Science Buddies: "Ask an Expert"

Hi,
It has been repeatedly mentioned in online articles that enzymes are not broken down yet in the upper stomach,as the upper stomach does not provide any digestive juices, but that enzymes in (raw) foods eventually get destroyed in the lower stomach, after staying for c.30 minutes in the upper stomach . Is there any scientific article from pubmed etc. which conclusively shows this? If you could provide me with such a link, I would be most grateful, as I am trying to include mention thereof in wikipedia, and they demand scientific studies to corroborate this. Thank you.

Geoff

Hi Geoff,

I could not find a specific article but I want to offer some insights.

Raw food do have enzymes. Enzymes are proteins (biological catalysts). The stomach (very low pH) releases both proteases (enzymes that break down proteins) and hydrochloric acid (HCl). Gastrin is one of the hormones that stimulates HCl release form parietal cells.

By the time plants and other raw foods reach the stomach, the enzymes will be denatured. HCl will disrupt the salt bridges and cause the protein to denature. In addition, the proteases will have an affect too.

More about protein denaturation here:

http://www.elmhurst.edu/~chm/vchembook/ ... ation.html

The "destruction" of enzymes from raw foods happens from both a molecular and physiological point of view.

I hope that helps!

Hi Geoff,

The other expert has already provided some great information for you. When it comes to finding articles, keep in mind that Wikipedia will often give you some citations that can get you started. Textbooks are also a good source of citations for basic physiological information.

I hope that helps. Let us know if you have more questions.

Heather