How to make a drink from juice of the vitamin C-rich citrus fruit without destroying the goodness.
How to make a drink from vitamin C-rich lemons without destroying the goodness.
Does pouring boiling water over juice to make a lemon drink cause the same loss of nutrients as cooking some vegetables?
Superfoods, fresh foods, real foods – there’s much ado about which foods are the best nutrient sources. But you raise an equally, if not more, important point: how food is prepared has a big effect on the nutrients available to us. The factors that most affect vegetable nutrient loss are how finely the vegetables are chopped and the volume of water they’re cooked in. Many of us will remember parents or grandparents boiling vegetables such as cabbage or brussels sprouts in a saucepan full of water until they were unrecognisable by sight, smell or taste.
Whether you choose to microwave, steam or boil vegetables, leave them as intact as possible, and cook them in only a small amount of liquid to conserve water-soluble vitamins. The smaller you chop vegetables, the greater the surface area available for nutrient loss by leaching into the cooking water. Water-soluble micronutrients such as thiamine and other B vitamins, folic acid and vitamin C are particularly susceptible to leaching. They’re also damaged by heat. In contrast, fat-soluble nutrients such as carotenoids and vitamins A, D, E and K aren’t affected by cooking. Minerals are mildly affected by leaching but not by heat.
Cooking actually makes nutrients such as the lycopene in tomatoes more bioavailable. Canned tomatoes that have been heated during processing have more available lycopene than the raw fruit.
Lycopene is a carotenoid found in only a handful of fruits and
vegetables, including guavas, watermelons and pink grapefruit, giving them their red colour. It is an antioxidant and may be responsible for some of the health benefits of eating tomatoes and other vegetables, such as reducing LDL cholesterol levels and inflammation.
Lycopene-containing foods may also reduce cancer risk. A 2016 study, for instance, found that men who ate more lycopene had an 11% lower risk of prostate cancer than those who consumed the least.
So, what happens to lemon juice, a rich source of water-soluble and heat-sensitive vitamin C, when it is heated? Pakistani researchers investigated.
They found that at 25°C, lemon juice contained 10mg of vitamin
C per 100ml; at 50°C, the level was 9.33mg; and at the maximum tested temperature of 52°C, the level had fallen to 6.66mg.
In this study, the lemon juice was heated rather than boiling water being added, which would have meant it was hot for longer. The longer it is at a high temperature, the greater the damage to the vitamin C. Conversely, evaporation of water from the juice would have concentrated the vitamin C.
Since about twothirds of the vitamin C in the lemon juice was retained after the researchers’ heating, it’s probably safe to assume a significant proportion of the vitamin C in your lemon water would be retained even after boiling water was added.
But if you want to reduce losses, you could use very hot rather than boiling water, and drink it sooner rather than later to prevent more
You can reduce the vitamin C loss by using very hot rather than boiling water.