How do low-temperature enzymes survive kilning?

[frankvw]

As I understand it (I may be wrong) the lower the temperature at which an enzyme works, the lower the temperature at which it is denatured. Beta-glucanase, protease and peptidase, to name a few, work at fairly low temperatures, and when you mash at regular saccharification temperatures these enzymes show no activity at all which suggests denaturation.

My question: if these low-temperature enzymes denature below regular saccharification temperatures, how do they survive the much higher kilning temperatures to which the malt is exposed when it is dried in the maltings? Darker base malts (which have undergone more kilning than pale base malts) already show a lower diastatic power due to the increased destruction of amylase during kilning. If this is the case, how on earth can these low temperature enzymes survive kilning at all?

 

[Miraculix]

Because they are dry when being heated, the dry enzymes are kind of folded and can take heat much better.

 

[BeerChemistWhiskey]

Because they are dry when being heated, the dry enzymes are kind of folded and can take heat much better.

I work at a lab where we test many different enzyme activities, including protease, beta-glucanase, amylase, and many more not important to homebrewing. We have dry samples and standards that are several years old which will still test fine. Granted this is at room temperature.

But we have to test every sample within 30 minutes of being added to liquid - many will see a significant drop in activity after a short time in solution, even at room temperature.

 

[frankvw]

That tells me what I need to know. Thanks all!