By Mrinal Pandit, Cheif Dietician, NephroPlus
Leaching as the word indicates extracting water-soluble vitamins and nutrient from foods items through a process. Leaching is indicated technically for cooking vegetables for people with CKD because the body (kidneys) can no longer maintain the ideal levels of potassium necessary for optimal health. Leaching is thought to drain out excess potassium and phosphorus from the vegetable, thus making it safe for consumption for people with CKD.
The standard traditional method for leaching of high potassium vegetables like roots, tubers and leafy vegetable goes as follows:
• Rinse the vegetable thoroughly
• Peel and soak it in cold water so they will not darken.
• Slice vegetable ½ inch thick.
• Rinse in warm water for a few seconds.
• Soak for about four hours in cold water.
• Cook vegetable with five times the amount of water to the amount of vegetable.
• Drain excess water and cook the vegetable as desired.
Now the questions is, as indicated does leaching process drain out all the potassium or it has own limitations?
Limitation of Leaching-
• It does not pull out potassium from all types of vegetable.
• It will not pull all the potassium from the vegetable.
• It drains out other essential nutrient along with potassium.
• The process needs to be followed meticulously for best results.
It was discovered that the traditional technique of leaching was not very effective and worth the time spent.
Recently, researchers found something interesting. Their study claims that double boiling is the only sure way to reduce potassium levels significantly in most vegetables. Boiling tuber cubes and shredded tubers decreased potassium levels by 50% and 75% respectively.
This study showed that double cooking appears to be more effective than normal cooking for leaching potassium especially from roots and tubers.This study was supported by a research grant from the National Kidney Foundation Council on Renal Nutrition.
As leaching removes all other essential nutrients and vitamins with potassium, it is suggested to leach only those vegetable, which are high in potassium, while other low to medium vegetables like Bottle gourd, Ivy gourd, Ridge gourd, Snake gourd etc. can be just be prepared for cooking by the method mentioned below. Click here to know more about low potassium vegetables and fruits.
Preparing low potassium fruits and vegetables for cooking.
-First peels off the outer layers and discard them.
-Fill up a basin with cold water and pour a half cup of vinegar in it.
-Soak your vegetables in the mixture for 5 to 10 minutes, swirling them around to loosen dirt and insects caught on the skin.
-Then transfer your vegetables to a colander and rinse under cold water.
This process helps you disinfect veggies, remove fertilizers, filth and other contamination and makes it safe for consumption.