Enzymes, Heat and Storage

Question: Are enzymes inactivated at temperatures higher than 118 F?

Answer: Ah, the magical 118 number. When Edward Howell wrote his book on enzymes, he concluded that at above 118 degrees Fahrenheit (47 Celsius), all enzyme activity would cease. 

Dr. Howell wrote the bulk of his material between 1930 and 1950. Determining enzyme activity and temperature profiles was not a precise science back then. Actually, most plant-based enzymes are extremely hardy in regard to enduring high temps.

Most of the enzymes used in supplements are tested for activity at temperatures ranging from 110 to 140 F (43 to 60 C).

Enzyme tests are usually performed under conditions considered optimal for maximum activity, so these temperatures are nowhere near the danger zone.

The notion that one temperature (118 F or 47 C in this case) applies to all enzymes as the point of thermal inactivation is also not true. 

Enzymes are proteins. Resistance to heat varies with every protein, some are extremely sensitive, others are not. All fungal-derived and fruit-derived enzymes should be able to accommodate temperatures of 125 F (51 C) with no problem. 

Summer heat

Let's put the above information to practical use. Summer temperatures are often a concern to customers when it comes to shipping enzymes. 

However, this is not a problem as the packaging and bottle should provide adequate shielding from direct heating. 

What about the mailbox?

The worse scenario would be a package of enzymes left in a hot metal mailbox, but even this would have little effect on the enzyme activity. 

Several years ago, I tested some long-expired enzymes. They were sealed in the bottle and still in the cardboard box.  

They had been in a corner of my unconditioned garage in Arkansas for the past 8 years. Our summer temperatures will routinely be in the high 90s, with humidity in the 60 - 90% level. In the summer, my garage feels like a sauna.  

When we tested the enzymes, I was amazed to find that the activity was still above the amount stated on the label. 

We over-formulate our enzyme products, meaning that the amount you see listed on the label is less than what is put into the product. In this way, we can provide long shelf life and provide a good reserve of activity to accommodate extreme conditions. 

Even sitting in a mail truck or your mailbox for the weekend in Arizona will have little to no effect on the activity levels.

How to store enzymes

Since we are discussing temperature: If you want to prolong the shelf life of your enzymes, you can keep them in the bottle in the freezer. 

Don't put enzymes in the refrigerator for prolonged periods.Refrigerators have high humidity levels, freezers do not. 

Humidity is the worst enemy of enzyme activity, so take care to keep them in a dry place. 

Enzymes love the cold, so the colder the better. This is especially helpful for the chewable tablets as it keeps the tablets from getting soft (though this has no effect on the activity) which sometimes occur if a bottle is not completely emptied in a month or so. 

However, it’s fine to store your enzyme supplements in your cupboard or on the counter. Just keep the lid securely fastened.

Another comment bears repeating, though it may seem obvious. Don't cook the enzymes. Wait until any cooked food has cooled before adding or mixing enzymes. 

The rule of thumb is if it's cool enough to put into your mouth, it's cool enough to add enzymes.