Surprisingly, the way you cook your food has a major effect on the amount of nutrients it contains.
Cooking food improves digestion and increases the absorption of many nutrients (1, 2).
For example, the protein in cooked eggs is 180% more digestible than that of raw eggs (3).
Vegetables are generally a great source of vitamin C, but a large amount of it is lost when they’re cooked in water.
In fact, boiling reduces vitamin C content more than any other cooking method. Broccoli, spinach, and lettuce may lose up to 50% or more of their vitamin C when boiled (4, 5).
Because vitamin C is water-soluble and sensitive to heat, it can leach out of vegetables when they’re immersed in hot water.
B vitamins are similarly heat sensitive. Up to 60% of thiamine, niacin, and other B vitamins may be lost when meat is simmered and its juices run off.
However, when the liquid containing these juices is consumed, 100% of the minerals and 70–90% of B vitamins are retained (6).
On the other hand, boiling fish was shown to preserve omega-3 fatty acid content significantly more than frying or microwaving (7).
Grilling is one of the most popular cooking methods because of the great flavor it gives food.
However, up to 40% of B vitamins and minerals may be lost during grilling or broiling when the nutrient-rich juice drips from the meat (6).
There are also concerns about polycyclic aromatic hydrocarbons (PAHs), which are potentially cancer-causing substances that form when meat is grilled and fat drips onto a hot surface.
However, researchers have found that PAHs can be decreased by 41–89% if drippings are removed and smoke is minimized (8).
Short cooking times and reduced exposure to heat preserve the nutrients in microwaved food (9, 10).
In fact, studies have found that microwaving is the best method for retaining the antioxidant activity of garlic and mushrooms (11, 12).
Meanwhile, about 20–30% of the vitamin C in green vegetables is lost during microwaving, which is less than most cooking methods (5).
Although these terms are somewhat interchangeable, roasting is typically used for meat while baking is used for bread, muffins, cake, and similar foods.
However, due to long cooking times at high temperatures, the B vitamins in roasted meat may decline by as much as 40% (6).
With sautéing and stir-frying, food is cooked in a saucepan over medium to high heat in a small amount of oil or butter.
These techniques are very similar, but with stir-frying, the food is stirred often, the temperature is higher, and the cooking time is shorter.
Cooking for a short time without water prevents the loss of B vitamins, and the addition of fat improves the absorption of plant compounds and antioxidants (6, 13, 14).
One study found that the absorption of beta carotene was 6.5 times greater in stir-fried carrots than in raw ones (15).
In another study, blood lycopene levels increased 80% more when people consumed tomatoes sautéed in olive oil rather than without it (16).
On the other hand, stir-frying has been shown to significantly reduce the amount of vitamin C in broccoli and red cabbage (5, 17).
Frying involves cooking food in a large amount of fat — usually oil — at a high temperature. The food is often coated with batter or bread crumbs.
It’s a popular way of preparing food because the skin or coating maintains a seal, which ensures that the inside remains moist and cooks evenly.
Fatty fish are the best sources of omega-3 fatty acids, which have many health benefits. However, these fats are very delicate and prone to damage at high temperatures.
For example, frying tuna has been shown to degrade its omega-3 content by up to 70–85%, while baking causes only minimal losses (18, 19).
In contrast, frying preserves vitamin C and B vitamins, and it may also increase the amount of fiber in potatoes by converting their starch into resistant starch (20).
When oil is heated to a high temperature for a long period of time, toxic substances called aldehydes are formed. Aldehydes have been linked to an increased risk of cancer and other diseases (21).
The type of oil, temperature, and length of cooking time affect the amount of aldehydes produced. Reheating oil also increases aldehyde formation.
If you’re going to fry food, don’t overcook it, and use one of the healthiest oils for frying.
Steaming is one of the best cooking methods for preserving nutrients, including water-soluble vitamins, which are sensitive to heat and water (4, 5, 6, 17).
Researchers have found that steaming broccoli, spinach, and lettuce reduces their vitamin C content by only 9–15% (5).
The downside is that steamed vegetables may taste bland. However, this is easy to remedy by adding some seasoning and oil or butter after cooking.
It’s important to select the right cooking method to maximize the nutritional quality of your meal.
In general, cooking for shorter periods at lower temperatures with minimal water will produce the best results.
Alternative cooking methods such as grilling, roasting, steaming, stir-frying or microwaving generally preserve a greater amount of vitamins and other nutrients.
Cooking your meals has its benefits. It not only makes fiber more digestible but also enhances the absorption of several nutrients. However, it’s important to be aware of the drawbacks. Cooking can reduce the nutritional value of your food by destroying essential vitamins and minerals. Specifically, heat-sensitive vitamins such as Vitamin C, B1 (Thiamine), and B9 (Folic Acid) can lose up to half of their content during the cooking process.
However, this cooking method does not eliminate the issue of producing Maillard compounds, which are problematic substances that form during the browning of foods. Therefore, while it offers a good compromise, it should be used in moderation.
The French term “en papillote” refers to cooking ingredients in parchment (or aluminum foil). With this method, food is sealed in a pouch made from aluminum foil or parchment paper, then cooked in an oven or microwave. The food is protected inside the pouch, which helps to preserve nutrients.
Yet, not every cooking method impacts food the same way. Some techniques are more effective at preserving your ingredients’ nutritional quality. Generally, the shorter the cooking time and the lower the temperature, the better it is for retaining the food’s nutritional content.
There is wide disagreement among experts about the dangers of microwave cooking. Some believe that, if the microwave oven is not damaged, it cannot emit dangerous amounts of radiation.
In contrast, frying preserves vitamin C and B vitamins, and it may also increase the amount of fiber in potatoes by converting their starch into resistant starch (20).
With sautéing and stir-frying, food is cooked in a saucepan over medium to high heat in a small amount of oil or butter.
It’s a popular way of preparing food because the skin or coating maintains a seal, which ensures that the inside remains moist and cooks evenly.
For example, frying tuna has been shown to degrade its omega-3 content by up to 70–85%, while baking causes only minimal losses (18, 19).
Cooking food improves digestion and increases the absorption of many nutrients (1, 2).
How to Preserve Vitamins in Foods
FAQ
How do you preserve vitamins in food?
What are some practices to help preserve the vitamin content of food quizlet?
Which vitamin is used for food preservation?
Which of the following will help preserve vitamins and minerals when cooking fruit?
Why do vitamins lose a lot of nutrients when cooking?
The sooner you eat the food, the less chance of nutrient loss. The water-soluble vitamins, especially thiamin, folic acid and vitamin C, can be destroyed during improper storage and excessive cooking. Heat, light, exposure to air, cooking in water and alkalinity are all factors that can destroy vitamins.
What are the methods to maintain food hygiene?
Food hygiene ranges from the preparation, handling, and storage of food in order to reduce the risk of contamination and the occurrence of diseases, such as food poisoning. Some observations, wash your hands well with soap and water before preparing food; avoid using wooden utensils when preparing food, as this type of material favors the proliferation of microorganisms; tie your hair and do not wear rings, bracelets, earrings and watches.
How can i Improve my nutrient intake without supplements?
If you’re already eating at least 5 fist-sized servings of veggies each day, and want to improve your nutrient intake without supplements, consider: pairing complementary foods to maximize absorption. 4. Look to traditional or ancestral cuisines for cues. These diets have often figured out how to make the most of micronutrients. For instance:
What happens to B-vitamins during refining?
The B-vitamin content of a whole grain is dramatically decreased during the refining process. To counteract these losses, in the United States, food manufacturers are required to enrich or fortify breads and cereals from milled, refined grains with which B-vitamins? (Check all that apply):