1、營養與食品安全學,一、緒論,（一）定義 是（以營養與食品安全專業知識和技能為手段，以個體或人群為對象）從事營養咨詢、營養測評、營養指導、營養宣教、營養管理以及從事營養教學與科研工作、營養與食品安全知識傳播的特殊職業者，是促進社會公眾健康工作的專業人員。 公共營養師是國家勞動部頒布的第4批新職業之一。是應社會、市場的需要而產生的職業技能人才，指接受專業知識技能培訓，通過國家職業資格考試認證，取得從業資格（勞部發199498號文件第六條規定“勞動部負責以技能為主的職業資格鑒定和證書的核發與管理”），,（二） 需求,1.社會需求 （1）社會環境的變化，需要健康品的人數迅速增加。2006年中國衛生部公

2、布了2005年城鄉居民主要死亡原因，慢性病惡性腫瘤、腦血管病和心臟病為城鄉居民前三位死因 日本東京，來去匆匆的“上班族”中，4個人有3個人都挺著“小肚子”；在臺灣，四分之一的學齡兒童被診斷為“過胖”；中國北京、上海、廣州各大醫院反映：心臟病、中風、糖尿病、腫瘤等發病率呈大幅度上升趨勢；安徽省中醫學院對京、滬、深、港近2萬名25歲以上人士做的調查顯示，年紀越輕，體質越差；一份長達10年的健康調查報告指出，我國中年知識分子的平均壽命僅有5334歲，比72歲的全國人口乎均壽命短了近20歲。,（2）現代醫學模式的轉變 ：世界衛生組織明確提出：下世紀人類健康的65要靠自己。 合理的營養膳食、適當地體力活

3、動、 平和的心理心態、健康的生活方式。 2.職業需求 （1）醫院與社區 （2）其它：學校、餐飲、美容、運動、家庭、個人等。,FOODS食物,NUTRITION 營養 Nutrients, Functional Factor,HEALTH健康,FOOD HYGIENE 食品衛生 Harmful Factors,（It is a science involving natural and social sciences）,緒 論 （PREFACE）,一、 營 養 學 Nutrition,It is a science of foods and the nutrients and other sub

4、stances they contain, and of their actions within the body (including, ingestion, digestion, absorption, metabolism, and excretion).,營養學是從社會、經濟、文化、心理和食物成分等多方面研究膳食、食物和人體健康關系及改善措施的科學。,A broader definition includes the social,economic, cultural, and psychological implications of food and eating.,Delici

5、ous,DEFINITION,（一）定義：,1. CHINA (1) 世界歷史上種植業、養殖業最早和最發達的國家， 形成了以植物性為主的膳食結構 (2) 極為豐富的食品加工技術和加工食品種類 (3) 極早的食物和營養學理論：五谷為養、五果為助、 五畜為益、 五菜為充 (4) 系統的食物、營養與健康關系的認識和理論： 藥食兩用、食補與食療 (5) 豐富的食品資源,2. Modern Nutrition (1) 19世紀：開始對各營養素的認識和研究 (2) 20世紀：主要發現和研究了微量元素 (3) 近代：與其它科學相結合 營養學分支。,（三）歷史 HISTORY,1. 營養素 nutrients

6、 (1) 熱能與健康 (2) 營養素性質與功能：脂肪酸、纖維素、微量營養素、多糖、寡 糖、 酞、氨基酸和核酸等 2. 非營養素 functional factors 酚類(polyphenol)、黃酮(flavone)、甙類(glucoside)等 3. RDA-DRIs 4. 公共營養 Community Nutrition 膳食結構（Dietary Pattern）、膳食指南( - Guide)、膳食心理 ( - Psychology)、營養政策(Nutritional Policy)等 5. 營養與慢性病的發生、發展和預防 (Nutrition and Chronic Disease)

7、6. 學科分類增多 （Branches of Learning）,膳食、營養平衡 (Dietary and Nutritional Balance),（四）進展 PROGRESS,（五）核心 CORE,是研究食品中可能存在的有害人體健康的各類因素、危害性及危害機理和預防措施、管理辦法及相關法律、法規的科學。 It is a science about the harmful factories in the foods , and their harmfulness, mechanisms the preventive measures, management and the laws and

8、 regulations.,（一） DEFINITION,二、食品衛生學 Food Hygiene,（三） HISTORY,1. CHINA (1) 周朝：設“凌人”管理食品冷藏、防腐 (2)唐律：“ 脯肉有毒曾經病人，有余者訴焚之，違者杖 九十；若故與人食，并出賣令人病者徒一年；以故致 死者，絞。” (3)千金翼方： “食魚面腫煩亂，蘆根水解” (4) 科學而系統的食品加工與保藏工藝 2. Modern Food Hygiene (1) 細菌的發現與消毒方法的應用 (2) 有害微生物和相關毒素的發現 (3) 致癌污染物的發現 (4) 相關檢測技術的發展和應用 (5) 法制化：技術、管理與法律

9、,（四）PROGRESS,(1) 老問題不斷出現：口蹄疫，瘋牛病等 (2) 新的問題不斷發現：二惡英、雜環胺、O157、保健食品和 轉基因食品的安全性等 (3) 假冒偽劣食品的鑒別與打擊 (4) 環境污染物和非法使用飼料、食品添加劑等 (5) 法律的不斷完善 (6) 危險性分析、GMP、HACCP等 (7) 經濟全球化，市場、貿易的國際化與貿易壁壘。,以科學為依據，以法律為準繩，以提高食品衛生質量、防止污染和保護人民身體健康為最終目的。,（五） CORE,第一篇 營養學PART 1 NUTRITION,1.營養：是指人體攝取、消化吸收、利用食物中營養物質和排除廢 物的生物學過程。 It is

10、a biological process which nutrients and functional compositions in the foods are ingested, digested, absorbed, transported ,utilized and the waste are excreted.,2.營養素： (1)定義：食物中可給人體提供能量、機體構成成分和組織修復以及有生理調節功能的化學成分。 Chemical substances obtained from food and used in the body to provide energy,structur

11、al materials,and repair of the bodys tissues; Nutrients may also reduce the risk of some diseases.,(2) Classification,protein lipids macronutrients carbohydrate (dietary fiber) nutrients water vitamin micronutrients macroelements minerals microelements,3. 合理營養（Rational Diet） 通過合理的膳食和科學地烹調加工，能向機體提供足夠

12、數量的熱能和各種營養素，并保證各種營養素之間的數量平衡，以滿足人體的正常生理需要，并保持人體健康。 Nutrients intakes meet the requirements of the body,5.膳食營養供給量(Recommended Dietary Allowance，RDA) 是對各種人群提出的保證人體營養需要的膳食中應含有的熱能和營養素的適宜量。 The average daily amount of a nutrient considered adequate to meet the known nutrient needs of practically all healt

13、hy people; a goal for dietary intake by individuals.,4. 營養生理需要量（Nutritional Requirement） 是指能保持人體健康，達到應有發育水平和能充分有效地完成各項體力和腦力活動所需要的熱能和各種營養素的必需量。 The lowest continuing intake of energy and nutrients that maintain the specified criterion of adequacy (that will maintain the specific biochemical and physi

14、ological functions of the body).,Chapter 1 Basic Nutrition 第 一 章 營 養 學 基 礎,含量-16%19%. 更新： 動態平衡，不斷更新，每天約3%，腸和骨髓最快。,Section 1 Protein ( 蛋白質 ),一、蛋白質,（一）人體中蛋白質：,（二）功能：,1.機體構成成分 2.構成各種生理活性物質和重要的生理功能 3.提供熱能,（三）The first structure,蛋白質 (protein),氨基酸 （Amino acid, AA）,非必需AA(nonessential-)：9種 半必需AA（條件必需AA）：2種

15、（semi-,or conditionally-） 必需AA（essentional-）：9種,多肽（poly-）10 AA以上 寡肽（oligo-）410 AA以下 3肽（tri-）3AA 2肽（di-）2AA,肽 (peptide),二、 氨基酸和必需AA( essential amino acid ,EAA),1. 種類：20種 (1) 必需AA（EAA） (2) 非必需氨基酸（NEAA） (3) 半必需氨基酸 ( semi-EAA or conditional EAA) 半胱酸（Cysteine）蛋氨酸（Methionine） 酪氨酸（Tyrosine）苯丙氨酸（Phenylalani

16、ne） 2. 必需氨基酸： 人體不能合成或合成速度不能滿足機體需要，必需從食物中直接獲得的AA。 Amino acids that the body cannot synthesize in amount sufficient to meet physiological needs and has to obtain them from foods.,表 1-1 人體內的氨基酸,*組氨酸為嬰兒必需氨基酸，成人需要量可能較少。 摘自Modern Nutrition in Health and Disease,第9版,第14頁,1999。,(三) 氨基酸模式(AA Pattern)和限制氨基酸 (

17、limiting AA),1. 氨基酸模式 (AA Pattern) ： 蛋白質中各種必需氨基酸的構成比例。,表1-2 幾種食物和人體蛋白質氨基酸模式,數據摘自營養與食品衛生學，第3版，第9頁。,2.限制氨基酸 （limiting amino acid）：,與人體蛋白質模式比較，食物蛋白質中含量相對較 低的必需AA。 The essential amino acid found in the shortest supply relative to the amount needed for protein synthesis in the body. FourAA are mostlikely

18、tobe limiting: Lysine，Methionine，Threonine，Tryptophan .,3.參考蛋白、完全蛋白和蛋白質的互補作用,參 考 蛋 白,用于測定食物蛋白質質量的標準蛋白。 Reference Protein: A standard against which to measure the quality of other proteins.,完 全 蛋 白,必需氨基酸模式與人體蛋白質相對一致，能滿足機體蛋白質合成需要的食物蛋白質。 Complete Protein: A dietary protein containing all the essential

19、amino acids in relatively the same amounts that human being required. (including animal protein and soy protein ) Incomplete protein,蛋 白 質 互 補,將兩種或兩種以上的食物蛋白質混合事用，使不同食物中必需氨基酸以多補少，從而提高膳食蛋白質的營養價值。 Complementary Protein: Two or more proteins whose amino acids assortments complement each other in such a

20、way that the essential amino acids missing from one are supplied by the other.,幾種食物混合后蛋白質的生物價,三、蛋白質的消化、吸收和代謝,（一）消化和吸收 （digestion and absorption）,Gastric Juice : 1. Acid denaturation 2. Pepsin- not highly specific but preferential attack on bonds adjacent to aromatic AA and leucine. 3.Carboxypeptidas

21、e-terminal aromatic or branch-chained; arginine or lysine; neutral-,dietary Protein,Panc- elastase(彈性蛋白酶)- arometic AA reatic trypsin(胰蛋白酶)- NH2- juice chymotrypsine(糜蛋白酶) - lysine, arginine,dipeptide , tripeptide and free AA,absorbed through the mucosal cells of small intestine peptidase,through th

22、ree active free AA transport systems neutral-,basic- and acidic-.,Liver and other organs,（二） 代謝與氮平衡(metabolism and nitrogen balance),1.代謝,攝入蛋白質90克,消 化 道,(30%)肌肉,(50%)器官,體液,其它,機體蛋白質,氨基酸池,糞便10g(1.6gN),尿75g(12gN),其它5g(0.8gN),(20%),腸道內源性蛋白質70g,消化、吸收蛋白質150g,圖1-1 蛋白質代謝及氮平衡,2.氮平衡（Nitrogen balance）,必要的氮損失（o

23、bligatory nitrogen losses） (2) 氮平衡： BI（UFS）,Positive nitrogen balance,N in N out,N in = N out,Nitrogen equillibrium,Negativenitrogen balance,N in N out,四、食物蛋白質營養學評價,(1)真消化率（true -）,(一)蛋白質含量 (content）,(2)表觀消化率（apparent -）:,(二)蛋白質消化率(digestibility),(三)蛋白質利用率（utilization）,1.Biological value, BV:生物價,The

24、 amount of protein nitrogen that is retained for growth and maintenance,expressed as a percentage of the protein nitrogen that has been digested and absorbed. To determine the actual value of an absorbed protein as it is used by the body.,2.Net Protein Utilization,NPU蛋白質凈利用率,The amount of protein ni

25、trogen that is retained from a given amount of protein nitrogen eaten. To determine the amino acid composition and digestibility of a test protein.,3.Protein Efficiency Ratio, PER: 蛋白質功效比值,A measure of protein quality assessed by determining how well a given protein supports weight gain in growing r

26、ats. Used to establish the protein quality for infant formulas and baby foods.,4.Amino Acid Score,AAS氨基酸評分,The lowest score is the score of limiting AA which is the AAS of the protein. A method of evaluating protein quality by comparing a test proteins amino acid pattern with that of a reference pro

27、tein; sometimes called chemical scoring.,表1-4 幾種食物和不同人群需要的氨基酸評分模式,摘自WTO Technical Report Series 724,第12頁,1985年。,表1-5 常見幾種食物蛋白質質量,摘自“營養與食品衛生學”，第3版，第11頁。,5.Protein Digestibility corrected AAS, PDCAAS:（經消化率校正的氨基酸評分）,A measure of protein quality assessed bycomparing the amino acid score of a food protei

28、nWith the amino acid requirements of preschool-ageChildren and then correcting for the truedigestibility of the protein; Recommended by the FAO/WHO and used toestablish protein quality of foods for daily valuepercentage on food labels.,表1-6 幾種食物蛋白質的PDCAAS,摘自Understanding Nutrition, 第7版，第215頁，1996年。,

29、五、蛋白質營養不良（protein-energy malnutrition,PEM）,Kwishiorkor: A Ghanaian word meaning “the evil spirit that infects the first child when the second child is born”. The second child suddenly switched from nutrient dense, protein-rich breast milk to a starchy, protein-poor cereal, soon begins to sicken and

30、die.,Marasmus: A severe deprivation of food over a long time (chronic PEM) and therefore is caused by an inadequate energy and protein intake ( and by inadequate essential fatty acids,vitamins, and minerals as well).,蛋白質營養不良,Kwashiorkor,Marasmus,Marasmus,Kwashiorkor,Infancy(less than 2 yr),older inf

31、ants and young children(1-3 yr),Develops slowly;chronic PEM,rapid onset; acute PEM,Severe weight loss,some weight loss,Severe muscle wasting, with fat,Some muscle wasting,with retention of some body fat,Growth:60% weight-for-age,growth:60%-80% weight-for-age,No detectable edema,edema,No fatty liver,

32、enlarged fatty liver,Anxiety焦急, apathy淡漠,apathy, misery痛苦, irritability易怒, sadness,Good appetite possible,loss of appetite,Hair is sparse,thin and dry; Easily pulled out,hair is dry and brittle; easily pull out; changes color; becomes straight,Skin is dry, thin, and easily wrinkles,skin develops les

33、ion,3. 高蛋白質膳食過多的危害 （problems of excess protein）,Adult Bone Loss (Osteoporosis骨質疏松): Calcium excretion rises as protein intake increases. Recommen-dation of calcium-to-protein is more than 20(mg) to 1(g).,Cancer: population studies suggest a correlation between high intakes of animal protein and some

34、 type cancer ( cancer of colon, breast,kidneys, pancreas, and prostate),Gain Weight: Protein-rich foods are often fat-rich foods. Others.,Heart Disease: Foods rich in animal protein tend tobe rich in saturated fats and cholesterol; homocystei（高半胱氨酸）may be an independent risk factor for heart disease

35、.,六、蛋白質供給量和食物來源 （DRIs and Food source）,RNI: 1) 數量 2）質量 (優質蛋白質) Assessment of protein nutrition in human body (1) Serum albumin: 35-50g/L (2) Serum transferritin: 2.2-4g/L (3) Retinol-binding protein: 26-76mg/L (4) Thyroxine-binding-albumin:280-350mg/L 3. Food Source: animal and plant foods. Milk and

36、 Soy been,中國居民膳食蛋白質的推薦攝入量: RNI與RDA,RNI與RDA：續表,Section 2 Lipids ( 脂類 ),固醇類,sterols：,脂類,甘油三脂, triglycerides：,磷脂, phospholipids,99% in body, 95% in food,99% in body, 95% in food,一、脂類的分類 Classification,一、脂類的功能 (function),Structure：1 glycerol 3 fatty acids Function,（一） triglycerides, 甘油三脂(TG),(1) triglyc

37、erides in the body:,A: Storing and providing the body with energy: 1g 9.46kcal (兩個特點） B: The layer of fat beneath the skin helps keep the body warm ( insulating the body) C: Protecting and propping up the organs in the body D: Helping the body use its two other energy nutrients carbohydrate and prot

38、ein ( sparing protein ) E: The very important composition of the body F: Incretion: leptin, TNF-, IL-6, IL-8, adiponectin, resistin, estrogen, Insulin-like growth factor (IGF), angiotensinogen (血 管緊張素), IGF binding protein 3, plasminogen activator inhibitor (PAI, 纖維蛋白溶酶原激活因子抑制物),(2). Triglycerides i

39、n the foods:,A: Providing body with energy and essential fatty acid. B: Improving the color, flavor, taste and shape of foods. C: Because dietary fat causes the stomach to empty more slowly than either carbohydrate or protein, it imparts satiety and satisfaction. D: To supply body with fat-soluble v

40、itamins and aid intestinal absorption of them.,(3). risk of high-fat diet,Heart disease: Food saturated fat (especially 12, 14, 16 carbons) raises blood cholesterol dramatically, which causes heart attack or stroke. Obesity 肥胖: High-fat diet tend to store body fat efficiently. (3) Cancer: Prostate c

41、ancer is a strong association with fat; Breast cancer is a little or no association with diet fat. (4) Risk from trans-fatty acids: They raise LDL and lower HDL.,(二) fatty acids , 脂肪酸 (FA),chain length: long-chain (1014 carbons or more) medium-chain (6 or 8 -) short-chain ( 24 or 26) Saturation（飽和度）

42、: saturated FA (SFA) monounsaturated FA (MUFA) polyunsaturated FA (PUFA) position of double bond: “n” or “” “n-3”: the initial double bond situated between the third and 4th carbon atoms from the methyl end. “n-6”: the initial double bond is between the 6 and 7 isomeric forms 異構體: cis 順式 ； trans 反式,

43、(1) Classification,(2). Essential fatty acid, 必需脂肪酸 (EFA),Definition:,Classification:,(1) linoleic acid (亞油酸). C 18:2, n-6 (2)- linolenic acid（ 亞麻酸）. C 18:3, n-3,Fatty acids needed by the body , but not made by it to meet physiological needs.,Synthesize of MUFA in body,linoleic acid (C18:2,n-6) -lin

44、olenic acid (C18:3,n-3) 6去飽和酶 -linolenic acid (C18:3,n-6) 十八碳四烯酸 (C18:4,n-3) 碳鏈延長酶 bi-homotype -linolenic 二十碳四烯酸 (C20:4,n-3) acid (C18:3,n-6) 5去飽和酶 arachidic acid (AA) timnodonic acid (EPA) (C20:4,n-6) (C20:5,n-3) 碳鏈延長酶 二十二碳四烯酸 (C22:4,n-6) clupanodonic acid (C22:5,n-3) 4去飽和酶 二十二碳五烯酸 (C22:5,n-6) doco

45、sahexenoic acid (DHA) (C22:5,n-3),Function of EFA,To maintain the structural parts of cell membranes. (it is a part of phospholipids),Used to synthesize many hormone like substances- eicosanoids（二十烷） : prostaglandins (PG,前列腺 素)，Thromboxane(TXA,凝血惡烷)，leukotrienes (LT, 白三烯 ),hydroxy fatty acids, and l

46、ipoxins(脂素).,(3) Lower blood cholesterol and risk of heart attack or stroke, especially EPA (eicosapentaenoic acid) and DHA (docosahaxaenoic acid).,They modulate cardiovascular, pulmonary, immune, reproductive, and secretory functions in many cells.,Deficiency of EFA,Affect development, production,

47、liver, kidney, nerve, vision, and skin.,(三) 磷脂 (phospholipid),1. Structure：,It consist of a glycerol backbone with one or two attached fatty acids, plus a different structure that includes a phosphate group attached to the other hydroxyl group(s).The most important member is lecithins（卵磷脂）.,2. Funct

48、ion,(1) Important constituents of cell membranes. They thus allow fat-soluble substances, including vitamins and hormones, to pass easily in or out of cells. (3) As emulsifiers （乳化劑）in the body or food manufacturers. (4) To supply body with 9 kcalories per gram. (5) Health function: different points

49、.,(四) 固醇 (Sterols),1. Structure:,A same multiple ring with different side groups attached. Cholesterol is the most important.,2. Function:,Essential to the structure and function of cells, especially the cell membrane (about 90% of total body cholesterol ). Cholesterol is the original material for s

50、ynthesis of many vitally important body compounds such as bile, sex hormones, adrenal hormone, and vitamin D.,3. Harmful effects:,It forms deposits (沉積物) in the artery walls which lead to atherosclerosis (動脈粥樣硬化)- a disease that causes heart attacks and strokes.,二、脂類代謝（metabolism）,mouth,salivary gla

51、nd（唾液腺）-lipase（脂肪酶）: It plays a small role in digestion in adults, but efficiently digests the short- and medium-chain fatty acids of milk in infants.,Stomach,Stomachs churning 攪拌 action mixes fat with water and acid . A gastric lipase hydrolyzes a very small amount of fat.,Small intestine,emulsific

52、ation of fat by bile,Pancreatic lipase Intestinal lipase,bile,trapped by dietary fibers and carried out of the body with the feces,Reabsorbed into the blood liver Gallbladder(膽囊),Monoglyceride, fatty acids and glycerol,Long-chain fatty acids Monoglycerides,Glycerol, short- and medium-chain Fatty aci

53、ds absorbed directly into blood,Merge （結合）into micelles (微膠粒),Merge （結合）into micelles (微膠粒),Easily diffuse (擴散) into the intestinal cells and reassembled (重新合成) into new triglycerides.,With cholesterol and phospholipids,Chylomicrons within the intestinal cells,Absorbed into lymph,then into blood Cel

54、ls all over the body remove lipids from the chylomicrons（乳糜微粒） as they pass by, and make them smaller and smaller.,protein,Liver cells collect the chylomicron remnants（殘體）, and pack them with lipids , cholesterol and proteins as VLDL which will travel through the body in the blood.,HDL made in the l

55、iver carry cholesterols and phospholipids from the cells back to the liver.,They lose triglycerides and gather cholesterol from Other lipoproteins circulating through the bloodstream And become LDL,Metabolism of cholesterol,三、 Food source and RDA 脂類的食物來源及供給量,1. Food source:,1). Animal fat: plenty of

56、 SFA,2). Vegetable oil: plenty of MUFA,Linoleic Acid (n-6),leafy vegetables, seeds, nuts, grains, vegetable oil(corn, safflower 紅花, soybean, cottonseed, sesame芝麻, sunflower),Arachidonic Acid (n-6),meats, can be synthesized from linoleic acid,linolenic acid（n-3）,fats and oil ( soybean, walnut胡桃, whea

57、t germ),EPA and DHA (n-3),Human milk, shellfish and fish (mackerel 鮐魚, tuna 金槍魚, salmon大麻哈魚, sturgeon鱘魚, herring鯡魚, trout鱒魚, sardines沙丁魚), can be made from linolenic acid.,2. DRIs: basic principle,percentage of total dietary energy ：20%-30% SFA / total dietary energy 10% n-6 / total dietary energy 3

58、%, n-6n-341 Cholesterol 300mg/d,3. Substitute of fat,蔗糖聚酯 sucrose polyester, Olestra 燕麥素 Ostrim,AIs of dietary fat (percentage of total dietary energy ),注1：SFA為飽和脂肪酸；MUFA為單不飽和脂肪酸；PUFA為多不飽和脂肪酸 注2：n-6/n-3表示n-6系列不飽和脂肪酸與n-3系列不飽和脂肪酸的比例,Section 3. carbohydrate 碳水化合物,一、分類與食物來源 Classification and food source,單糖(monosaccharide) 雙糖(disaccharide) 寡糖(oligosaccharide) 多糖（polysaccharide）,（一）單糖 (monosaccharide),1.Glucose: