An excellent source of amino acids, iron, calcium and other micro-nutrients, tofu is a versatile ingredient with many health benefits. Nutritionist Jo Lewin offers up recipes, research and the key nutritional highlights of this soya product...
An introduction to tofu
Tofu, or bean curd, is a popular food derived from soya. It is made by curdling fresh soya milk, pressing it into a solid block and then cooling it – in much the same way that traditional dairy cheese is made by curdling and solidifying milk. The liquid (whey) is discarded, and the curds are pressed to form a cohesive bond. A staple ingredient in Thai and Chinese cookery, it can be cooked in different ways to change its texture from smooth and soft to crisp and crunchy.
The origins of tofu
Like many soya foods, tofu originated in China. Legend has it that it was discovered about 2000 years ago by a Chinese cook who accidentally curdled soy milk when he added nigari seaweed. Introduced into Japan in the eighth century, tofu was originally called okabe. Its modern name did not come into use until 1400. By the 1960s, interest in healthy eating brought tofu to Western nations. Since that time, countless research has demonstrated the many benefits that soya and tofu can provide.
Nutritional highlights
Tofu is a good source of protein and contains all eight essential amino acids. It is also an excellent source of iron and calcium and the minerals manganese, selenium and phosphorous. In addition, tofu is a good source of magnesium, copper, zinc and vitamin B1.
Tofu is an excellent food from a nutritional and health perspective. It is thought to provide the same sort of protection against cancer and heart disease as soya beans.
| 70 kcal | 3.5g fat | 1.5g carbohydrate | 8.2g protein | 0.9g fibre |
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Research
Soya protein (from which tofu is derived) is believed to help lower levels of bad cholesterol (LDL). Tofu contains phytoestrogens called isoflavones – a group of chemicals found in plant foods. They have a similar structure to the female hormone oestrogen and therefore mimic the action of oestrogen produced by the body. They naturally bind to oestrogen receptor sites in human cells including breast cells – potentially reducing the risk of breast cancer.
Due to the phytoestrogen content of soya, many women decide to include soya rich foods like tofu in their diet as they enter the menopause. During the menopause, the body’s natural production of oestrogen stops and symptoms may arise. As phytoestrogens act as a weak oestrogen, they may help relieve symptoms by boosting levels slightly, reducing hot flushes in some women.
Genetics and environmental factors play a huge part in how our bodies react to certain foods, so as yet we can’t say whether a diet rich in phytoestrogenic foods is beneficial or not. If you are avegetarian or vegan, soya based foods like tofu can be an invaluable part of your diet.
How to select & store
Tofu can be found in bulk or individual packages, both of which are refrigerated. Tofu is also sold in sealed containers kept at room temperature, which do not need refrigeration until they are opened. When opened, all tofus needs to be rinsed, covered with water and kept in a refrigerated container. To keep the tofu fresh for up to one week, the water should be changed often. If kept in the original package, you can freeze tofu for up to five months.
Given its neutral taste and range of consistency, tofu has an amazing ability to work with almost all types of flavours and foods. Extra firm tofus are best for baking, grilling and stir-fries, while soft tofu is suitable for sauces, desserts, shakes and salad dressings. Of course, it is up to you to experiment! Try slicing, marinating and grilling it or chopping it up into smallish pieces and frying it with garlic until golden. Silken tofu is a creamy, softer product.
Safety
Tofu and all soya products contain large amounts of oxalate. Individuals with a history of oxalate containing kidney stones should avoid over consuming soya products. Women who have or have had oestrogen-sensitive breast tumours should restrict their soya intake to no more than four servings per week.
Source:By Jo Lewin - Nutritional therapist
http://www.bbcgoodfood.com/howto/guide/ingredient-focus-tofu
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