I have a customer that is considering freezing whole sweet corn in the husks for storage and use at a later time. He is interested in freezing this sweet corn utilizing a CO2 freezer which operates at a temperature of -90F. I have several concerns with this process and would like your input if possible. First, what is the effect of freezing unblanched sweet corn on shelf life and quality, second, is there an issue with freezing the corn in the husk including the silks? Do you think that the corn will keep and that the enzyme activity will slow down and allow for storage longer than 20 days without blanching prior to freezing? (A.G.)
Freezing is a process commonly used to preserve vegetables, including sweet corn, and it can successfully retain the quality and nutrients in a safe manner, as long as there is not a lot of temperature fluctuation during frozen storage. For effective freezing, the lower the temperature the better. There may be some changes in texture, but these will be minimized if you are able to use a fast, low temperature process. The CO2 is actually advantageous because this decreases exposure to air, which may promote oxidation. As far as freezing in the husks, this is not a common practice and unfortunately I don’t have experience with this, therefore you may need to do some preliminary tests with a small amount of corn to try it. The enzymes will still be present if the corn is not blanched, but as long as you keep it cold they will have very low activity. That's why I said it's best not to have temperature fluctuations....if the temperature goes up the enzymes become more active. You need to reduce the time between when the corn is frozen, thawed and consumed. Otherwise that in-between period can result in quality loss.