Cooking effects on nutrients
To improve health and energy levels, nutritious food intake is essential. Some fruits and raw vegetables can be taken by removing the skin but this may cause the elimination of some of their vitamins, minerals and fibre. Generally, raw foods contain unfriendly bacteria along with the healthy ones, which may be pathogenic and disease-causing.
To remove them, cooking is essential, as cooking the food destroys harmful bacteria.
The bacteria responsible for the most common food poisoning, Salmonella, are killed after an hour at 550C and in 20 minutes at 600C.
Cooking also destroys toxic substances present in some plants and makes the starch in rice, potatoes and in other foods digestible.
Cooking improves the appearance, texture and flavour of food and also makes it tastier.
The method by which food is cooked has an intense effect on nutritional value. This is of particular importance if food has to play a part in overcoming an illness. The way of cooking will determine the extent to which food retains its valuable nutrients.
Although cooking improves digestion and the absorption of many nutrients, the levels of some vitamins and minerals may decrease.
Any form of cooking inevitably results in the loss of some nutrients. These losses can be kept down to a minimum by various cooking methods and by making sure that food is not over cooked.
On the other hand, inadequate cooking of food causes food poisoning.
The nutrients reduced during cooking are
Water-soluble vitamins: Vitamin C and the B vitamins — thiamine (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), folic acid (B7) and cobalamin (B8) are easily lost by leaching into the cooking water.
Fat-soluble vitamins: Vitamins A, D, E and K.
Minerals: Primarily potassium, magnesium, sodium and calcium
Different cooking methods are
Water-based cooking methods are boiling, simmering and poaching. These methods differ in water temperature.
Cooking methods with dry heat are Grilling and broiling.
Microwave cooking is a safe cooking method as it preserves most nutrients due to short cooking time and reduced exposure to heat.
Cooking food in an oven with dry heat methods are Roasting and baking.
Sautéing and stir-frying methods require medium to high heat and a small amount of oil or butter.
The Barbeque method is similar to grilling and is used to get rid of the fat from the meat.
Roasting is one of the easiest method of cooking large cuts of meat and poultry.
Deep Frying in oil requires high temperature and this method is considered to be the unhealthiest of all cooking methods.
Steaming method is considered to be the second best after microwaving in the retention of nutrients including water-soluble vitamins.
No specific method of cooking retains all nutrients. To minimise loss of nutrients, food has to be cooked for shorter periods at lower temperatures with a minimum amount of water. To maximize the nutrients contents of the food, the right cooking method has to be selected.
By following certain tips, nutrient loss while cooking the food can be reduced.
- Vegetables should be cooked in smaller amounts of water and for only a few minutes to reduce loss of vitamin C and B vitamins. Liquid left in the pan after cooking vegetables should be consumed in the form of soup.
- To retain vitamin C content, consume vegetables within a day or two otherwise vitamin C content may be reduced as the cooked food is exposed to air.
- Avoid using baking soda when vegetables are cooked. Because vitamin C will be lost in the alkaline environment produced by baking soda.
- Use only fresh ingredients and cook foods quickly.
- To retain the fibre content of the food, vegetables should not be peeled until cooked completely.
- Meat, poultry and fish should be cooked in the shortest time for safe consumption.
- Juices that are dripped from the meat into the pan should be added back to the meat.