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Food biochemistry
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Food biochemistry




-Main biomolecules
-Water soluble vitamins
-Fat soluble vitamins



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Food biochemistry Presentation Transcript

  • 2. Food BiochemistryOutline:• Main biomolecules• Water soluble vitamins• Fat soluble vitamins• Minerals
  • 3. Food BiochemistryA healthy diet- is one that helps maintain or improve health. It is importantfor the prevention of many chronic disease such as: obesity,heart disease, diabetes, and cancer- a healthy diet involves consuming appropriate amounts of allnutrients, and an adequate amount of water- nutrients can be obtained from many different foods, so thereare a wide variety of diets that may be considered healthydiets.- contains all the seven groups of nutrients; carbohydrates,proteins, fats, vitamins, fibers, mineral salts and water incorrect proportions
  • 4. Main BiomoleculeCarbohydrates- the bodys main source of energy. There are three differentkinds of carbohydrates.- they include starch, sugar, and fiber. Starch is made fromchains of small sugars.- we get 4 calories from each gram of starch (or sugar). We donot get calories from fiber because our bodies do not breakfiber down during digestion.- plant foods like cereals, bread, rice, pasta, potatoes, plantainsand corn are good sources of starch. They give us the energywe need to do daily activities. These starchy foods give usimportant vitamins and minerals, too.
  • 5. Main BiomoleculeCarbohydrates- because carbohydrate-rich foods are usually low in calories,they can help us keep a healthy weight.- sugar is a source of empty calories. The higher the intake ofempty calories, the greater the risk of an inadequate nutrientintake, an excessive calorie intake, or both- sugars as well as starches promote dental decay by feedingbacteria in the mouth that produce an acid that damagestooth enamel- too much can cause behavioral problems in children, obesity,diabetes mellitus and heart disease
  • 6. Main BiomoleculeFat- fat is a nutrient that is an important source of calories. Onegram of fat supplies 9 calories - more than twice the amountwe get from carbohydrates or protein.- fat also is needed to carry and store essential fat-solublevitamins, like vitamins A and D.- when we eat a lot of high fat foods, we get a lot of calories.With too many calories, we may gain weight. Eating too muchfat may also increase the risk of getting diseases like cancer,heart disease, high blood pressure or stroke.- we should get no more than 30% of our calories from fat toreduce our risk of getting these diseases.
  • 7. Main BiomoleculeFat- fat is found in many foods. Some of the fat that we eat comesfrom the fat we add in cooking or spread on breads,vegetables or other foods. A lot of fat is hidden in foods thatwe eat as snacks, pastries or prepared meals.- we can reduce the amount of fat we eat by cutting down onthe fat that we add in cooking or spread on foods.- we can eat skim milk and low fat cheeses instead of wholemilk and cheese. We can also use less fat, oil, butter, andmargarine.- another way to cut down on fat is to drain and trim meats andtake the skin off poultry.
  • 8. Main BiomoleculeProtein- a component of every living cell- 20 common amino acids; 9 are considered essential becausethe body cannot make them--indispensable; they must beconsumed through food; 11 are considered nonessentialbecause they can be made by the body if nitrogen and otherprecursors are available - dispensable- provides structure and framework in the body- plays a role in fluid balance and acid-base balance- used to transport substances through the blood- provides 4 cal/g of energy
  • 9. Main Biomolecule- most experts recommend that protein contribute 10% to 20%of total calories in the diet- the quality of proteins varies: complete or incomplete- complete proteins, those with high biologic value, provideadequate amounts and proportions of all essential aminoacids needed for protein synthesis necessary to support tissuegrowth and repair- animal proteins and soy protein are complete proteins- incomplete proteins lack adequate amounts of one or moreessential amino acids- except for soy protein, all plants are sources of incompleteproteins. Gelatin is also an incomplete protein
  • 10. Main BiomoleculeHigh Protein Diets- many dieters believe a high protein diet is superior to a highcarbohydrate diet in promoting weight loss- people who choose to eat a high-protein diet in an attempt tolose weight should be reminded to choose low-fat sources ofprotein to keep calories under control:- low-fat or skim milk and milk products- lean cuts of meat and skinless poultry that are baked,broiled, or roasted- egg whites, whole eggs- dried peas and beans
  • 11. Main BiomoleculeProtein Supplements- some people take amino acid capsules or powders, based onthe belief that the more protein the better- but normally people take more protein than needed.- so why take supplements? More is not better- people most vulnerable to adverse effects of proteinsupplements include pregnant and lactating women, infants,children, and adolescents, the elderly, people who need tolimit their protein intake (e.g., people with liver or renaldisease)
  • 12. Vitamin- do not provide energy (calories) but they are needed formetabolism of energy- function as coenzymes to activate enzymes- the body needs vitamins in small amounts (microgram ormilligram quantities) - micronutrients- are essential in the diet because they cannot be made by thebody or they are synthesized in inadequate amounts- vitamins are classified as either water-soluble or fat soluble- their solubility determines how they are absorbed,transported through the blood, stored, and excreted- in humans there are 13 vitamins: 4 fat-soluble (A, D, E and K)and 9 water-soluble (8 B vitamins and vitamin C).
  • 13. VitaminWater Soluble Vitamin- dissolve easily in water, and in general, are readily excretedfrom the body- because they are not readily stored, consistent daily intake isimportant.- many types of water-soluble vitamins are synthesized bybacteria.- are considered nontoxic- adverse side effects, however, can occur from takingmegadoses of certain water-soluble vitamins over a prolongedperiod
  • 14. VitaminFolic Acid- is important for making blood and building cells. It is alsocalled folate or folacin.- found in plant foods like leafy greens, broccoli, corn andwhole grains are good sources of folacin. Cowpeas, lentils,kidney and navy beans are good sources, too.- some meat and milk products like eggs, liver, nuts, cheese,and milk are also ways to get this vitamin.- the need for folic acid increases during pregnancy because thefetus is constantly growing. If a pregnant woman does not getall the folic acid she and her baby need early in her pregnancy,the fetus will not develop properly.
  • 15. VitaminNiacin- works with other B vitamins to help your body use the energyyou get from food. It is also important to help use proteinfrom the diet to build new cells and tissues.- most kinds of meat, poultry and fish are good sources ofniacin. "Enriched" grains, like breads, rice, pasta, cereals andother baked products are also sources of niacin.- easily lost when foods are cooked or processed. When youcook rice , some of the niacin goes into the water. When yourinse rice, you rinse off some of the vitamin.- to keep the niacin you need from these foods, it is importantnot to rinse the rice after you have cooked it.
  • 16. VitaminRiboflavin- another name for riboflavin is vitamin B2.- works with other B vitamins to help your body use the energyyou get from food. It also helps the body to use protein infood to build new cells and tissues.- animal products, like milk, cheese, yogurt, beef and poultry,are good sources of riboflavin. Some green vegetables such asbroccoli, turnip greens and spinach are good too. "Enriched"breads, rice, cereals and other baked products are alsosources of riboflavin.- like other B vitamins, riboflavin is easily lost when foods arecooked or processed.
  • 17. VitaminThiamin- another name for thiamin is vitamin B1.- works with other B vitamins to help your body use the energyit gets from food.- found in many whole grain foods, such as brown rice, gritsand whole wheat bread. White breads, pastas, ready-to-eatcereals and many other baked products are "enriched" by themanufacturer with B vitamins like thiamin. Baked beans, blackbeans, black-eyed peas, and peanuts are good sources ofthiamin, too. Nuts, seeds and other vegetables, and fruitssupply a small amount of this B vitamin. Lean pork is one ofthe best sources of thiamin. Organ meats such as liver, heartor kidney, are also a good animal sources of thiamin.
  • 18. VitaminVitamin B6- helps the immune system produce antibodies. Vitamin B6helps maintain normal nerve function and form red bloodcells. The body uses it to help break down proteins.- Vitamin B6 is found in beans, nuts, legumes, eggs, meats, fish,whole grains, and fortified breads and cereals.- large doses of vitamin B6 can cause neurological disorders andnumbness.- deficiency of this vitamin can cause mouth and tongue sores,irritability, confusion, and depression.
  • 19. VitaminVitamin C- helps form a cement-like material between our cells. We needvitamin C to heal cuts, wounds, and burns. When we dont getenough vitamin C the "cement" between cells loses itsstrength and can cause us to bleed easily. It can also help inpreventing certain types of cancer.- found in many fresh fruits like the oranges, lemons, limes,grapefruit, cantaloupes, mangoes, papayas, and their juices.Vegetables such as bean sprouts, green peppers, plantains,broccoli and greens like kale and poke greens are also goodsources of vitamin C.- we need some vitamin C every day because is not stored inthe body
  • 20. VitaminFat Soluble Vitamin- fat-soluble vitamins are absorbed through the intestinal tractwith the help of lipids- because they are more likely to accumulate in the body, theyare more likely to lead to hypervitaminosis than are water-soluble vitamins.- fat-soluble vitamin regulation is of particular significance incystic fibrosis- because they are stored in liver and adipose tissue, vitaminsA, D, E, and K do not need to be consumed daily- vitamins A and D are toxic when consumed in large quantitiesover a long period
  • 21. VitaminVitamin A- helps form and maintain healthy teeth, skeletal and softtissue, mucous membranes, and skin. It is known as retinolbecause it produces the pigments in the retina of the eye.- It promotes good vision, especially in low light. It may also beneeded for reproduction and breast-feeding.- retinol is an active form of vitamin A. It is found in animalliver, whole milk, and some fortified foods.- comes from animal sources, such as eggs, meat, milk, cheese,cream, liver, kidney, cod, and halibut fish oil. However, all ofthese sources except for skim milk that has been fortified withVitamin A are high in saturated fat and cholesterol.
  • 22. Vitamin- carotenoids are dark colored dyes found in plant foods thatcan turn into a form of vitamin A.- one such carotenoid is beta-carotene. Beta-carotene is anantioxidant- sources of beta-carotene are carrots, pumpkin, sweetpotatoes, winter squashes, cantaloupe, pink grapefruit,apricots, broccoli, spinach, and most dark green, leafyvegetables. The more intense the color of a fruit or vegetable,the higher the beta-carotene content. These vegetablesources of beta-carotene are free of fat and cholesterol.
  • 23. VitaminVitamin D- two major forms which are vitamin D2 (ergocalciferol) andvitamin D3 (or cholecalciferol).- vitamin D obtained from sun exposure, fortified food, fish oil,fatty fish and supplements, is biologically inert and mustundergo hydroxylation reactions to be activated in the body.- the major role is to increase the flow of calcium into thebloodstream, by promoting absorption of calcium andphosphorus from food in the intestines, and reabsorption ofcalcium in the kidneys- it is also necessary for bone growth and bone remodeling byosteoblasts and osteoclasts
  • 24. VitaminVitamin D- without sufficient vitamin D, bones can become thin, brittle,or misshapen.- deficiency can arise from inadequate intake coupled withinadequate sunlight exposure; disorders that limit itsabsorption; conditions that impair conversion of vitamin Dinto active metabolites, such as liver or kidney disorders; or,rarely, by a number of hereditary disorders. Vitamin Ddeficiency results in impaired bone mineralization and leadsto bone softening diseases, rickets in children andosteomalacia in adults, and possibly contributes toosteoporosis
  • 25. VitaminVitamin E- is an antioxidant that protects body tissue from damagecaused by unstable substances called free radicals.- also important in the formation of red blood cells and helpsthe body to use vitamin K- at lower levels, vitamin E may help protect the heart.- the best way to get enough essential vitamins is to eat abalanced diet that contains a variety of foods. Wheat germ,corn, nuts, seeds, olives, spinach and other green leafyvegetables- products made from these foods, such as margarine, alsocontain vitamin E.
  • 26. VitaminVitamin K- vitamin K is known as the clotting vitamin, because without itblood would not clot. Some studies indicate that it helps inmaintaining strong bones in the elderly.- found in cabbage, cauliflower, spinach and other green leafyvegetables, cereals, soybeans, and other vegetables. It is alsomade by the bacteria that line the gastrointestinal tract.- vitamin K deficiency is very rare. It occurs when the body cantproperly absorb the vitamin from the intestinal tract. Can alsooccur after long-term treatment with antibiotics.- individuals with vitamin K deficiency are usually more likely tohave bruising and bleeding.
  • 27. VitaminNutrient Incidence of Deficiency Typical Symptoms and DiseasesBiotin UncommonDermatitis, eye inflammation, hair loss, lossof muscle control, insomnia, muscleweaknessFolic aciddeficient in 100% of elderly inone study; deficient in 48% ofadolescent girls; requirementdoubles in pregnancyAnemia, apathy, diarrhea, fatigue,headaches, insomnia, loss of appetite,neural tube defects in fetus, paranoia,shortness of breath, weaknessNiacin Commonly deficient in elderlyBad breath, canker sores, confusion,depression, dermatitis, diarrhea, emotionalinstability, fatigue, irritability, loss ofappetite, memory impairment, muscleweakness, nausea, skin eruptions andinflammation
  • 28. VitaminNutrient Incidence of Deficiency Typical Symptoms and DiseasesPantothenicacid (B5)Average elderly diet contains60% of RDAAbdominal pains, burning feet, depression,eczema, fatigue, hair loss, immuneimpairment, insomnia, irritability, low bloodpressure, muscle spasms, nausea, poorcoordinationPyridoxine(B6)71% of male and 90% offemale diets deficientAcne, anemia, arthritis, eye inflammation,depression, dizziness, facial oiliness,fatigue, impaired wound healing, irritability,loss of appetite, loss of hair, mouth lesions,nauseaRiboflavin Deficient in 30% of elderlyBlurred vision, cataracts, depression,dermatitis, dizziness, hair loss, inflamedeyes, mouth lesions, nervousness,neurological symptoms (numbness, loss ofsensation, "electric shock" sensations),seizures. sensitivity to light, sleepiness,weakness
  • 29. VitaminNutrient Incidence of Deficiency Typical Symptoms and DiseasesThiamin Commonly deficient in elderlyConfusion, constipation, digestiveproblems, irritability, loss of appetite,memory loss, nervousness, numbness ofhands and feet, pain sensitivity, poorcoordination, weaknessVitamin A 20% of diets deficientAcne, dry hair, fatigue, growth impairment,insomnia, hyperkeratosis (thickening androughness of skin), immune impairment,night blindness, weight lossVitamin B-12Serum levels low in 25% ofhospital patientsAnemia, constipation, depression,dizziness, fatigue, intestinal disturbances,headaches, irritability, loss of vibrationsensation, low stomach acid, mentaldisturbances, moodiness, mouth lesions,numbness, spinal cord degeneration
  • 30. VitaminNutrient Incidence of Deficiency Typical Symptoms and DiseasesVitamin C 20 to 50% of diets deficientBleeding gums, depression, easy bruising,impaired wound healing, irritability, jointpains, loose teeth, malaise, tiredness.Vitamin D62% of elderly womens dietsdeficientBurning sensation in mouth, diarrhea,insomnia, myopia, nervousness,osteomalacia, osteoporosis, rickets, scalpsweatingVitamin E23% of male and 15% offemale diets deficientGait disturbances, poor reflexes, loss ofposition sense, loss of vibration sense,shortened red blood cell lifeVitamin KDeficiency in pregnant womenand newborns commonBleeding disorders
  • 31. Antioxidant VitaminFree Radicals- are produced continuously in cells as they burn oxygen duringnormal metabolism- problem - they oxidize body cells and DNA in their quest togain an electron and become stable- these structurally and functionally damaged cells are believedto contribute to aging and various health problems such ascancer, heart disease, and cataracts
  • 32. Antioxidant VitaminAntioxidants- substances that donate electrons to free radicals to preventoxidation- antioxidants protect body cells from being oxidized(destroyed) by free radicals by undergoing oxidizationthemselves, which renders free radicals harmless- vitamin C, Vitamin E, and beta-carotene are majorantioxidants
  • 33. VitaminVitamins and special needs populations- it is recommended that women who are capable of becomingpregnant consume 400 micrograms of folic acid throughsupplements or fortified food daily- people over the age of 50 are urged to consume most of theirB12 requirement from supplements or fortified food- vegans need supplemental B12 and D, if exposure to sunshineis inadequate- other groups who may benefit from taking a dailymultivitamin are the elderly, dieters, finicky eaters, andalcoholics
  • 34. Water- involved in almost every body function. Is not stored butexcreted daily- largest single constituent of the human body, averaging 60%of total body weight- although most people can survive 6 weeks or longer withoutfood, death occurs in a matter of days without water- occupies essentially every space within and between bodycells and is involved in virtually every body function- in medicine, body water is all of the water content of thehuman body
  • 35. WaterFunction- provides shape and structure to cells- regulates body temperature- aids in the digestion and absorption of nutrients- transports nutrients and oxygen to cells- serves as a solvent for vitamins, minerals, glucose, and aminoacids- participates in metabolic reactions- eliminates waste products- is a major component of mucus and other lubricating fluids
  • 36. WaterCalculation of body water- water is abundant in most parts of the body, except in adiposetissue (fat). These calculations are for adults of average build,and are inappropriate for obese or overly muscular people.- broken down into the following compartments; intracellularfluid (2/3 of body water), extracellular fluid (1/3 of bodywater), plasma (1/5 of extracellular fluid), interstitial fluid (4/5of extracellular fluid)- the simplest calculation is the 60-40-20 rule.Total Body Water = 60% of body weightIntracellular fluid = 40% of body weightExtracellular fluid = 20% of body weight
  • 37. WaterInput-output- under normal conditions, water intake equals water output tomaintain water balance- in most healthy people, thirst is a reliable indicator of need- the body’s need for water is influenced by many variables- a general guideline is to consume 1.0mL of fluid per calorieconsumed, with a minimum of 1500mL/day- on average, adults lose approximately 1450 to 2800mL ofwater daily
  • 38. Minerals- minerals are inorganic substances that cannot be brokendown and rearranged in the body- functions in structure, fluid balance, acid - base balance,nerve cell transmission and muscle contraction, vitamin,enzyme, and hormone activity- minerals toxicities are not likely to occur from diet alone. It ismore often related to- excessive use of mineral supplements- environmental exposure- alterations in metabolism
  • 39. MineralsClassification- electrolytessodium, potassium, and chloride are electrolytes becausethey carry electrical charges when they are dissolved insolution- macromineralsneeded in relatively large amountsfound in the body in quantities greater than 5 g- trace mineralsneeded in very small amountsfound in the body in amounts less than 5 g
  • 40. MineralsCalcium- for healthy strong skeletal structure and teeth.- Additionally calcium is important for functioning of muscularand nerve systems. Important for the health of the skeletalsystem of growing young children.- the best sources of dietary calcium are dairy products, milk,cheese, eggs, fruit, almonds, seaweeds (kelp,wakame,hijiki),nuts, legumes, breads and cereals.- deficiency of calcium can impair the proper formation andmaintained of bones and teeth formation.- excess in calcium intake can lead to stone formation in thekidneys (calcification)
  • 41. MineralsMagnesium- very important essential mineral that helps to maintainmuscles, bones and nerves- also it is very important in regular heart rhythm and in proteinsynthesis. Participates in more than 300 biological reactions inthe body.- best dietary sources for magnesium are dark greenvegetables, spinach, seeds, nuts, grains and fruits.- deficiency of the mineral magnesium can result insensitiveness to noise, irritability, mental depression,twitching, trembling, apprehension, confusion, insomnia,muscular weakness and fingers, toes, feet or legs cramps.
  • 42. MineralsPotassium- electrolyte that involved in body fluid balance within cells- it is also very important in controlling heart activity and thoseof the nervous and muscular systems, regulate water in thebody and balance pH of blood and all tissues. The amount ofpotassium in our bodies is more than twice the amount ofsodium.- the best known dietary sources of potassium include orangejuice, bananas, breads, cereals and whole grain products.- deficiency in potassium can cause muscle problems feeling ofweakness and increased blood pressure.- excess potassium intake can cause irregular heart beat.
  • 43. MineralsSelenium- mostly functions in the body as seleno-proteins. These act asenzymes to help prevent cell damage in the body fromoxidants produced as byproducts by normal metabolism orthose in the environment.- the best dietary sources for selenium are meats; kidney andliver, seafood and some grains.- deficiency of selenium can adversely affect health. It maycause a fatal heart muscle disease (cardiomyopathy) called“Keshan” disease.- excess intake can cause balding(reversible), brittle nails,intestinal distress, weakness, slowed mental functioning andbreath with a garlic odor.
  • 44. MineralsZinc- involved in the in division of cells and protein manufacture of .It is also part of the hormone insulin.- it aids and improves the sense of taste and that of the smell.- the best dietary sources for zinc are meat, liver, seafood, eggs,whole grains, and nuts.- deficiency in zinc can create a range of health problemsincluding , anemia, gonadal function impairment, difficulty inwound healing, increased skin pigmentation, enlarged spleenand liver, short stature, and immune deficiency- excess intake of this essential mineral can result ingastrointestinal problems and copper deficiency.
  • 45. MineralsChromium- important role in the processing of fats and carbohydrates.- it also assists insulin with glucose uptake and release ofenergy; makes blood sugar, the basic fuel for cells available.- the best dietary sources of chromium include are meats,vegetable oils whole grains, fruits and vegetables.- deficiency in chromium can cause glucose intoleranceimpaired metabolism of fats and amino acids, increased riskof arteriosclerosis, anxiety and fatigue.
  • 46. Fiber- fiber is one kind of carbohydrate. It is sometimes calledroughage or bulk- fiber is the part of plant foods that our bodies do not breakdown during digestion.- because fiber isnt digested, it doesnt give us calories. Foodsthat contain a lot of fiber may also contain other types ofcarbohydrates like starch or sugar.- while we do not get calories from the fiber in these foods, wedo get calories from the sugars and starches they contain.- fiber is important for keeping the digestive tract workingsmoothly. Since we do not digest it, the fiber in food passesinto the intestine and absorbs water.
  • 47. Fiber- the undigested fiber creates "bulk" so the muscles in theintestine can push waste out of the body. Eating enough fiberhelps prevent constipation. It may also reduce the risk ofgetting colon cancer. Some fibers can help lower bloodcholesterol.- dried peas and beans like lentils, black-eyed peas, chickpeasand kidney beans are the best sources of fiber. The skins andseeds in fresh fruits and vegetables are good sources, too.Whole-grain cereals and breads like oatmeal, brown rice, gritsand whole-wheat bread are all naturally high in fiber.- we get more fiber when we eat whole fruits and vegetables
  • 48. Malnutrition- malnutrition is a general term for a medical condition causedby an improper or inadequate diet and nutrition- a number of different nutrition disorders may arise,depending on which nutrients are under or overabundant inthe diet.- there are a number of causes of malnutrition. It may resultfrom inadequate or unbalanced diet, problems with digestionor absorption, certain medical conditions- malnutrition can occur if you do not eat enough food.Starvation is a form of malnutrition.- you may develop malnutrition if you lack of a single vitamin inthe diet.
  • 49. Malnutrition- in some cases, malnutrition is very mild and causes nosymptoms.- however, sometimes it can be so severe that the damagedone to the body is permanent, even though you survive.- malnutrition continues to be a significant problem all over theworld, especially among children.- poverty, natural disasters, political problems, and war allcontribute to conditions - even epidemics of malnutrition andstarvation, and not just in developing countries.