Can fresh kelp extract be frozen or refrigerated to extend shelf life?

[Orchid Whisperer]

I'm about to buy a new bottle of kelp extract. A 32 oz. bottle is more than I really need for the year, so from the start I plan to split it with a friend.

With my remaining pint, would freezing half of it preserve, or damage, it's root-promoting benefits? For the remaining 8 oz that stays liquid, is refrigeration beneficial?

[naoki]

Natural auxins (IAA) in kelp extracts can break down. According to some research, the light and heat is the enemy. So it is good to keep them refrigerated in opaque bottles. I haven't found anything against freezing. I'm guessing that it is probably ok to freeze, but some other people may know about it better.

Here is the study about heat and light stability:
http://digitalcommons.unl.edu/cgi/vi...agronomyfacpub

The research showed that natural IAA breaks easier than synthetic root hormones IBA and NAA. But according to Ray (actually according to the manufacturer whom Ray talked to), some kelp products (like KelpMax=KelPak) has some way to keep it stable longer. When he mentioned it, I didn't know the detail, but I now think that the manufacturer is probably talking about the "conjugation" with sugar.

This presentation talks about conjugation:
http://www.uky.edu/Ag/Horticulture/G...monesauxin.pdf

This paper talks that KelPak has conjugated forms of auxin derivative:
http://www.sajs.co.za/sites/default/...%20Article.pdf

Cytokinins are more stable, so Kelp extracts stored in high temp become closer to Keiki paste.

[estación seca]

I recall reading somewhere on Ray's page that KelpMax (the concentrate, as it arrives in the bottle) is stable for quite a while in the refrigerator. That's where I keep mine. I just might go through a quart / 946ml in a little less than a year. I use it a 2 Tablspoons / 30ml per gallon / 3.78 liters water.

[Orchid Whisperer]

Thanks for the feedback. I will definitely refrigerate, may research freezing a bit more. Naoki, I will definitely look at those linked articles - thanks!

[Ray]

Refrigeration, yes. Freezing, no. The formation of ice crystals can mechanically damage some of the contained molecules, even if the temperature does not.

[Orchid Whisperer]

Thanks Ray, I appreciate the advice!