pptculinary.pptx healthy lifestyle balance diet

ppt in culinary

1. How Food Becomes Nutrients : Digestion, Absorption, and Metabolism Good nutrition depends on the proper digestion of foods and beverages and the normal absorption and metabolism of their nutrients. DIGESTION Digestion is the process by which food and beverages are physically and chemically broken down into smaller components by the human body. These components are then absorbed and metabolized or stored for future use. Most foods and beverages undergo some form of digestion before they can be absorbed and used. Each stage of the digestive process is designed to break down carbohydrates, lipids and proteins into smaller parts and move them along for absorption and metabolism . Much depends on the nutrients that are contained in foods and beverages. A beverage may be digested faster than a piece of whole-grain bread , which may be digested faster than a chicken breast, which may be digested faster than a pat of butter. The more difficult a food or beverage is to digest, the longer the digestive process may be. Digestion may take 24 to 72  hours depending on food composition. Digestion really starts before a food or beverage ever comes close to the mouth. The appearance, aroma and sounds of foods and beverages arouse the senses and start the “digestive juices flowing.” Very appealing foods and beverages stimulate the central nervous system to anticipate what may follow. The brain and stomach communicate the deliciousness of foods and beverages through a maze of chemical transmitters. This triggers salivation and readies the body for digestion. Digestion then occurs in the mouth, stomach, and small and large intestines. Carbohydrates take the shortest amount of time before they are digested —sugars (especially liquids) as little as 30 minutes and starches around 2 to 3 hours. Protein takes longer—as much as 6 hours. Lipids take the longest—sometimes up to

2. Digestion in the Mouth The two types of digestion that take place in the mouth are chemical digestion, which occurs when enzymes are released by the salivary glands, and physical digestion, which occurs when food is chewed and moved to the back of the mouth with the help of the tongue. This is why it is important to chew food well and let it mix with saliva. People with eating and swallowing problems and those who do not produce sufficient saliva due to medical conditions might compromise the digestive process at this point. The enzyme that breaks down foods and beverages inside of the mouth is called salivary amylase. (The suffix “- ase ” indicates that it is an enzyme that is involved in a chemical reaction but stays intact.) Salivary amylase is then returned to its intact form to handle more foods and beverages. As foods are chewed and mixed with saliva, they form a bolus, or ball, that is moved toward the back of the throat to be swallowed into the esophagus. There is a cartilage flap that controls the bolus’s passage and prevents the bolus from entering the trachea, or the windpipe that leads to the lungs. It is called the epiglottis. When people choke on foods or beverages, it may be due to food accidentally entering the trachea instead of the esophagus. This may be due to speaking or laughing while there is food in the mouth, putting too much food in the mouth at one time, or not chewing food well. Choking may require the Heimlich maneuver, a series of under-abdominal thrusts to remove food quickly and prevent choking. Once the bolus is correctly swallowed, it is propelled by the esophagus, which is a short tube that leads to the stomach. Think of the esophagus as a band of strong muscles that pump and propel foods and beverages after they leave the mouth. 36 The esophagus is lined with saliva for moisture and protection. At the end of the esophagus is a muscle called the diaphragm that controls the movement of the bolus into the stomach and a valve, called the cardiac sphincter, which shuts the opening once the bolus has passed into the stomach. If the cardiac sphincter does not function properly, food from the stomach may move back into the esophagus. This is called acid reflux, which may be reduced by dietary changes, such as consuming smaller meals, medications or surgery.

3. FOOD BYTE Digestive enzymes help to break down proteins. Some digestive enzymes are derived from papayas (papain) and pineapples (bromelain), which are also found in supplement forms. Papain and bromelain are used in culinary applications as tenderizers. If they are overused, they can make protein foods too “mushy.” Cooked or canned pineapple does not have a tenderizing effect, since bromelain is heat-sensitive. Other digestive enzymes can help break down lactose (milk sugar) into a more digestible form and decrease the flatulence created by legumes (dried beans and peas).

4. Digestion in the Stomach Some, but not all, foods and beverages are digested in the stomach, a pouch at the end of the esophagus. The stomach is filled with hydrochloric acid, a strong acid that can digest protein foods and mucous and enzymes that break down other foods and beverages. These substances, along with muscular contractions, help to turn the bolus in the stomach into chyme, a semisolid mixture of partially digested food and gastric fluids, so it can be ready for its next passage. The next route for digestion depends on whether foods or beverages are comprised of carbohydrate, lipids or proteins. The stomach does very little to digest carbohydrates. Carbohydrates mainly move into the small intestine for additional digestion. Proteins are broken down by digestive fluids in the stomach, especially hydrochloric acid and the enzyme gastric protease. Little happens to lipids in the stomach. Instead, lipids head to the small intestine for additional digestion

5. Digestion in the Small Intestine The small intestine is not small; it is about 20 to 23 feet long and coiled inside the body. It is called the small intestine because its diameter is small. There are three sections in the small intestine: the duodenum, the jejunum and the ileum. The liver, gallbladder and pancreas are organs that secrete substances into the small intestine to further digest the chyme. By the time the chyme passes through the duodenum, jejunum and ileum, most of the nutrients are digested. The Liver, Gallbladder and Pancrea

6. The Liver , Gallbladder and Pancreas The liver is an essential organ for breaking down and processing nutrients. It is responsible for almost 500 critical functions in the human body. One of these functions is storage: the liver stores carbohydrates, lipids, minerals and vitamins. Because the liver processes alcohol and drugs, eliminates or transforms certain foreign substances that filter into our food supply, and restores new cells, it sustains a tremendous burden. The liver also produces bile, a substance that helps to digest fat, which is stored in the gallbladder. Unquestionably, the liver is absolutely essential in handling all the foods and beverages that are consumed. Unlike the liver, the gallbladder is a nonessential organ, which means that a person can live without it. The gallbladder serves to secrete bile into the small intestine for fat digestion. Bile is comprised of cholesterol, a type of lipid, and other substances including bile salts, cholesterol, fats, inorganic salts, mucus, pigments and water. The formation of gallstones, which are made mostly of cholesterol, may prevent the normal functioning of the gallbladder. Both gallstones and the gallbladder can be removed by surgery. If the gallbladder is removed, then a person needs to reduce his intake of fat and cholesterol, since there is no longer a place to store bile for fat management.

7. The pancreas is another vital organ in nutrient breakdown. Like the liver and gallbladder, the pancreas also secretes substances into the small intestine for digestion. The chyme that passes into the small intestine is acidic, thanks to the action of hydrochloric acid in the stomach. Secretions by the pancreas serve to neutralize this acid. The pancreas also produces enzymes that further digest carbohydrates, lipids and proteins. One of these enzymes is pancreatic amylase. The pancreas also produces two important hormones, insulin and glucagon, that are critical in the management of carbohydrates by the body. Insulin and glucagon help to maintain the level of blood glucose (sugar) in the body. Insulin is secreted by the beta cells of the pancreas in response to high blood glucose. In contrast, glucagon is secreted by the alpha cells of the pancreas when blood glucose is low (between meals and during exercise).

8. Digestion in the Large Intestine The large intestine is only five feet in length and larger in diameter than the small intestine. Like the small intestine, the large intestine has three sections: the cecum, the colon and the rectum. What is not absorbed by the small intestine passes into the large intestine and mixes with water and minerals. While the large intestine is essentially the holding and exiting site for foods, there also is some vitamin absorption from the bacteria that resides inside it. Strong muscles propel the release of the food residue

9. ABSORPTION Once food is digested, it is ready for absorption. Absorption is the movement of nutrients and other substances into the cells or tissues. Since most digestion is completed in the small intestine, the nutrients, which have already been digested into smaller substances, are now ready to move into the bloodstream and lymph throughout the body. Lymph carries body fluids that transport the by-products of fat digestion to the heart and back into the bloodstream. The other nutrients are carried by the bloodstream

10. Absorption in the Small Intestine Once carbohydrates are digested into their building blocks of simple sugars, lipids are digested into their building blocks of fatty acids, and proteins are digested into their building blocks of amino acids, they are ready to be absorbed. These building blocks of carbohydrates, lipids and proteins then join minerals, vitamins and water in the small intestine to move out and throughout the body. This movement is accomplished with the help of villi, little projectiles throughout the lining of the small intestine. Lined with muscles, these villi use wave-like motions to propel nutrients into the blood and lymph system. Then the portal system, which includes the liver, takes over. The word portal means “port” or “entryway.” Simple sugars, amino acids, water-soluble vitamins, and water are transported by the portal system. Fatty acids and fat-soluble vitamins are transported through the lymphatic system

11. Lipid (fat) Absorption Once dietary fats and oils, such as butter and olive oil, are digested into fatty acids, then the smallest fatty acids can pass into the cells that line the small intestine. They are fairly water soluble, so they can pass right into the bloodstream through the capillaries. These fatty acids then head to the liver, as does glycerol, a type of alcohol that is another product of lipid breakdown. The larger fatty acids require their own means of transport. Since fat and water do not mix (think about vinegar and oil salad dressing), the fatty acids need a “package” to help them travel through the bloodstream (which is mostly water). Protein that is supplied by dietary proteins encapsulates the fatty acids. This package of lipids and protein is called a lipoprotein.

12. Lipoproteins are delivered to the cells as they require energy. Excess lipoproteins are sent to the liver, which breaks them down and reformulates them. Some of the lipoproteins carry more lipids; some carry more protein. The lipoproteins with more protein are called high-density lipoprotein or HDL. High-density lipoproteins tend to be better for cardiovascular health than the lipoproteins that carry more lipids, which are called low-density lipoproteins or LDL.

13. METABOLISM Once the nutrients are sent to the cells, they need to be converted into energy for the many body functions. Metabolism is the sum of all of the physical and chemical processes by which energy is created and made available to the body. This energy can be used for such purposes as to build new body structures, including cells; heat the body; maintain or repair it; and provide energy for everyday activities and exercise. Simple sugars, fatty acids and amino acids, the building blocks of carbohydrates, lipids, and proteins, may also be combined into bigger and different compounds for the body to use. This process is called anabolism (as in anabolic steroids that are used to build muscles). Catabolism is the opposite process—when compounds break down, as in severe muscle wasting that might occur during certain diseases or eating disorders

14. Factors That Affect Metabolism Many factors affect the rate at which the body uses carbohydrates, lipids, and, to a lesser extent, proteins for energy. Some factors that raise the metabolism include caffeine, fever, growth, height, lean body mass, male gender, nicotine and stress. When a person is young, her metabolism is high. Also, tall, muscular men tend to have higher metabolisms than shorter and rounder women. The factors that lower the metabolism include age, fasting, hormones, sleep and starvation. As a person ages, his or her metabolism decreases. This is similar to what occurs during severe dieting. The hormones that are produced by the thyroid gland may either increase or decrease the metabolism if they are too high or too low. While sleep is important to good health, too much sleep means that the body is less active.

15. Bite on This: healthy digestion Healthy digestion begins with a healthy gastrointestinal tract. No matter how healthy foods and beverages are, various conditions, diseases, medications, stress and other factors may compromise normal digestion. A number of digestive disorders occur from simple stomachaches to those that require hospitalization. Digestive disorders include ulcers, heartburn, irritable bowel syndrome (IBS), vomiting, constipation, diarrhea, lactose intolerance, gluten intolerance—even “growling” and “hiccups.

16. ULCERS AND HEARTBURN The stomach and small intestine have protective linings that are filled with mucus and other substances. If hydrochloric acid eats away at the linings, then an ulcer, which is a small erosion or hole, may form. Ulcers may form in the esophagus, stomach or intestines. The bacteria that are associated with some ulcers may further irritate the linings. Stomach acid may also back up into the esophagus and lead to heartburn. It is called heartburn because it occurs in an area that is close to the heart. Although certain substances, such as acidic foods, alcohol, caffeine and fats have been implicated with heartburn, stress and frequent use of some medications, such as aspirin or ibuprofen, may also be to blame. Protective measures against heartburn include consuming small meals, increasing fiber in the diet and refraining from lying down after meals

17. IRRITABLE BOWEL SYNDROME, DIARRHEA, CONSTIPATION AND VOMITING In irritable bowel syndrome (IBS), spasms and/or cramps occur in the large intestine. Common symptoms of irritable bowel syndrome may include bouts of diarrhea and/or constipation. Generally a low-fat, higher-fiber diet is recommended. Probiotics, live microorganisms in plain yogurt or other cultured dairy products, may help to improve the intestinal microbial balance. Not all brands of yogurt contain “active” cultures, so check the food label. Some probiotics are added to cheese, breakfast cereals, protein and meal replacement bars and desserts. Most cases of diarrhea are caused by bacteria or viruses from foods or beverages. Severe and long-lasting diarrhea may lead to nutrient disorders and/or dehydration, as can vomiting. While vomiting is nature’s way of removing undesirable substances from the body, vomiting that is associated with illnesses or self-induced vomiting may have serious consequences. Constipation may be caused by a fiber-poor diet, inadequate fluids, lack of exercise and other physical or psychological issues. Increased fiber from breakfast cereals and other whole grains depends on adequate f luids to maximize its effectiveness in relieving this disorder

18. HICCUPS, GROWLING, AND FLATULENCE Hiccups are caused by involuntary spasms of the diaphragm muscle. This action sucks air down the trachea, or windpipe, into the lungs; causes the vocal cords to close; and creates a “hic-like” sound. Eating or drinking while taking in too much air might be to blame. If the stomach “growls,” it may mean that gas bubbles are present. When the stomach is empty, then growling may be louder. Flatulence is normal. It is frequently due to inadequate chewing, swallowing air while chewing, drinking beverages while chewing, or chewing gum. Other causes include consuming too many high-fiber foods, such as bran cereal or legumes; cruciferous vegetables, such as broccoli or cauliflower; foods high in fructose (fruit sugar) or sugar alcohols (such as sorbitol found in sugarless candy); or foods in the onion family, which require certain bacteria for breakdown

19. OTHER INTESTINAL CONDITIONS Lactose sensitivity or intolerance is provoked by the milk sugar lactose, and gluten intolerance is the inability to digest the protein in some grains. Both conditions are usually inherited and may require the avoidance of dairy products and certain grains. Look for more information about these carbohydrate-related diseases in Chapter 9. While there are over-the-counter and prescribed medications to help ease some of these digestive disorders, identification and/or elimination of any suspected foods and beverages might first offer some relief. Be sure to check any symptoms with a health care provider to rule out any other serious conditions and to develop a coordinated care plan

20. FOOD BYTE Processed foods have been transformed from their natural states into other forms for availability, consistency, convenience, safety and taste. Processing includes such procedures as canning, dehydrating, freezing and refrigerating. Many processed foods are nutritious, such as dairy milk or bread. Dairy milk is pasteurized to destroy bacteria and homogenized to keep fats blended. Bread is processed from flour, leavening and water. A stigma exists about the inclusion of processed foods in a healthy diet, although many basic and common foods are processed, including baking powder and baking soda, honey (unless raw) and salt. The inclusion of processed foods in a healthy diet should be kept in perspective

21. How cooking affects nutrition How Cooking Affects Nutrition 40 A food can be more or less digestible depending on the type of food, the temperature to which the food is heated, and the time it takes to cook the food. This is because cooking begins the digestive process by physically and chemically breaking down nutrients. Food processing may also influence the digestive process because it affects the bioavailability of certain nutrients. Some carbohydrate-containing foods, such as fruits and vegetables, can be consumed raw or they may only require partial cooking. More complex carbohydrates, such as the starches in grains and legumes, require longer cooking

22. Like carbohydrates, some proteins may be consumed raw or partially cooked. Raw fish in sushi, an uncooked egg in a Caesar salad, and raw ground beef in steak tartare are examples of protein in raw forms. However, any time protein is consumed raw, there is a risk of foodborne illness. Sear the fish to caramelize the exterior, boil the egg for a few minutes, and cook the ground beef to medium to destroy any microorganisms. Additionally, the heat will cause the proteins to slightly break down, or denature. Lipids are commonly consumed without cooking. Consider the fats that are contained inside avocadoes, olives or nuts, or the oils that dress fresh salads. When heat is applied to fats during cooking, this begins their lengthy breakdown. Overcooking fats may cause them to smoke or burn and create potentially harmful substances. More information about the healthy way to cook with fats and oils can be found in Chapter 6. Vitamins and minerals may be destroyed from overcooking. This is why many fruits and vegetables are better consumed raw or lightly cooked

23. Food as medicine Food as Medicine In Greek and Roman times, food was considered more than nourishment; it served as elixirs or aids to stay healthy and prevent and manage disease. Hippocrates, the Greek physician, connected the role of diet and disease. While some of his statements are not attributed to science, he did establish the possibilities of the nutrient-disease connection when he reportedly said, “Let food be thy medicine, and let medicine be thy food.” In some areas of the world, food is still considered Mother Nature’s best medicine, and people choose diets according to their health-enhancing benefits. Think about the traditional Chinese diet, with its balance of yin (feminine) and yang (masculine) foods. According to the Chinese, an unbalanced diet could result in illness.

24. Supposedly, excessive yin foods found in vegetables can lead to weakness, and excessive yang foods found in meat can lead to restlessness . Herbs and spices have long been recognized for their ability to prevent, manage, and even cure some diseases . For example, garlic and turmeric are used in some cultures to prevent some degenerative diseases and as remedies for others. Phytochemicals found in plant foods are associated with the prevention and management of certain diseases, such as beta-carotene in brightly colored orange and red fruits and vegetables. While not nutrients, phytochemicals have beneficial properties. They may ward off diseases, protect the eyes, and defend against the common cold, among other functions

25. Functional foods have physical and psychological roles in the diet. Some serve as antioxidants and protect the body against damaging free radicals from sunlight and environment hazards. Other functional foods help protect the bones, heart, and stomach, while still others help to reduce blood pressure and cardiovascular disease. Some functional foods are also called nutraceuticals; they act as pharmaceuticals, with druglike effects on the body

26. Finally, the emerging field of nutrigenomics or personalized nutrition offers immeasurable promise. Nutrigenomics applies the human genome (the entirety of an organism's hereditary information) to nutrition and health for individual dietary recommendations. It uses a person’s unique genetic makeup and nutritional requirements to tailor-make recommendations for disease reduction and health optimization. How can nutrition, food science and culinary professionals apply their skills to the rapidly growing interests in food as medicine? They must first have a solid foundation in nutrition, food science and the culinary arts. They should understand the complex roles that foods and beverages play in health and disease. And they should collaborate with allied health professionals to help translate the science behind medicinal foods into health-enhancing foods and beverages of the future.