My vegetables turn brown when I can them in a pressure cooker, why?

Question

I do not like to can via the cold can method, it takes to long. I have a lot of vegetables to can....how do I keep my corn, turnips and beets from changing color in a pressure cooker? I can potatoes, meat, tomatoes and sweet potatoes and they never loose their color. What can I do?

Answer 1

Hopefully you mean a pressure CANNER and not a pressure cooker? No pressure cookers are recommended as a substitute for a real canner because of the much shorter heat-up and cool-down times. This effectively shortens the correct processing period, and therefor results in an improperly processed and unsafe product. So be safe and use a proper canner.

You don't really have choice in processing methods when it comes to canning low acid foods like vegetables. They MUST be processed in pressure canner in order to reach the "safe" temperature of 240ºF that destroys all the bad little nasties that cause food poisoning and botulism.

Boiling water will never go beyond 212ºF. Even if you boiled the veggies for a year, the temp would get high enough to produce a safe product.

If you are turning out dark or discolored vegetables the likely cause is your technique. Even something as simple as iodized salt, or the gauge on the canner hasn't been tested, but the most common reason is due to incorrect processing which discolors vegetables when the natural sugars begin to caramelize.

If you aren't using current, tested canner directions that list processing times for your altitude, then get them updated. Follow them  precisely and without alteration and you will have success.

Answer 2

You can't. Its just that simple

Cold canning keeps the color.

When you heat up vegetables, you break down some cell walls and inner membranes, releasing chemicals which break down the clorophyll into other chemicals, which are brown tinted.

This is an oxidative process, almost the same as which happens to meat that has been sitting too long. It turns brown as well through oxidation.

If you want a nice vibrant color, your best bet would be the cold canning. It takes longer, but its the only way to really keep the beautiful color.

Your second best bet would be to add some ascorbic acid, Vitamin C, to the water before canning. Just crush up a Vitamin C pill into the water, 1 for every 2 cups of water should help.

This won't affect the taste much (you might notice it a little if eaten straight from the can), but Vitamin C is an antioxidant, which will help prevent some color change. It will still happen, theres no way to completely cure it, but it will help.

The potatoes are high in starch, which doesn't oxidize like sugar or chlorophyll.

Answer 3

its supposed to be so thats the mother natures rule but hey why can are you really living a a very remote area and far from civilization or too buzy but still abe to can food eat fresh by buying fresh thats and opinion for advice