Table of Contents
Cooking: The standard procedure as a nutrient killer?
Experts define cooking as “cooking in liquid at a temperature of around 100 degrees Celsius”. Pasta, rice or certain types of vegetables are placed in boiling water and cooked over medium heat until al dente.
Which nutrients are lost during cooking?
Cooking in plenty of liquid causes high losses of the water-soluble vitamins B1, B2, B6 and C. If the cooking water is not subsequently part of the dish – such as in a soup – then conventional cooking reduces the specified vitamins in the dish by up to 60 Percent. This also applies to vegetables that are cooked in their skins, such as jacket potatoes.
Cooking alters nutritional content positively and negatively
A Chinese study examined the effect of different preparation and cooking methods on the nutritional content of rice. As a result, conventional cooking caused
- a loss of B vitamins and bioactive phytic acid
- a loss of zinc and manganese
- better availability of iron, magnesium and calcium.
The harmful effects on vitamins and phytochemicals were more pronounced the higher the cooking temperature.
Are there any health risks when cooking?
Anyone who cooks their food in plenty of water as a habit should at least occasionally eat meals with grain products and raw food with an increased vitamin C and vitamin B content in order to compensate for a possible deficiency.
Overall, however, conventional cooking offers the advantage of largely killing off potential microorganisms. Some foods are also easier to digest when cooked: the toxic phasin in legumes is broken down when heated and the carotenoids from carrots, pumpkin and sweet potatoes are more readily available to the organism when cooked than raw.
Steaming: Slow Cooking for the Health Bonus?
Steaming describes cooking in a little water or in steam at around 100 degrees Celsius. Fish, meat or vegetables are placed in a pot with just enough liquid to cover the bottom. Alternatively, you can put the food in a sieve through which the steam from the liquid boiling underneath flows.
What about nutrient retention during steaming?
Since steamed foods come into contact with significantly less liquid, water-soluble ingredients such as vitamins B and C are not washed out as much. The loss of vitamins for the eater is also minimized if the liquid is used at the end of cooking to prepare the dish – for example bound as a sauce. Home economists expect a 10 to 25 percent loss of the water-soluble minerals and vitamins when steaming.
Are there any health risks?
Per se, steaming is considered to be a cooking method that is particularly gentle on nutrients and digestible . People who want to lose weight prefer to use them, since fat can be largely avoided when steaming. However, too little fat in the meal inhibits the absorption of certain vitamins such as A, D, E and K. Steamed dishes should therefore also be refined with a little cold-pressed vegetable oil.
Baking – how many vitamins go to waste in the oven?
When baking in the oven, the food cooks in dry heat at around 120 to 250 degrees Celsius. The method is suitable for bread, cakes and pizza, as well as certain types of vegetables such as potatoes, sweet potatoes and pumpkin. If, on the other hand, a roast is prepared in a covered pot in the oven, it is called braising.
What is the nutrient loss in baking?
The advantage here is that the food does not come into contact with water. Jacket potatoes in the oven are one of the gentlest cooking methods for the starchy tuber. However, since some ingredients are sensitive to heat, baked goods lose around ten to twelve percent of their vitamin B and C content.
By the way, if you value a calorie-reduced diet, you can take a few simple steps to ensure this when baking.
Are there any health risks? When cooking carbohydrate-rich foods in the oven, the by-product acrylamide
is formed at high temperatures . It forms when sugars such as fructose and glucose, the amino acid asparagine and a low water content in the food come together with heat above 120 degrees. From 180 degrees, some baked goods even show a sharp increase in their acrylamide content.
According to research by the European Food Safety Authority (EFSA), acrylamide intake increases the potential risk of cancer in consumers of all ages. Its metabolite glycidamide is considered the most likely cause of tumor growth and gene mutations in animal experiments. In order to reduce acrylamide intake – especially in children, who quickly consume a relatively large amount of it in relation to their weight – the following rules must be observed when baking:
- Baked rolls and toast should be baked golden yellow instead of brown in the oven. The lighter the crust of the baked goods, the less acrylamide they contain.
- Ovens with top and bottom heat should be heated to a maximum of 200 degrees Celsius for dough and potato products; Ovens with convection at a maximum of 180 degrees.
- For french fries, cutting larger and thicker potato sticks and using parchment paper will help lower acrylamide levels. Halfway through the cooking time, ideally turn the fries to the other side.
- Egg yolk and baking soda in cookies reduce acrylamide levels, while staghorn salt as a leavening agent and roasted almonds and nuts increase them.
Crickets – does a lot of smoke cause big risks?
Grilling is the generic term for various cooking methods that have one thing in common: the cooking process takes place via radiant heat from coal or gas flames and via contact heat with the grill grate. But within this framework there are different grilling methods:
- Direct grilling: Here the food is directly above the heat source and is briefly exposed to very high temperatures of around 230 to 290 degrees. Hobby and professional grillers like to use this process to sear steaks and chops.
- Indirect grilling: Inside a closed grill, the ingredients are not directly above the heat source, so the heat generated cooks them evenly throughout the interior of the grill. Temperatures of 160 to 200 degrees are common, but reduced cooking temperatures are also possible if the time is extended accordingly.
- Smoking in a smoker: The smoker is particularly common in the USA, where meat was given its characteristic smoke flavor in this way as early as the 19th century. Due to the special design of the device , the cooking chamber and fireplace are separate, so that the ingredients are prepared within indirect heat. Due to the closed cooking chamber, the smoker is also suitable for cooking at low temperatures (70 to 90 degrees). Wood chips or pieces that burn up inside the connected firebox provide the smoke that flows through the cooking chamber and gives the meat a typical smoked aroma.
Like the oven, every grill works with dry heat – the loss of water-soluble vitamins and minerals is therefore relatively small at ten to twelve percent.
When barbecuing, there is a risk that carcinogenic substances will form , such as so-called polycyclic aromatic hydrogens (PAH) or heterocyclic aromatic amines (HAA). The consumption of large amounts of these substances is considered to be risky in relation to adenomas, which in turn form the precursor to colon cancer. When grilling, the formation of HAA cannot be completely avoided, because they always form when protein-containing foods are heated. However, the level increases significantly if the products are grilled too hot or too long.
The PAH content of grilled food is particularly high when it comes into direct contact with smoke gases. This primarily happens when fat and marinade drips from the meat onto the embers, burns there and then comes into contact with the food as smoke. Deglazing the grilled food with beer serves the aroma, but also produces smoke and thus higher PAH values in the food.
Care should be taken when cooking salt meat on the grill at high temperatures. Cured food contains nitrite curing salt, which can be converted into nitrosamines at high temperatures. These substances are considered a risk factor for esophageal and gastric cancer.
Roast – a greasy treat?
Pan frying is undoubtedly one of the favorite cooking methods in this country when it comes to steaks and cutlets. Hot oil cooks meat and fish at around 140 to 190 degrees Celsius and gives them an appetizing crust through the so-called Maillard reaction . Sugar and proteins in the food are converted to dark and aromatic pigments, so-called melanoidins, in a multi-stage process.
Does frying damage the nutrient content?
Since the food in the frying pan is exposed to the heat for a relatively short time and no water is involved, the loss of vitamins is relatively small at seven to ten percent. When it comes to the health value of fried meat, many people believe that the well-cooked proteins in fried meat are easier to digest. A rare steak would therefore be more difficult to digest than a piece of meat that was well-done.
A French study in 2017 revealed that this difference is of little importance for young consumers. However, meat eaters over the age of 70 can metabolize well-done meat much more efficiently and obtain a higher content of the amino acid leucine from it than from short-cooked meat.
Are there any health risks?
When roasting, the slightly lower temperatures potentially produce less acrylamide than in the oven. However, the cooking method is only suitable to a limited extent for everyday healthy eating due to the high fat content of the food in question, especially breaded pieces of meat and fish.
The type of frying fat is also decisive for the health value of the food. A distinction is made here between fats with a high smoke point, which contain predominantly saturated fatty acids, and fats with a low smoke point, which provide plenty of unsaturated fatty acids. Although the latter are preferable in salads, they run the risk of burning when fried, releasing carcinogenic substances.
Fats and their smoke point
- Fats with a high smoke point (above 200 degrees): palm fat, peanut oil, clarified butter, refined sesame oil, refined grapeseed oil, refined olive oil, refined canola oil
- Medium smoke point fats (160 to 190 degrees): butter, extra virgin olive oil, toasted sesame oil, argan oil, walnut oil, extra virgin canola oil
- Fats with a low smoke point (below 160 degrees): safflower oil, hemp oil, linseed oil
Sous-Vide – haute cuisine with health benefits?
In the sous vide process, food is cooked in a vacuum bag in a water bath. The temperatures are in the range between 50 and 90 degrees. Because the effect of heat is moderate and there is no contact with water, particularly aromatic and juicy dishes succeed. Meat and fish, which are cooked in a vacuum, are then fried for about 30 seconds on each side so that the Maillard reaction creates additional roasted aromas.
How gentle is sous vide on the nutrient content?
During sous vide cooking, the water-soluble vitamins B and C do not come into contact with liquid, so losses are minimal. Some minerals and trace elements are even present in higher proportions in vacuum-cooked foods. A study, in which beans, peas, lentils and pearl barley were prepared using the sous vide method, showed significantly higher levels of iron, potassium, zinc and copper. The food here provided up to 800mg more per portion compared to conventionally cooked food.
Does sous vide cooking pose any health risks?
If food is prepared for a very long time (more than four hours) at comparatively low temperatures of 50 to 60 degrees, the risk of food germs multiplying during this time increases. Vacuum-cooked foods are not sterile after preparation like boiling-point meals and should therefore be consumed immediately or frozen immediately.
The right materials are also important: Sous-Vide bags must be tested by the manufacturer for pollutant limits to guarantee that no components of the plastic migrate into the food during the water bath.
Does sous vide cooking pose any health risks?
If food is prepared for a very long time (more than four hours) at comparatively low temperatures of 50 to 60 degrees, the risk of food germs multiplying during this time increases. Vacuum-cooked foods are not sterile after preparation like boiling-point meals and should therefore be consumed immediately or frozen immediately.
The right materials are also important: Sous-Vide bags must be tested by the manufacturer for pollutant limits to guarantee that no components of the plastic migrate into the food during the water bath.
Frying – better than its reputation?
When frying, food is cooked floating in hot fat, with the temperature of 160 to 170 degrees being slightly lower than in the frying pan and in the oven. The Maillard reaction gives meat a tasty crust, while breading and pastry shells are baked in fat until golden brown.
How many nutrients are lost in the fryer?
As far as nutrient loss from water-soluble minerals and vitamins is concerned, the fryer produces food that is better than its unhealthy reputation: only seven to ten percent of the nutrients mentioned are lost here.
What are the health risks?
There is a risk of acrylamide formation in the fryer, but it is somewhat lower than in the oven. Frying French fries below 175 degrees and limiting the time to 3.5 minutes significantly reduces the formation of pollutants. In addition, the choice of fat is decisive for the potential health impact of deep-frying – after all, the eater absorbs relatively large amounts of it through breading and dough coatings.
Which fat is suitable for frying?
Even if it is generally said that cold-pressed vegetable oils are more healthy than refined ones, this does not necessarily apply to the fryer. Here, when native vegetable oils are heated to high temperatures, trans fatty acids can form, which in turn are considered a risk factor for arteriosclerosis and heart attacks.
Refined oils or vegetable fats such as coconut or palm fat, which consist mainly of saturated fatty acids, are better. If the frying fat is filtered after the first run, it can definitely be used one or two more times. For good results at low temperatures, cut meat and vegetables into relatively flat pieces so that the inside is cooked when the casing turns golden.
Microwaves – vitamin-sparing radiation sources
Here, the water molecules are made to rotate inside food with the help of electromagnetic waves and the food in question heats up in a very short time. This method is suitable for both defrosting and reheating, and for cooking food.
How many vitamins are lost in the microwave?
Since the microwave works with relatively short cooking times and little liquid is required, the water-soluble vitamins in particular are largely retained. Depending on the length of the cooking time, you have to assume a loss of between five and 25 percent.
Are rays harmful to health?
In fact, human tissue, especially the eyes, can be damaged by exposure to microwaves. But as a rule, the common microwave oven models shield this radiation from the outside by almost 100 percent. If the microwave door no longer closes properly or is cracked, the device should no longer be used. Contrary to all concerns, the electromagnetic waves in the food do not form any carcinogenic residues. Another advantage of the microwave: as little browning takes place, most foods do not produce acrylamide.
Conclusion: It always depends on the individual case
With water, with oil, with hot air – the world of cooking methods is diverse and constantly takes on new dimensions thanks to innovative kitchen aids. It is not possible to make blanket judgments about the health suitability or unsuitability of a method.
The fact is: When cooking gently with little liquid, most of the nutrients are retained. However, all other cooking methods also have their place in a varied diet if you follow certain rules.
