Then, you simmer the meat and vegetables with seasonings, a moist technique. The objective of combination cooking is to build upon food flavors.
Perfect Timing Perfectly cooked vegetables should be colorful and flavorful. What happens to vegetables that have been overcooked? If you understand each type of cooking technique, you can combine them in ways that create great-tasting food.
You will learn more about how to use combination cooking techniques in Section Distinguish What are the key differences between the dry, moist, and combination cooking techniques? A food's nutritive value, texture, color, aroma, flavor, and appearance do not stay the same after cooking. The cooking technique you choose can affect all of these factors. It is important to know how food will change after it is cooked. The length of time food is cooked and the cooking technique you use determine how much nutrition a food will retain.
Raw foods lose more nutritive value the longer they cook. In fact, certain cooking techniques can actually speed up nutrient loss. For example, boiling green beans extracts nutrients in two ways.
Nutrients are destroyed simply because the green beans are exposed to heat. Nutrients also are lost during boiling because they are diluted in the liquid. You might think that if you steam the green beans, you will maintain all of the nutrients. Although steaming is one of the best ways to minimize nutrient loss, exposure to heat will still extract some nutrients from the green beans.
However, because the vegetables are cooked by the steam, and not in water, they will not lose nearly as many nutrients as if they had been boiled. If you have ever overcooked vegetables, you have seen how cooking can change the texture of food. During cooking, moisture is lost, food tissue breaks down, and proteins coagulate. All of these factors change the texture of cooked food.
When heat is applied, the proteins in food coagulate. This means that they change from a liquid or semiliquid state to a drier, solid state. The longer that you subject, or expose, the proteins to heat the firmer and more solid they will become.
For example, compare the difference in t exture between a soft-cooked egg and a hard-cooked egg. If you simmer an egg for three to five minutes, you will produce a soft-cooked egg with a partly solid white and a semiliquid yolk.
To produce a hard-cooked egg with both a solid white and yolk, the egg must be simmered for 8 to 10 minutes. The length of time cooked will affect the texture of the egg white and yolk. Coagulation also occurs in meat proteins as heat is applied during cooking. Meat proteins lose some moisture as the protein becomes more solid during cooking. Long, slow cooking techniques and moderate heat will make some meats tender, flavorful, and juicy. However, using too much heat can toughen the protein in those same meats.
This happens because too much moisture is lost. The cooking process also affects the color of food. For example, certain ingredients that are commonly used to cook vegetables, such as lemon juice, vinegar and baking soda, can change the color of vegetables. There are cooking techniques, such as blanching, that can help keep the color of vegetables. You will learn about blanching in Section Fruits and vegetables get their unique colors from naturally occurring pigments.
A pigment is the matter in cells and tissue that gives them their color. Common pigments in foods include chlorophyll green vegetables , flavonoids red, purple, and blue vegetables , and carotenoids yellow, orange, and red vegetables.
Many foods have more than one type of pigment. Remember that the longer that fruits and vegetables are cooked, the more their color will change. Likewise, as meat cooks for extended periods of time, moisture is extracted. The meat will lose its deep-red color as it cooks. These color changes happen at different temperatures. Texture Changes When highprotein foods are cooked, their texture changes.
How can you tell which egg has been cooked longer? That is why the inside of a rare steak is red, a medium rare steak is pink, and a well done steak is brownish gray. Similar to chlorophyll, carotenoids are also fat-soluble colorants, which means cooking methods involving the use of fats may also cause leaching of the pigment. As well as leaching, carotenoids can undergo oxidation, which occurs when the carotenoid cells come into direct contact with the air and react with oxygen molecules.
This reaction leads to the degradation of the pigment. Cooking methods, which expose fruits and vegetables containing carotenoids to the atmosphere for long periods of time e.
Anthocyanins are found in fruits such as blueberries, cherries and red plums, and vegetables such as red potatoes and aubergines, whilst anthoxanthins are found in fruits such as apples, and vegetables such as cauliflower, onions and potatoes. Both anthocyanins and anthoxanthins are water-soluble pigments and thus may leach into cooking water during soaking or prolonged heating.
Cooking methods avoiding water such as stir-frying will thus minimise the loss of these flavonoids during heating. Fruit and vegetables. The cooking methods that may result in pigment loss are boiling, frying, grilling, steaming and roasting. Many foods contain proteins, such as meat, fish, eggs, vegetables, nuts and pulses.
Proteins are large molecules, composed of strands of amino acids, which are linked together in specific sequences by the formation of peptide bonds. Proteins form different 3-dimensional structures, by the folding and subsequent bonding of the amino acid strands. Generally, the bonds which link the folded amino acid strands together mostly hydrogen bonds , are much weaker than the strong peptide bonds forming the strands. During cooking, the heat causes the proteins to vibrate violently, which results in the breakage of the weak hydrogen bonds holding the amino acid strands in place.
Ultimately, the protein unravels to re-take its initial form of amino acid strands. The denaturation of protein molecules in foods usually causes a substantial change to the texture of the product. For example, egg white is composed of two key proteins; ovotransferrin and ovalbumin.
As the egg white is heated, ovotransferrin begins to denature first, entangling and forming new bonds with the ovalbumin. As the temperature increases, ovalbumin then starts to denature, unravelling and forming new bonds with the ovotransferrin, until denaturation and rearrangement of the protein molecules are complete. In this case, the rearrangement of the protein molecules results in the change of a runny, fluid texture to a rigid, firm texture.
Conversely, protein denaturisation can also cause the formation of softer textures. For example, the protein collagen, which is the major component of the connective tissue in meat, has a tough, chewy texture. However, during cooking, the weak hydrogen bonds are broken and the protein begins to decompose and react with water molecules to form gelatine.
This tenderises the meat, giving it a softer, more palatable texture. Any foods containing protein e. The cooking methods that may result in protein denaturation are boiling, frying, grilling, roasting, steaming and baking. This is because the cooking of these foods causes a process known as starch gelatinisation.
The starch granule is made up of two polysaccharide components, known as amylose and amylopectin. Amylose has a linear chain of glucose units, whilst amylopectin has a branched structure of glucose units. When cooked in water, the starch granules absorb water and swell. At the same time, amylose leaches out of the granules and bonds to form organised lattice structures, which trap the water molecules causing the thickening of the mixture.
Any foods containing starch e. The cooking methods that may result in starch gelatinisation is boiling. Many plant foods, in particular vegetables, maintain their rigidity by the incorporation of polysaccharides such as cellulose and pectin in the plant walls.
As with the degradation of starch, cellulose and pectin can also be broken down into their monosaccharide constituents during cooking, resulting in the substantial softening of foods containing these polysaccharides. Foods containing polysaccharides such as cellulose and pectin e. The cooking methods that may result in polysaccharide degradation are boiling, frying, grilling, roasting and baking.
Vitamins are essential nutrients, without which the body cannot function properly. There are two main types of vitamins; water-soluble and fat-soluble Table 4. As the name suggests, water-soluble vitamins are highly soluble in water and tend to be found in foods that have high water contents such as fruits and vegetables. Similarly, fat-soluble vitamins are highly soluble in fat and tend to be found in foods that have high fat contents such as dairy products, vegetable oils and oily fish.
The differences in vitamin solubility mean that the method by which foods are cooked has a substantial influence on the final vitamin content. Due to their tendency to disperse in water, water-soluble vitamins in particular are heavily affected by cooking processes that involve immersing food in water for long periods of time e. In contrast, fat-soluble vitamins tend to be lost during cooking processes where foods are cooked in fat e.
As well as the cooking medium, the length of heating can also affect the vitamin content of foods. Both fat-soluble and water-soluble vitamins are susceptible to heat, with the latter being particularly sensitive. Short cooking methods such as stir-frying and blanching help to reduce the heat degradation of vitamins, compared to longer cooking methods such as roasting.
Any foods containing vitamins e. The cooking methods that may result in the loss of vitamins are frying, boiling, grilling, steaming and roasting. As with vitamins, minerals are also essential nutrients, without which the body cannot function correctly. There are two types of minerals, known as essential minerals and trace elements. Heating itself does not affect mineral levels but are usually leached if cooked in boiling water.
Minerals tend to have a higher heat stability and are less affected by cooking methods which involve heating foods for longer periods of time.
Any foods containing minerals e. The cooking method that may result in the loss of minerals is boiling.
Over recent years, it has become evident that cooking foods can lead to the generation of undesirable compounds. The generation of potential carcinogenic compounds has received particular attention due to the serious nature of their possible consequences. Perhaps the most well known of these compounds are nitrosamines. Sodium nitrite is used for the curing of meat and the associated smoked taste, the prevention of bacterial growth and a desirable dark red colour.
During cooking, nitrosamines are produced from nitrites and secondary amines. They are found in some smoked, grilled or fried foods, such as charred meat, and they can also be found in tobacco. Furan, formed by several pathways, is a volatile chemical that tends to evaporate quickly. However, when it cannot escape for some reason e. Polycyclic Aromatic Hydrocarbons PAHs are produced when any incomplete combustion occurs, from grilling roasting and frying, but also smoking and drying dependant on fat content.
Most PAHs are not carcinogenic, although a few are such as pyrene and benzo a pyrene. Foods containing starch and protein e. The cooking methods that may result in the generation of undesirable compounds are frying, baking, grilling, smoking and roasting. Despite the fact that cooking can cause the generation of undesirable compounds, research has shown that cooking can also increase the formation of favourable molecules and the bio-availability of some antioxidants, such as lycopene.
Unlike heterocyclic amines and acrylamide, antioxidants are known to be beneficial to human health. Antioxidants are molecules that can slow down or prevent other molecules from undergoing reactions that can cause damage to human cells.
Antioxidants are also generated during the Maillard Reaction. Mostly starchy foods e. The cooking methods that may result in the generation of desirable compounds are frying, baking, grilling and roasting. Cooking therefore has a substantial impact on the final sensory organoleptic , nutritious and health properties of many different foods.
Table 5 provides a summary of the main cooking methods and the effect they can have on the final characteristics of cooked food. Polysaccharide degradation, loss of pigmentation, protein denaturation, polysaccharide gelatinisation, vitamin loss, mineral loss.
The food industry in Europe is made up of approximately , companies and employs over 4 million people. The manufacturing of food products across Europe is diverse, varying from small-scale units, producing handmade products to large-scale, highly automated factories producing tonnes of products per day.
However, regardless of the volume of food being manufactured, the process is the same as that in the kitchen at home, but just on a larger scale. 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. 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. 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. 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.
Frying makes food taste delicious, and it can provide some benefits when healthy oils are used. It's best to avoid frying fatty fish and minimize the frying time of other foods. Steaming is one of the best cooking methods for preserving nutrients, including water-soluble vitamins, which are sensitive to heat and water. 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. Steaming is one of the best cooking methods for preserving nutrients, including water-soluble vitamins.
There are many ways to preserve the nutrient content of foods without sacrificing taste or other qualities. 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.
Reposted with permission from Healthline. For detailed source information, please view the original article on Healthline. About Contact Us. Learn more Got It. Most recent. Top 6 Apps for Secondhand Clothing reuse. Solar Energy. Cost of Solar Panels in What to Expect solar energy.
Are Solar Panels Worth It? Our Honest Take solar energy. The 6 Best Antioxidant Supplements of supplements. The best of EcoWatch, right in your inbox. Sign up for our email newsletter! Enter Email
0コメント