Animal Plant Food Lipids “Fats&Oils” ·Introduction Lipids Major lipid components Working definition: ·Minor components Organic compounds(CHO)that do ·Dietary fats ·Processing not mix with Water Chemical properties Lipid oxidation and antioxidants We will use the term lipids“mostly” ·Health effects Effect of Lipid Composition and Processing on Functionality of Foods Food Caloric Values MAJOR COMPONENTS EFFECTS/FUNCTIONS SPECIFICS QUALITY ATTRIBUTES Color,Flavor Texture Sensory properties .Nutritionists use the term Calorie(big C)to imply keal COPROCONO I Kilocalorie (kcal)=I Calorie=1000 calories FUNCTIONALITY .In Europe-joules(welcome to the metric system!) ESSENTIAL NUTRIENTS ·4.2 joules=I calorie NUTRITIVE VALUE or 4.2 Kilojoules (kj)=I kcal =1 Cal
1 Animal & Plant Fats & Oils Lipids Working definition: Organic compounds (CHO) that do not mix with Water We will use the term lipids mostly Food Lipids • Introduction • Major lipid components • Minor components • Dietary fats • Processing • Chemical properties • Lipid oxidation and antioxidants • Health effects Effect of Lipid Composition and Processing on Functionality of Foods MAJOR COMPONENTS EFFECTS/FUNCTIONS SPECIFICS Color, Flavor Texture QUALITY ATTRIBUTES FUNCTIONALITY APPLICATIONS Shortenings, Margarine Spreads, Emulsions Structured lipids Confectionary products NUTRITIVE VALUE ESSENTIAL NUTRIENTS Linoleic acid, Linolenic acid, Long –chain PUFA Vitamins: A, D, E, K Antioxidants COMPOSITION AND PROCESSING Affect Affect Chemical and physical properties Sensory properties Food Caloric Values • Nutritionists use the term Calorie (big C) to imply kcal • 1 Kilocalorie (kcal) = 1 Calorie = 1000 calories • In Europe - joules ( welcome to the metric system!) • 4.2 joules = 1 calorie or 4.2 Kilojoules (kj) = 1 kcal = 1 Cal
Caloric Values Recommendations for Fat (fats and Carbohydrates 4 kcals/gram oils)Intake Proteins 4 kcals/gram Recommendations of the USDADietary Guidelines for Lipids 9 kcals/gram Americans"ref:fats So we can say that Lipids have twice the amount of Kcalories as Carbohydrates*or -Eat less than 30%of total Proteins. calories from fats and oils *digestible carbohydrates 2010 US Dietary Guidelines An example of 'low fat'hotdogs I+3%% ·3%fat(by weight) 进日 ·20%of calories 97%FAT free from fat Beef Frankfurters
2 Carbohydrates 4 kcals/gram Proteins 4 kcals/gram Lipids 9 kcals/gram So we can say that Lipids have twice the amount of Kcalories as Carbohydrates* or Proteins. *digestible carbohydrates Caloric Values Recommendations for Fat (fats and oils) Intake • Recommendations of the USDADietary Guidelines for Americans ref: fats –Choose a diet low in fat, saturated fat, and cholesterol –Eat less than 30% of total calories from fats and oils 2010 US Dietary Guidelines Limit your intake of Empty Calories. Empty Calories are from food components such as added sugars and solid fats that provide little nutritional value. Empty Calories are part of Total Calories. An example of low fat hotdogs • 3% fat (by weight) • 20% of calories from fat
Lipid Content of Some Foods With high water content. Foods g lipid per 100 g food Gampbelh Hearry Chicken Vegerable chicken 3.4 milk 3.5 Healthy Request. pizza 8.3 eggs 11.5 Hearty chicken vecetable hamburger 20.3 cheese(processed) potato chips 39.8 steak 42.2 mayonnaise 79.9 margarine/butter 81.0 USDA Agricultural Handbook No.8 Consumption of Fats History Approximately 80 to 140 grams per day made up of visible and invisible fats An vegetable oil is a triglyceride extracted from a plant.Such oils have been part of Visible fats (60+grams): human culture for millennia. frying fats,shortenings,vegetable salad oils butter,lard Although many plant parts may yield oil in commercial practice,edible oil is extracted Invisible fats(80 grams):lipid components of primarily from seeds. foods:meat,chicken,turkey,fish,bread,milk and dairy products,potato chips,donuts
3 With high water content . Foods g lipid per 100 g food beer 0.0 bread 3.2 chicken 3.4 milk 3.5 pizza 8.3 eggs 11.5 hamburger 20.3 cheese (processed) 30.0 potato chips 39.8 steak 42.2 mayonnaise 79.9 margarine/butter 81.0 USDA Agricultural Handbook No. 8 Lipid Content of Some Foods Consumption of Fats • Approximately 80 to 140 grams per day made up of visible and invisible fats • Visible fats (60+ grams): frying fats, shortenings, vegetable salad oils, butter, lard • Invisible fats (80 grams): lipid components of foods: meat, chicken, turkey, fish, bread, milk and dairy products, potato chips, donuts History • An vegetable oil is a triglyceride extracted from a plant. Such oils have been part of human culture for millennia. • Although many plant parts may yield oil in commercial practice, edible oil is extracted primarily from seeds
World production Oil Production Palm oil is the largest in .Mechanical extraction"crushing"or"pressing" quantity of all vegetable oils Older method used to produce the more traditional oils(e.g,olive and palm) Soybean oil is the largest in quantity ·Solvent extraction The most common solvent is petroleum-derived hexane. 4This technique is used for most of the "newer" MILD TECHNOLOGY, NATURALLY. Virgin The word“virgin”used by the legislation to Because a fruit is rich in water,its oil can be extracted describe olive oil means precisely this: by purely mechanical means. "That the oil has been extracted from the olives using purely mechanical means." After crushing of the fruit,water and oil can also be easily separated by centrifugation
4 World production • Palm oil is the largest in quantity of all vegetable oils. • Soybean oil is the largest in quantity of all edible vegetable oils. 13 Oil Production • Mechanical extraction "crushing" or "pressing” Older method used to produce the more traditional oils (e.g., olive and palm) • Solvent extraction The most common solvent is petroleum-derived hexane. This technique is used for most of the "newer" industrial oils such as soybean and corn oils. 14 MILD TECHNOLOGY, NATURALLY. Because a fruit is rich in water, its oil can be extracted by purely mechanical means. After crushing of the fruit, water and oil can also be easily separated by centrifugation. Virgin The word virgin used by the legislation to describe olive oil means precisely this: That the oil has been extracted from the olives using purely mechanical means.
Oil Refining Animal Fats Animal fats and oils are lipid materials Today most food oils are derived from animals. "refined"that is separated fron Physically,oils are liquid at room organic solvents (Chemical Means). temperature,and fats are solid. The solvents are then boiled away leaving the oil and Chemically,both fats and oils are composed other plant compounds behind. of triglycerides. .The separation of fat from animal tissue is The solvents can be reused. scalled rendering. Functions of Fats CLASSES OF FATS OILS Health aspects Concentrated sources of calories(9 Kcal/g). Provide 30 to 40%of calories of U.S.diet. There is great interest in modification of lipid content and composition.However,fats do more than provide calories Physical and chemical functions: Impact on taste and texture.These properties must be simulated in low-fat foods. ·Satiety:“ful”or“stuffed”feeling
5 17 Oil Refining • Today most food oils are refined” that is separated from the plant seeds with organic solvents (Chemical Means). • The solvents are then boiled away leaving the oil and other plant compounds behind. • The solvents can be reused. Animal Fats • Animal fats and oils are lipid materials derived from animals. • Physically, oils are liquid at room temperature, and fats are solid. • Chemically, both fats and oils are composed of triglycerides. • The separation of fat from animal tissue is 18 called rendering. Functions of Fats • Health aspects: Concentrated sources of calories (9 Kcal/g). Provide 30 to 40 % of calories of U.S. diet. There is great interest in modification of lipid content and composition. However, fats do more than provide calories. • Physical and chemical functions: Impact on taste and texture. These properties must be simulated in low-fat foods. • Satiety: full or stuffed feeling.
Functions of Fats Flavor:source of desirable and undesirable flavors desirable flavors:from lactones and diacetyl in butter,ketones in cheese. undesirable flavors:rancid,tallowy and fishy flavors.2,4-decadienal:at low levels provides desirable fried food flavor to potato chips,but at high levels imparts undesirable rancid flavors Color:sheen impact from waxes,yellow color from carotenoids,green from chlorophylls Texture:mouth feel in butter and margarine, smooth feel of milk and ice cream Roles of Fats ·Energy source ·Texture -Adipose tissue ·E.g.Marbling of meat ·USDA grading is based on fat distribution
6 Functions of Fats • Flavor: source of desirable and undesirable flavors desirable flavors: from lactones and diacetyl in butter, ketones in cheese. undesirable flavors: rancid, tallowy and fishy flavors. 2,4-decadienal: at low levels provides desirable fried food flavor to potato chips, but at high levels imparts undesirable rancid flavors. • Color:: sheen impact from waxes, yellow color from carotenoids, green from chlorophylls • Texture: mouth feel in butter and margarine, smooth feel of milk and ice cream Roles of Fats • Energy source • Texture – Adipose tissue • E.g. Marbling of meat • USDA grading is based on fat distribution Prime Choice Select Standard Utility Cutter
Lipids Major lipid components The building blocks ·Fatty acids Triacylglycerols(triglycerides) glycerol Phosphoglycerides(phospholipids) fat的y acids ·Minor components HO Hydrocarbons,Sterols,Tocopherols,Carotenoids Dietary fats Essential fatty acids,Eicosanoids, Biological functions Triglyceride or Fatty Acid Structure Triacylglycerols R-groups on fatty acid chains are generally linear hydrocarbons,e.g. triglyceride O.C CE CIC CIC which may be more simply represented as
7 Lipids • Major lipid components • Fatty acids • Triacylglycerols (triglycerides) • Phosphoglycerides (phospholipids) • Minor components • Hydrocarbons, Sterols, Tocopherols, Carotenoids • Dietary fats • Essential fatty acids, Eicosanoids, Biological functions The building blocks OH OH OH Triglyceride or Triacylglycerols Fatty Acid Structure • R-groups on fatty acid chains are generally linear hydrocarbons, e.g. which may be more simply represented as C O - O - CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH3 CH2 CH2 CH2 CH2 CH2 CH2 CH2 C O - O -
Numbering Schemes Fatty Acid Chain Representation often number carbons from the opposite(tail)end ·The symbol△followed by the carbn number is -this nomenclature uses w to denote the double bond position used to indicate the position of the double bond E.g.the molecule E.g.18:1△9 o8入人人人又 o入人人人。 can be designated as 18:3 A9,12,15,or as 18:3 03,6.9. consists of 18 carbons with I double bond located between the 9th and 10th carbon. 0- 又及只贝一及一及一人 1816141210976143 Important Food Fatty Acid Constituents Systematic Names Co Name Prefix indicates number of carbons .Suffix indicates degree of unsaturation -“-anoic'”ifsaturated -“-enoic”if monounsaturated -“-adienoic”if two double bonds ,2 -"atrienoic"if three double bonds -“-atetraenoic”if four double bonds
8 Fatty Acid Chain Representation • The symbol Δ followed by the carbon number is used to indicate the position of the double bond E.g. 18:1Δ9 consists of 18 carbons with 1 double bond located between the 9th and 10th carbon. 12 14 16 18 11 13 15 17 1 3 5 7 9 10 2 4 6 8 C O - O - Numbering Schemes • Scientists in the medical and nutrition community often number carbons from the opposite (tail) end – this nomenclature uses ω to denote the double bond position E.g. the molecule can be designated as 18:3 Δ9,12,15, or as 18:3 ω3,6,9. 12 18 14 16 11 13 15 17 10 C O - O - 1 2 3 4 5 6 7 8 9 18 16 14 12 17 15 13 11 10 C O - O - 1 2 4 3 5 7 6 8 9 Systematic Names • Prefix indicates number of carbons • Suffix indicates degree of unsaturation – -anoic if saturated – -enoic if monounsaturated – -adienoic if two double bonds – -atrienoic if three double bonds – -atetraenoic if four double bonds Important Food Fatty Acid Constituents Abbreviation Systematic Name Common Name Symbol 4:0 Butanoic Butyric B 6:0 Hexanoic Caproic H 8:0 Octanoic Caprylic Oc 10:0 Decanoic Capric D 12:0 Dodecanoic Lauric La 14:0 Tetradecanoic Myristic M 16:0 Hexadecanoic Palmitic P 18:0 Octadecanoic Stearic St 18:1 9-Octadecenoic Oleic O 18:2 9,12-Octadecadienoic Linoleic L 18:3 9,12,15-Octadecatrienoic Linolenic Ln 20:0 Eicosanoic Arachadic A 20:4 5,8,11,14-Eicosatetraenoic Arachadonic An 22:1 13-Docosenoic Erucic E Δ9,12
SATURATED AND UNSATURATED FATTY ACIDS Food Fatty Acid Constituents 入入入入入入入入00 ·Most food fatty acids -Even number of carbons Oleic acid:cis-octadecenoic acld(1:n-) -Linear (not branched) 人人-入-入入入√入 .Even though tr noletcacltcsg.ctst2octadecadienoicacidt:2n-6 Erucic acid found naturally in brassicus rapus (rape seed) Linolenic acid:cis-9.cis-12,cis-15-octadecstrienolc acid (1:n3) -Modem cultivar developed with low levels of erucic acid Canola oil citc6,cis,cis1,cis14ocosaietra8nolcacdf2o4n6 POLYUNSATURATED FATTY ACIDS 人入-入入入入 Fatty Acid Structure Linololc acld:cs8c12-octadecadono acd(:) -0 0 入入=入-入入√入√入 Linolenic acid:cis-3.cis-12.cls-15-octadecatrienoic acid :3n-) 入一入一入一入一入一入入c洲 ontaonolc acld:20:5 n-3 (EPA) (a) (b)
9 Food Fatty Acid Constituents • Most food fatty acids – Even number of carbons – Linear (not branched) – Double bonds in nature are cis • Even though trans double bonds are in lower energy state • Erucic acid found naturally in brassicus rapus (rape seed) – Modern cultivar developed with low levels of erucic acid • Canola oil SATURATED AND UNSATURATED FATTY ACIDS COOH Stearic acid: octadecanoic acid (18:0) COOH Linoleic acid: cis-9,cis-12-octadecadienoic acid (18:2 n-6) COOH Oleic acid: cis-9-octadecenoic acid (18:1 n-9) COOH Linolenic acid: cis-9,cis-12,cis-15-octadecatrienoic acid (18:3 n-3) COOH Arachidonic acid: cis-5,cis-8,cis-11,cis-14-eicosatetraenoic acid (20:4 n-6) POLYUNSATURATED FATTY ACIDS COOH Linoleic acid: cis-9,cis-12-octadecadienoic acid (18:2 n-6) COOH Linolenic acid: cis-9,cis-12,cis-15-octadecatrienoic acid (18:3 n-3) COOH Arachidonic acid: cis-5,cis-8,cis-11,cis-14-eicosatetraenoic acid (20:4 n-6) COOH Eicosapentaenoic acid:20:5 n-3 (EPA) COOH Docosahexaenoic acid: 22:6 n-3 (DHA)
Properties of Fatty Acids Saturated fatty acids have high melting points~65C(fat) Mono-Unsaturated fatty have low M.P.'s~10C (oil) Poly-Unsaturated fatty acids have even lower M.P.'s~-10C (oil) Mixture of saturated and Trans-fatty acids have moderate melting points~45C(fat) Saturated fatty acids unsaturated fatty acids (more like saturated fatty acids) (c) (d Saturated and Unsaturated Average Fatty Acid Composition of Fats Oils (%yw叫 Fatty acids Fats 16:018:018:118:2183 Soybean 11 2 53 Canola 2 56 10 Sunflower 6 trace Corn 13 5322 3 1 Olive 1 Cottonseed 27 18 1 trace Palm 44 0 trace Lard 27 11 44 others Tallow 27 8 others trans poly-unsaturated
10 Properties of Fatty Acids Saturated fatty acids have high melting points ~65°C (fat) Mono-Unsaturated fatty have low M.P.s ~ 10°C (oil) Poly-Unsaturated fatty acids have even lower M.P.s ~ -10°C (oil) Trans-fatty acids have moderate melting points ~ 45°C (fat) (more like saturated fatty acids) Saturated and Unsaturated Fatty acids Fats 16:0 18:0 18:1 18:2 18:3 Soybean 11 4 22 53 8 Canola 4 2 56 26 10 Sunflower 6 5 20 69 trace Corn 13 3 31 52 1 Olive 10 2 78 7 1 Cottonseed 27 2 18 51 trace Palm 44 4 40 10 trace Lard 27 11 44 11 others Tallow 27 7 48 2 others Average Fatty Acid Composition of Fats & Oils (% by wt)