The Indian Council of Medical Research (ICMR) recently issued new dietary guidelines emphasizing the importance of closing lids while cooking. According to their findings, leaving pots uncovered during the cooking process could result in significant nutrient loss from foods.
ICMR stated that open lid cooking causes foods to take longer to cook, increasing the exposure to air. This accelerated loss of nutrients is avoided with closed lid cooking, as foods cook more rapidly with shorter cooking times. Though switching to covered cooking may cause greens and vegetables to darken in color, it helps better retain their nutrients.
Registered dietitian Kanikka Malhotra agrees, noting that open cooking could undermine the valuable vitamins and minerals in meals. Vitamins C and B along with folate are particularly vulnerable to prolonged cooking without lids and the leaching effect of evaporating steam. The consultant also pointed out that air promotes the degradation of fats, oils and vitamin C through oxidation when foods are left exposed.
According to Malhotra, leafy greens and brightly colored produce contain the highest amounts of water-soluble vitamins and antioxidants negatively impacted by uncovered cooking. Fatty fish are also prone to oxidation and rancidity. On the other hand, starchy vegetables and meat retain nutrients somewhat better due to their physical structure and nutrient profiles.
For those who regularly cook without lids, some techniques can help minimize losses. Using minimal water, pressure cooking, steaming, quicker cooking times and lidding whenever possible are suggested approaches. Blanching vibrant vegetables briefly also preserves their color and nutrition. Most importantly, choosing the freshest ingredients provides the highest starting levels of nutrients to retain despite cooking methods used.
