Posted by Sad Panda on October 11, 2004, at 5:56:06
In reply to Re: chicken soup for MAOI users? Simple solution. » Sad Panda, posted by Larry Hoover on October 10, 2004, at 8:45:17
> > Sorry to but in, but wouldn't chicken stock that has developed a funny smell and/or taste be highly suspect for tyramine content?
> >
> > I also think that if the cheese has any sort of smell or flavour then it would be wise to avoid it too.
> >
> > Cheers,
> > Paul.
>
> Tyramine is a biological product. You need fluid water to support bacterial biochemistry. That's why freezing works to preserve food.
>
> Off tastes from freezing are caused by oxidative degradation and water loss (such as by freezer burn). The rate of oxidation is slowed by temperature reduction (roughly halved for each 18 Fahrenheit decline in temperature), but not prevented altogether. Unsaturated fats slowly oxidize, and our noses are very sensitive to the products of those reactions because they can be indicative of food spoilage. (When we invented the freezer, we kind of messed with evolutionary drive. These oxidative products are not caused by bacteria, but our noses and brains don't know that.)
>
> Off tastes due to freezer burn are caused by cell rupture from the direct contact of air with the frozen food. Water leaves the surface even from frozen foods, via sublimation. That's why many frozen foods are vacuum packed. Any air in the package is bad news. That's why I am religious about getting air out of the packages I freeze.
>
> You could do an experiment. Freeze e.g. a whole fish just in a plastic freezer bag. Freeze an identical fish in a bag with sufficient water to totally envelop the fish, and with no air inside the bag. Wait six months, and thaw the fish. The quality of the fish will be extraordinarily different.
>
> Freezer degradation is not the same thing as bacterial action, so tyramine content is unaffected by freezing. Only during thawing, when fluid water is reformed, is bacterial action a concern. That's when tyramine can form.
>
> Lar
>I bow to your superior wisdom. :)
Cheers,
Paul.
poster:Sad Panda
thread:398156
URL: http://www.dr-bob.org/babble/20041007/msgs/401452.html