Many people like to use a pressure cooker to stew meat and pork ribs. What is the impact of pressure cooking on the nutritional value of meat? Research has found that compared to other cooking methods, stewing meat in a pressure cooker basically does not cause a reduction in protein, while also protecting fats from oxidation. The Nutrition Research Laboratory of China Agricultural University found that pressure-cooked fish better preserves fats compared to normal-pressure cooking, and the preservation rate of unsaturated fatty acids in the meat is also higher. This is mainly because pressure cooking creates an environment similar to a vacuum, reducing the contact between the meat and oxygen. This effectively reduces fat oxidation and, more importantly, decreases the production of harmful substances such as polymers that occur during fat oxidation, which is of great significance for health.
People also often use pressure cookers to cook coarse grains and legumes, which has many benefits. First, pressure cooking helps to preserve vitamins. Research has found that when cooking coarse grains and mixed beans with a pressure cooker, although the temperature rises from 100°C to 110°C, increasing losses from high heat, the cooking time is shortened from 60 minutes to 30 minutes, which reduces losses. The two factors offset each other, and there is no increase in the loss of B vitamins.
Second, pressure cooking helps to preserve antioxidant components. Pressure cooking prevents food from coming into contact with excessive oxygen, which is very beneficial for preserving the precious antioxidant components in coarse grains, such as polyphenols. Foreign studies have found that boiling can reduce the antioxidant capacity of beans. For example, after green peas are boiled at room temperature for 90 minutes, their Oxygen Radical Absorbance Capacity (ORAC, i.e., the ability to resist oxidation) is lost by 44%. However, when cooking beans with a pressure cooker, at the same level of softness, the loss of antioxidant properties is reduced. For instance, after green peas are pressure-cooked for 15 minutes, their ORAC not only did not decrease but actually increased to 224% of the original. Finally, pressure cooking aids digestion. The Nutrition Research Laboratory of China Agricultural University found that when cooking harder health foods like Chinese yam, Gordon Euryale seeds, lotus seeds, Job's tears, and red beans with a pressure cooker for 20 minutes, the digestion speed of these foods was significantly accelerated. Therefore, for people with indigestion, as well as the elderly and children who have weaker digestive systems, using a pressure cooker can help with digestion and reduce the burden on the gastrointestinal tract. Therefore, whether making congee or simmering soup, a pressure cooker is a healthy choice.
However, a pressure cooker is not all-powerful; it does cause a loss of vitamin C. Vitamin C is very delicate and is lost with almost all cooking methods. However, vitamin C is generally found in larger quantities only in vegetables and fruits, and we rarely need to cook vegetables and fruits with a pressure cooker.