Using the right cooking methods is not enough as it is also important to choose the correct cooking utensils. Cooking results in chemical reactions between the food and the materials of the utensils leading to leaching of some of the minerals into the food. Let us examine the pros and cons of some commonly used cooking utensils.
Aluminium: Since World War II aluminium has been used worldwide for the manufacture of cookware and aluminium foil and wrappers. Aluminium cookware is cheap and light in weight. It has good heat conductivity, is easy to wash and clean and resistant to atmospheric oxidation. Aluminium cookware is highly reactive with acids, alkalis and salt and leaches into the food when dishes containing tomato, tamarind, lime juice, vinegar, kokum or soda bicarb are cooked or stored in them. Hence foods cooked in aluminium utensils should be transferred to glass, ceramic or steel utensils. Aluminium cookware that are worn out or pitted should be discarded as aluminium leaches easily from them. Aluminium is not an essential mineral for humans. Although there is no definite link, a number of scientific studies have shown the possible role of aluminium in the development of Alzheimer’s disease.
Copper: Copper along with its alloys – brass and bronze – has been used in the manufacture of cooking utensils since ancient times. These utensils are sturdy, resistant to scratching as well as atmospheric corrosion and are good conductors of heat. The disadvantage of these utensils is that they are easily corroded by fruit juices, acidic foods and salts to form poisonous compounds. In order to make the utensils safe for cooking their inner surfaces have to be coated with a layer of pure tin (that should not contain lead), a process known as kalai. This tin layer wears off due to use and scrubbing and needs to be periodically renewed. Copper is an essential trace mineral for humans and the practice of keeping water in a copper pot overnight is beneficial as it contributes some amount of copper to the diet.
Stainless steel: The use of stainless-steel cookware is becoming very popular today. Stainless steel is an alloy of iron along with chromium either alone or in combination with small amounts of nickel and molybdenum. Stainless steel does not react with the foods during cooking and can be safely used for cooking all types of foods.Unlike aluminium and copper which are good conductors of heat, stainless steel has less heat conductivity but this problem has been overcome by the availability of copper bottomed or sandwich bottomed stainless-steel utensils.
Earthenware: Since ancient times man has been using earthen utensils for cooking and storing food. These vessels were available in different shapes and sizes but are fast disappearing from our kitchens today. Earthen utensils are the safest for cooking as they are inert and do not react with the constituents of food and have good heating properties. Earthen utensils are somewhat porous and have a unique property of locking in steam and vapour that evaporates during cooking. Hence additional water does not have to be added resulting in better retention of nutrients in the food.
Food cooked in earthenware needs less oil and so the food has a lower content of added fat. Another advantage of cooking in earthen pots is that clay is alkaline and will interact with acidity in the food and neutralise the pH balance of the food. Food cooked and stored in earthen pots does not spoil easily even when stored at room temperature. Curd set in clay pots is tastier and thicker in consistency since the clay absorbs the extra moisture.
When using earthenware for the first time wash the cookware properly and boil some water in it to remove the earthy smell. Throw out the water, allow it to cool, wash the cookware again and use it for cooking.
To be continued…
(Writer is a consultant nutritionist with 20 years of experience, practicing at Panaji and can be contacted on firstname.lastname@example.org)