Lec 6 consumer nutrition 2


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  • Ellie Whitney and Sharon RadyRolfes; Under standing Nutrition, Twelfth Edition. 2011, 2008 Wadsworth, Cengage Learning
  • Ellie Whitney and Sharon RadyRolfes; Under standing Nutrition, Twelfth Edition. 2011, 2008 Wadsworth, Cengage Learning
  • Ellie Whitney and Sharon RadyRolfes; Under standing Nutrition, Twelfth Edition. 2011, 2008 Wadsworth, Cengage Learning
  • Ellie Whitney and Sharon RadyRolfes; Under standing Nutrition, Twelfth Edition. 2011, 2008 Wadsworth, Cengage Learning
  • Ref. Ellie Whitney and Sharon RadyRolfes; Under standing Nutrition, Twelfth Edition. 2011, 2008 Wadsworth, Cengage Learning
  • Lec 6 consumer nutrition 2

    1. 1. Community and public healthnutrition6-Consumer awareness 2a) Food additivesb) Anti nutrientsPrepared by; Dr. Siham GritlyUniversity of Bahri"All things are poisons; nothing is without poison;only the dose determines whether there is a harmfuleffect“. Paracelsus (16th Century Philosopher)1Dr. Siham Gritly
    2. 2. Glossary• additives: substances not normally consumed as foods butadded to food either intentionally or by accident.• preservatives: antimicrobial agents, antioxidants, and otheradditives that retard spoilage or maintain desiredqualities, such as softness in baked goods.• generally recognized as safe (GRAS): food additives thathave long been in use and are believed to be safe. Firstestablished by the FDA in 1958,• Delaney Clause: a clause in the Food Additive Amendment tothe Food, Drug, and Cosmetic Act that states that no substancethat is known to cause cancer in animals or human beings atany dose level shall be added to foods•2Dr. Siham Gritly
    3. 3. Glossary• margin of safety: when speaking of food additives, azone between the concentration normally used andthat at which a hazard exists. For common tablesalt, for example, the margin of safety is 1/5 (fivetimes the amount normally used would behazardous).• intentional food additives: additives intentionallyadded to foods, such as nutrients, colors, andpreservatives.• indirect or incidental additives: substances thatcan get into food as a result of contact duringgrowing, processing, packaging, storing, cooking, orsome other stage before the foods are consumed; 3Dr. Siham Gritly
    4. 4. Glossary• Nitrites: salts added to food to preventbotulism. One example is sodiumnitrite, which is used to preserve meats.• Nitrosamines; derivatives of nitrites that maybe formed in the stomach when nitritescombine with amines. Nitrosamines arecarcinogenic in animals.• Bacteriophages; viruses that infect bacteriato prevent spoilage.Dr. Siham Gritly 4
    5. 5. Glossary• genotoxicant is a substance that mutates ordamages genetic material• Phytochemicals: nonnutrient compoundsfound in plant-derived foods that havebiological activity in the body.• Antinutrients are natural or syntheticcompounds that interfere with the absorptionof nutrients .• carcinogen is a substance that causes cancer,Dr. Siham Gritly 5
    6. 6. Food additives• Food additives are substances added to foodto preserve flavor or enhance its taste andappearance.• Most additives are preservatives that helpprevent spoilage during the time it takes todeliver foods long distances to grocery storesand then to kitchens.6Dr. Siham Gritly
    7. 7. Some of food additives found in foodDr. Siham Gritly 7
    8. 8. Dr. Siham Gritly 8antimicrobial nitrites and nitratesMonosodiumglutamate MSGEmulsifiers: lecithin, mono- anddiglycerides Gums: agar, alginates(brown algae), carrageenan (extractedfrom red seaweeds), aguar, locustbean,, pectin, xanthan gum, gumarabic, cellulose derivativesArtificial color: indigotine(blue), erythrosine (Food Red), tartrazine(Yellow) Natural: annatto(yellow), caramel (yellowishbrown), carotenoids (yellowishorange), dehydrated beets (reddishbrown), grape skins (red, green)
    9. 9. • Some act as Antimicrobial Agents; The mostwidely used antimicrobial agents are ordinarysalt and sugar.• Salt has been used throughout history topreserve meat and fish;• sugar serves the same purpose in canned andfrozen fruits and in jams and jellies.• Both exert their protective effect primarily bycapturing water and making it unavailable tomicrobes.Dr. Siham Gritly 9
    10. 10. • Other antimicrobial agents, the nitrites, areadded to foods for three main purposes:• to preserve color,• to enhance flavor by inhibitingrancidity, especially in cured meats andpoultry;• to protect against bacterial growthDr. Siham Gritly 10
    11. 11. • Some reduce the risk of foodborne illness (forexample, nitrites used in curing meat preventpoisoning from the botulinum toxin).• Others enhance nutrient quality (as in vitaminD–fortified milk).Dr. Siham Gritly 11
    12. 12. The GRAS (generally recognized as safe)• generally recognized as safe (GRAS), basedeither on their extensive, long-term use infoods or on current scientific evidence.• Several hundred substances are on the GRASlist, including such items assalt, sugar, caffeine, and many spices.Dr. Siham Gritly 12
    13. 13. The Delaney Clause• a clause in the Food Additive Amendment tothe Food, Drug, and Cosmetic Act that statesno substance that is known to cause cancer inanimals or human beings at any dose levelshall be added to foodsDr. Siham Gritly 13
    14. 14. • the FDA prefers to believe additives (andpesticides and other contaminants) safe iflifetime use presents no more than a one-in-a-million risk of cancer to human beings.• Thus, instead of the “zero-risk” policy of theDelaney Clause, the FDA uses a “negligible-risk” standard,Dr. Siham Gritly 14
    15. 15. Margin of Safety• To determine risks of an additive, researchersfeed test animals the additive at severalconcentrations throughout their lives.• The additive is then permitted in foods inamounts 100 times below the lowest level thatis found to cause any harmful effect, that is, ata 1/100 margin of safety.Dr. Siham Gritly 15
    16. 16. Risks versus Benefits• additives would not be added to foods if theyonly presented risks.• general, additives are used in foods when theyoffer benefits• in the case of color additives only enhanceappearance but do not improve health orsafetyDr. Siham Gritly 16
    17. 17. • the FDA finds it worth taking the small risksassociated with the use of nitrites on meatproducts, for example, because nitrites inhibitthe formation of the deadly botulinum toxin.Dr. Siham Gritly 17
    18. 18. Benefit of food additivesWithout additives, bread would quickly getmoldy, and salad dressing would go rancidDr. Siham Gritly 18Ref. Ellie Whitney and SharonRady Rolfes; Under standingNutrition, Twelfth Edition. 2011,2008 Wadsworth, CengageLearning
    19. 19. • The FDA also requires that additives not beused:• To disguise faulty or inferior products• To deceive the consumer• When they significantly destroy nutrients• When their effects can be achieved byeconomical, sound manufacturing processesDr. Siham Gritly 19
    20. 20. Intentional Food Additives• Intentional food additives are added to foodsto give them some desirable characteristic:• resistance to spoilage,• color, flavor, texture,• stability,• nutritional value.20Dr. Siham Gritly
    21. 21. Intentional Food AdditivesEllie Whitney and Sharon Rady Rolfes; Under standing Nutrition, Twelfth Edition.2011, 2008 Wadsworth, Cengage LearningFood Additive Purpose Common ExamplesAntimicrobial agents)Preventmicroorganismsfrom growingSalt, sugar, nitrites andnitrates (such as sodiumnitrateAntioxidants Delay or preventrancidity of fatsand other damageto foods caused byoxygenVitamin C (ascorbic acid, sodiumascorbate), vitamin E(tocopherol), sulfites, syntheticantioxidants butylhydroxyanisole(BHA) and butylhydroxytoluene(BHT)21Dr. Siham Gritly
    22. 22. Intentional Food AdditivesEllie Whitney and Sharon Rady Rolfes; Under standing Nutrition, Twelfth Edition. 2011, 2008Wadsworth, Cengage LearningColors EnhanceappearanceArtificial: indigotine (blue),erythrosine (red), tartrazineYellowNatural: annatto (yellow), caramel(yellowish brown), carotenoids(yellowish orange), dehydrated beets(reddish brown), grape skins (red,green)Flavors Enhance taste Salt, sugar, spices, artificialsweeteners, MSG(Monosodiumglutamate)Dr. Siham Gritly 22
    23. 23. Intentional Food AdditivesFood Additive Purpose Common ExamplesEmulsifiers andgumsThicken,stabilize, orotherwiseimprove theconsistencyEmulsifiers: lecithin, mono- anddiglycerides Gums: agar,alginates (brown algae),carrageenan(extracted from redseaweeds), locust bean, psyllium,pectin, xanthan gum, gum arabic,cellulose derivativesNutrients(vitaminsandminerals)Improve thenutritivevalueThiamin, niacin, riboflavin, folate, iron(in grain products); iodine (in salt);vitamins A and D (in milk); vitamin Cand calcium (in fruit drinks); vitaminB12(in vegetarian foods)23Dr. Siham Gritly
    24. 24. Natural food coloring: annatto (yellowDr. Siham Gritly 24
    25. 25. Psyllium and psyllium seedsDr. Siham Gritly 25the combination of low fatdiet, low in saturated fats andcholesterol plus psyllium, canreduce total cholesterol levels by4% and low density lipoprotein(LDL) cholesterol by 7%. Thesoluble fiber in psyllium reducesabsorption of blood cholesterol andbile acids from the intestine andthat in turn lowers bloodcholesterol levels.
    26. 26. Gum ArabicDr. Siham Gritly 26
    27. 27. Indirect Food Additives• Indirect or incidental additives find their wayinto foods during harvesting, production,processing, storage, or packaging.• Incidental additives may include tiny bits ofplastic, glass, paper, tin, and other substancesfrom packages as well as chemicals fromprocessing, such as the solvent used todecaffeinate coffee.Dr. Siham Gritly 27
    28. 28. Example of Indirect or incidental additivesRef WHO 2013• Acrylamide (C3H3ONH2) is a chemical that isproduced naturally in certain foods when they arecooked at high temperatures.• It is also manufactured industrially for use in theproduction of polyacrylamide gels, which areused for various purposes, including the treatmentof drinking-water and wastewater.• Acrylamide is known to cause cancer in animalsand, in high doses, can cause nerve damage inhumans.Dr. Siham Gritly 28
    29. 29. • Acrylamide; compound that forms whencarbohydrate-rich foods containing sugars andthe amino acid asparagine are cooked at hightemperatures• Common foods containing acrylamide:• French fries• Potato chips• Breakfast cereals• CookiesDr. Siham Gritly 29
    30. 30. • Food Packaging• The FDA ensures the safety of foodpackaging and assesses whether packagingmaterials might migrate into foods.• These materials, known as ―food contactsubstances,‖ include coatings on caninteriors, plastics, papers, and sealants.Dr. Siham Gritly 30
    31. 31. • Dioxins• dioxins is a class of chemical pollutants createdas by-products of chemical manufacturing,burning, chlorine bleaching of paper pulp, andother industrial processes.• Scientists suggested that dioxins are extremelytoxic and are likely to cause cancer in humans• Dioxins persist in the environment andaccumulate in the food chainDr. Siham Gritly 31
    32. 32. • Examples; Coffee filters, milk cartons, paperplates, and frozen food packages, if madefrom bleached paper,• Human exposure to dioxins comes primarilyfrom foods such as beef, milkproducts, pork, fish, and shellfishDr. Siham Gritly 32
    33. 33. • Decaffeinated Coffee Many consumers havetried to eliminate caffeine from their diets byselecting decaffeinated coffee.• To remove caffeine from coffeebeans, manufacturers often use methylenechloride in a process that leaves traces of thechemical in the final product.• People are exposed to much more methylenechloride from other sources such as hair spraysand paint-stripping solutions.Dr. Siham Gritly 33
    34. 34. • Hormones are a unique type of incidentaladditive in that their use is intentional, buttheir presence in the final food product is not.• The FDA has approved about a dozenhormones for use in food-producing animals,• hormone treated animals produce leanermeats, and dairy cows produce more milk.Dr. Siham Gritly 34
    35. 35. • Antibiotics Like hormones, antibiotics are alsointentionally given to livestock, and residuesmay remain in the meats and milks.• people consuming these foods receive tiny dosesof antibiotics regularly, and those with sensitivityto antibiotics may suffer allergic reactions.• To minimize drug residues in foods, the FDArequires a specified time between the time ofmedication and the time of slaughter to allow fordrug metabolism and excretion.Dr. Siham Gritly 35
    36. 36. Natural Toxicants in Foods• Plants may serve as poisons; forexample, hemlock, a member of the parsleyfamily, has been known as a deadly poison.• Most chemicals that are natural poisonsproduced by the plant forms part of its defensemechanism against herbivores and pathogens.Dr. Siham Gritly 36
    37. 37. • A system within cells (p-glycoproteins), foundespecially in the mucosa of the gastrointestinaltract (esophagus, stomach and colon), protectsagainst toxic substances in plants, bacteria andfungi• Natural toxicants include the goitrogens incabbage, cyanogens in lima beans, andsolanine in potatoes and others37Dr. Siham Gritly
    38. 38. Goitrogens• Poisonous mushrooms are a familiar exampleof plants that can be harmful when eaten.• Cabbage, turnips , mustardgreens, , brussels sproutscauliflower , broccoli, kohlrabi, and radishes contain small quantities ofgoitrogens—compounds that can enlarge thethyroid gland38Dr. Siham Gritly
    39. 39. GoitrogensDr. Siham Gritly 39Cabbage,turnipscauliflowerbrussels sproutskohlrabimushroomsradishes
    40. 40. Cyanogens• Cyanogens inactive compounds that producethe deadly poison cyanide upon activation by aspecific plant enzyme.• Lima beans, cassava and fruit seeds such asapricot pits contain cyanogens40Dr. Siham Gritly
    41. 41. CyanogensDr. Siham Gritly 41Lima beansapricot pitscassava
    42. 42. • Dozen of seeds if eaten can be fatal to a smallchild.• the most infamous cyanogen in seeds islaetrile; a compound mistakenly representedas a cancer cure.• laetrile kills cancer, but only at doses that killthe person, too.Dr. Siham Gritly 42
    43. 43. Solanine; Average solanine content: 8 mg/100 gpotato. Toxic solanine dose: 20 to 25 mg/100 gpotato• potato contains many natural poisons includingsolanine, a powerful narcotic-like substance.• Most of a potato’s solanine is found in the sprout andin the green layer that develops just beneath the skin.• Solanine poisoning is extremelyrare, however, because the small amounts of solaninenormally found in potatoes are harmless—even whenthe potato skin is eaten. Solanine can be toxic, whenconsumed in large quantities.Dr. Siham Gritly 43
    44. 44. • Cooking does not destroy solanine, but it canbe removed by peeling the potato.• Found also in apples, egg plants, roots andleaves of tomatoes and sugar beet roots• Symptoms of solanine poisoning includegastrointestinal disturbances and neurologicaldisorders.Dr. Siham Gritly 44
    45. 45. • Hormone disrupters are chemicals that affecthuman or animal health by interfering withnormal hormonal processes• Example; Oestrogens: at least 50 plants areknown to contain chemicals that haveoestrogenic activity, including carrots, soya beans,wheat, rice, oats, barley , potatoes, apples,cherries, plums and wheat germ.• Oestrogens are also present in vegetable oils suchas cotton seed, sunflower, corn, linseed, olive andcoconut oils.Dr. Siham Gritly 45
    46. 46. • Gossypol: this is the yellow colouring ofcotton, Gossypium.• When ingested, the results are depressedappetite and loss of body weight, cardiacirregularity and circulatory failure orpulmonary oedema.• A major source of gossypol in the diet iscotton seed oil, which may be found in saladoil, margarine and shortening.Dr. Siham Gritly 46
    47. 47. Dr. Siham Gritly 47Gossypolcotton seed
    48. 48. • Myristicin: hallucinogenic chemicalproduced by, celery, parsley, parsnip, mint andnutmeg.• It is said that as little as 500 mg of raw nutmegmay produce psychoactive symptoms,• while 5–15 mg of powdered nutmeg mayresult in euphoria, hallucinations and a dream-like feeling, followed by abdominalpain, depression and stupor (coma)Dr. Siham Gritly 48
    49. 49. Dr. Siham Gritly 49celery,parsleyparsnipmint
    50. 50. CarcinogensA carcinogen is a substance that causes cancer, and agenotoxicant is a substance that mutates or damages geneticmaterial• Safrole is a carcinogen found in severaloils, including oil of sassafras, camphor andnutmeg.• Safrole has been found in 53 plant species and inten plant families, and has been shown to produceliver cancer when sufficient is added to a rat diet.• Black pepper contains small amounts of safroleand larger amounts of piprine, which has beenshown to be carcinogenic to mice.50Dr. Siham Gritly
    51. 51. Dr. Siham Gritly 51sassafras, camphornutmeg
    52. 52. • Furanocoumarins are carcinogenic chemicalsproduced by celery, parsley and parsnip. Theconcentration in these plants is low, but mayincrease in diseased plants.• Cycasin is found in cycads, which are importantsources of starch for tropical and subtropicalpopulations. Such compounds can produceliver, kidney, intestinal and lung cancers in rats.52Dr. Siham Gritly
    53. 53. • Mutagens: the cooking and processing ofmeat and fish at high temperatures results inheterocyclic amines with mutagenic andcarcinogenic effect53Dr. Siham Gritly
    54. 54. • Epichloro-hydrin Carcinogens in tea bags• Some tea bags are made using a wet paperstrength reinforcing coating usingepichlorohydrin, which is known to becarcinogenic.• epichlorohydrin found also in coffee filters,sausage/salami casings have the same issues.• use loose leaf tea or make sure the tea bagsdont use epichlorohydrinDr. Siham Gritly 54
    55. 55. Anti-nutrientsDr. Siham Gritly 55Anti-nutrients are,compounds which preventthe nutritive value of foodsfrom being effective, either;by preventing theabsorption of nutrients,Or by being toxicthemselves,
    56. 56. Phytate and oxalatesand their interfering with nutrients• Oxalates and phytates belong to a group of anti-nutrients.• phytates has a strong binding affinity to mineralssuch calcium, magnesium, iron, copper and zinc• This results in precipitation, making the mineralsunavailable for absorption in the intestines.• Phytic acids are common in the nuts, seeds andgrains56Dr. Siham Gritly
    57. 57. • Oxalates have an adverse effect of binding toessential minerals like calcium, magnesiom andiron• oxalic acid presents in many plants, particularlyin members of the spinach family. Oxalates bindto calcium and prevent its absorption in thehuman body• accumulate in body tissues, causes toxicity overtime• They also bind to calcium to form calciumoxalate, which can then easily settle out assediments from the urine, causing kidney stones.57Dr. Siham Gritly
    58. 58. short list of high oxalate foodsDr. Siham Gritly 58Swiss ChardSpinachPlantainsAlmondsCashewsSesame Seeds
    59. 59. Summary of Some of anti-nutrients compound and theireffectsAntinutrient Source of food Activities in the bodyPhytate and oxalicacidspinach, broccoli inhibits mineral absorptionFlavonoidstanninstea, coffee, winereduce the absorption ofiron and zincinhibits mineral absorptionProtein, trypsininhibitors andLectinsbeans, wheat, CastorBeansinhibits digestive enzymesglucosinolatesbroccoli, brussel sprouts,cabbage and cauliflower.prevent the uptake ofiodine , affecting thefunction of the thyroid andthus are consideredgoitrogensDr. Siham Gritly 59
    60. 60. Reduce phytates and oxalates effectsBoiling and then discarding the water, or soaking anddiscarding the soaking water, can help reduce bothphytates and oxalatesother traditional methods of food preparation such asfermentation, cooking, malting reducing certainantinutrientsDr. Siham Gritly 60broccolispinach
    61. 61. • 1997-2012 HealthCheck Systems• Sareen Gropper, Jack Smith and James Groff, Advanced Nutrition and HumanMetabolism, fifth ed. WADSWORTH• Melvin H Williams 2010; Nutrition for Health, Fitness and Sport. 9th ed, McGrawHill•• Heymsfield, SB.; Baumgartner N.; Richard and Sheau-Fang P. 1999. ModernNutrition in Health and Disease; Shils E Maurice, Olson A. James, ShikeMoshe and Ross A. Catharine eds. 9th edition• Guyton, C. Arthur. 1985. Textbook of Medical Physiology. 6th edition, W.B.Company• FAO/WHO/UNU expert consultation (WHO, 1985) report• Ellie Whitney and Sharon Rady Rolfes; Under standing Nutrition, Twelfth Edition.2011, 2008 Wadsworth, Cengage Learning61Dr. Siham Gritly
    62. 62. • Health implications of acrylamide in food.Joint FAO/WHOconsultation, Geneva, Switzerland, 25 - 27June 2002Dr. Siham Gritly 62
    63. 63. • parsley• , camphor and nutmeg• by celery, parsleyand parsnip• , cherries, plums• , linseed• sassafras• locust beanDr. Siham Gritly 63