochemical is the main reason for why tomatoes are radio-protective.

Source 1, Source 2

Let's cut to the chase: I was wondering if this claim of this source is of scientific value:

"Heating will result in an increase in amount of lycopene absorbed by the body."

It may be possible that the researcher made a more "every-day" statement for the readers to understand.

I have two questions:

• Is the statement scientifically correct?
• If so, why and how would such a chemical be absorbed more with the heating process?

Note that if you want to make the argument that this is a biology question rather than a chemistry one, I would bring up these reasons:

• The temperature in which the heated lycopene and raw tomato are going to be absorbed in the body are the same. Thus, it might be possible that heating lycopene results in a chemical reaction.

• I'm not looking for the pattern of absorption by the body. I'm looking for possible changes or specifications of its structure.

Answer 1

"Heating will result in an increase in amount of lycopene absorbed by the body." Is the statement scientifically correct?

It is a poorly phrased statement, but it is probably generally true. It would have been better to say something like, "heating tomatoes will increase the amount of all-trans-lycopene available for ingestion."

Here's a link to a full paper on the subject (click the "View" button near the top-right of the page). Basically two things are going on at the same time when lycopene containg food is heated. It is the naturally occurring, all-trans isomer of lycopene that is thought to be beneficial to the human body. Heating lycopene causes it to isomerize to a variety of cis-isomers. Heating in the presence of oxygen can also cause oxidation. Both of these processes (isomerization and oxidation) reduce the potency of the lycopene in the broth.

However, in parallel with these deleterious effects, heating also makes more lycopene available in the heated broth or extract. This is because heating disrupts cell walls and releases lycopene from the cells. The above link shows that, at least at moderate temperatures, the latter effect predominates and so more active all-trans-lycopene is made available upon heating tomatoes, despite the loss of some lycopene to isomerization and oxidation.