Sometimes I'm asked how I wash vegetables here in Japan. As you may know, most vegetables and fruits will have pesticides on the outer skin unless you grow it yourself. The Japanese Ministry of Health has a standard for the amount of pesticides to be used, so you don't need to be too worried but if you would like to be extra cautious, here are some helpful information.
Most of the time, I wash vegetables in tap water, which should be fine, but for some vegetables I use a vegetable washing powder to get rid of the pesticides . I've read that baking soda is also effective in getting rid of the pesticide. You need to get one that is suitable for consuming and not the ones for cleaning though.
The most effective way of getting rid of the pesticides is to peel the skin, but you don't want to do that as the skin contains the most nutrients and full of antioxidants. I normally leave the skin on unless I am eating it raw, such as for carrots as the residue on the skin may contain bacteria. Be sure to use a vegetable brush to clean your root veggies.
The vegetables I normally use the washing powder are strawberries (this contains loads of pesticides) and broccoli. You can tell that it is sprayed by pesticides by pouring water over broccoli as the water will roll over it as if it is coated in oil.
I haven't personally used this method but if you would like to use baking soda to get rid of the pesticides, just add 1-2 teaspoons of baking soda in a bowl of water and soak the vegetables or fruit for 30 seconds to 1 minutes (shorter time for leafy vegetables and rinse. Don't soak for longer as the vitamins and minerals will start to dissolve in the water. The scientific reason behind this is that the chlorine compound in the pesticide and the sodium bicarbonate (baking soda) joins together and becomes sodium chloride (salt).
If you are interested in the washing powder I use, It's called "ホタテの力 海の野菜洗い" It's made from the shells from scallops. The powder makes strong alkali powder which kills various bacteria including salmonella, E-coli, Fungus. It also has a preserving effect so the vegetables will last longer. You need to add 2-3 shakes of powder into a bowl of water and soak the fruit or vegetables for 5-10 minutes. and rinse.
You can buy both products on Amazon.
I'm Miyuki and I teach Japanese Home cooking at my home in Tokyo.