Fats

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FatsFats

Foods that are mostly fatFoods that are mostly fat

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TrendsTrends

Total fat consumption in 2000 was 82.3 lb per Total fat consumption in 2000 was 82.3 lb per capita. Total fat consumption in 2004 was 87.5 capita. Total fat consumption in 2004 was 87.5 lb per lb per Between 2000 and 2004, salad, cooking, and Between 2000 and 2004, salad, cooking, and other edible oils has increased from 34.8 to 40.8 other edible oils has increased from 34.8 to 40.8 lb per capita. Butter and margarine lb per capita. Butter and margarine consumption has decreased from 12 lb to 9.9 lb consumption has decreased from 12 lb to 9.9 lb per per In 2004, soybean oil accounted for 87% of all oil In 2004, soybean oil accounted for 87% of all oil production in the US.production in the US.

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SourcesSources

Animal-beef tallow, butter fat (milk), lard from Animal-beef tallow, butter fat (milk), lard from pigspigs

Vegetable-olives, palm berries and palm Vegetable-olives, palm berries and palm kernels, cottonseeds, soybeans, rapeseed kernels, cottonseeds, soybeans, rapeseed (canola oil), corn, sunflower seeds, safflower (canola oil), corn, sunflower seeds, safflower seeds, coconuts, peanuts, cocoa beans, seeds, coconuts, peanuts, cocoa beans, walnuts, macadamia nuts, rice branwalnuts, macadamia nuts, rice bran

Fish oils-decosahexanoic acid (DHA) and Fish oils-decosahexanoic acid (DHA) and eicosapenanoic acid (EPA) are omega-3eicosapenanoic acid (EPA) are omega-3

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ProcessingProcessing

Crude fat is extracted under pressure, Crude fat is extracted under pressure, extracted by solvents, or rendered from fat extracted by solvents, or rendered from fat tissue by heatingtissue by heating

Impurities, color, and odor are removedImpurities, color, and odor are removed

Fats may be further treated to promote Fats may be further treated to promote specific qualities through hydrogenation, specific qualities through hydrogenation, winterizing, or plasticizingwinterizing, or plasticizing

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Other ProcessesOther Processes

Winterization-chilling oils to remove crystalsWinterization-chilling oils to remove crystalsHydrogenation-unsaturated fatty acids are Hydrogenation-unsaturated fatty acids are exposed to hydrogen gas in the presence of a exposed to hydrogen gas in the presence of a catalyst. Double bonds may migrate and catalyst. Double bonds may migrate and change from cis to trans configuration.change from cis to trans configuration.Interesterification or rearrangement-heating fat Interesterification or rearrangement-heating fat with a catalyst rearranges fatty acids on the with a catalyst rearranges fatty acids on the glycerol molecule making fat more glycerol molecule making fat more heterogeneous with wider range of melting heterogeneous with wider range of melting points. Used to give lard a wider plastic rangepoints. Used to give lard a wider plastic range

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Other Processes ContinuedOther Processes Continued

Acetylation-acetic acid replaces a fatty Acetylation-acetic acid replaces a fatty acid making a fat with lower melting point acid making a fat with lower melting point and the ability to stay in alpha form. Used and the ability to stay in alpha form. Used as coating agent on raisins, meat, etcas coating agent on raisins, meat, etc

Superglycerinated-emulsifier (often Superglycerinated-emulsifier (often glycerol monstearate) added to give a glycerol monstearate) added to give a wider range of melting points, more plasticwider range of melting points, more plastic

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DeteriorationDeteriorationHydrolytic rancidity-breaking of chemical bonds Hydrolytic rancidity-breaking of chemical bonds with the addition of water. Lipase may cause with the addition of water. Lipase may cause the breaking of bonds. The release of short the breaking of bonds. The release of short chain fatty acids give off flavors and odorschain fatty acids give off flavors and odorsOxidative rancidity-reaction is initiated with the Oxidative rancidity-reaction is initiated with the loss of a H from a carbon located next to a loss of a H from a carbon located next to a double bond. Carbon atom becomes a free double bond. Carbon atom becomes a free radical which is very reactive and combines with radical which is very reactive and combines with oxygen to form a peroxide free radical which oxygen to form a peroxide free radical which pulls H from another carbon and continues the pulls H from another carbon and continues the chain reaction. These peroxide free radicals chain reaction. These peroxide free radicals break into smaller volatile compounds which break into smaller volatile compounds which give the odor of rancid fatgive the odor of rancid fat

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Deterioration ContinuedDeterioration Continued

Flavor reversion-oxidative deterioriation Flavor reversion-oxidative deterioriation which involves changes in fat due to which involves changes in fat due to ultraviolet or visible light or heat in the ultraviolet or visible light or heat in the presence of oxygen catalyzed by metals. presence of oxygen catalyzed by metals. Off flavors develop that may be called Off flavors develop that may be called fishy, beany, or warmed over. Linolenic fishy, beany, or warmed over. Linolenic acid is especially susceptible to flavor acid is especially susceptible to flavor reversionreversion

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AntioxidantsAntioxidantsButylated hydroxyanisole (BHA)Butylated hydroxyanisole (BHA)

Butylated hydroxytoluene (BHT)Butylated hydroxytoluene (BHT)

Tertiary butyl hydroquinone (TBHQ)Tertiary butyl hydroquinone (TBHQ)

Propyl gallatePropyl gallate

Natural antioxidants like vitamin E or Natural antioxidants like vitamin E or tocopherols, vitamin A or beta-carotene, or tocopherols, vitamin A or beta-carotene, or vitamin Cvitamin C

Rancidity may also be controlled by cold Rancidity may also be controlled by cold temperature and the exclusion of light, moisture, temperature and the exclusion of light, moisture, and airand air

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Properties of FatProperties of Fat

Solubility-fats are insoluble in water and soluble Solubility-fats are insoluble in water and soluble in organic compoundsin organic compounds

Appearance-natural pigments, sheen, browningAppearance-natural pigments, sheen, browning

Satiety-sense of fullnessSatiety-sense of fullness

Flavor-used for flavor they impart, olive oil, Flavor-used for flavor they impart, olive oil, butter, peanut oil, bacon fatbutter, peanut oil, bacon fat

Texture-flaky pastries, smooth ice cream, crispy Texture-flaky pastries, smooth ice cream, crispy fried foodsfried foods

Shortening power-tenderness in baked productsShortening power-tenderness in baked products

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Melting point determines whether a fat is liquid, Melting point determines whether a fat is liquid, plastic, or solid at room temperature.plastic, or solid at room temperature.

1.1. Food fats are neutral fats and phospholipids. Food fats are neutral fats and phospholipids. The fatty acid attached to the glycerol molecule The fatty acid attached to the glycerol molecule gives a fat it’s characteristics. As fats cool, gives a fat it’s characteristics. As fats cool, molecules slow down, align and crystallize. molecules slow down, align and crystallize. The melting point of a fat is a measure of the The melting point of a fat is a measure of the strength of bonding forces between fatty acid strength of bonding forces between fatty acid radical and crystals. A higher attraction means radical and crystals. A higher attraction means less slowing is needed giving a higher melting less slowing is needed giving a higher melting point.point.

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Attraction between molecules or Attraction between molecules or melting point depends onmelting point depends on

1.1. Saturation versus UnsaturationSaturation versus Unsaturation• CHCH33CHCH22CHCH22COOH CHCOOH CH33CH=CHCOOHCH=CHCOOH• High LowHigh Low2.2. Length of chainLength of chain• Long Saturated Short SaturatedLong Saturated Short Saturated• Low HighLow High• Cis or trans configurationCis or trans configuration• Low HighLow High• Crystalline structure-polymorphismCrystalline structure-polymorphism• Melting point increases with crystal sizeMelting point increases with crystal size

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Polymorphism-Variation in Polymorphism-Variation in Crystalline FormCrystalline Form

1.1. Alpha-small, transparent crystals, seen Alpha-small, transparent crystals, seen in frozen desserts and candiesin frozen desserts and candies

2.2. Beta prime-delicate needles, seen in Beta prime-delicate needles, seen in shorteningshortening

3.3. Intermediate-3 to 5 microns longIntermediate-3 to 5 microns long

4.4. Beta-25 to 100 microns long, seen in Beta-25 to 100 microns long, seen in lardlard

5.5. Alpha crystals have low melting point Alpha crystals have low melting point which increases with beta crystalswhich increases with beta crystals

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Plasticity-fat has two phasesPlasticity-fat has two phases

1.1. Solid-crystals of fatSolid-crystals of fat

2.2. Liquid-oil surrounds crystalsLiquid-oil surrounds crystals

3.3. Plastic fats allow for the incorporation of Plastic fats allow for the incorporation of air in the mixing or beating process, such air in the mixing or beating process, such as creaming shortening with sugar when as creaming shortening with sugar when making cakesmaking cakes

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Heat TransferHeat Transfer

1.1. Fat conducts heat well, gives high Fat conducts heat well, gives high temperature without boiling, browns temperature without boiling, browns foods.foods.

2.2. Smoke point-temperature fat begins to Smoke point-temperature fat begins to smoke, decomposition occurssmoke, decomposition occurs

3.3. Acrolein-decomposition product which is Acrolein-decomposition product which is a derivative of glycerol is irritating to the a derivative of glycerol is irritating to the eyes and mucus membraneseyes and mucus membranes

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Choosing a Frying FatChoosing a Frying Fat

1.1. High smoke pointHigh smoke point2.2. Bland flavor, light colorBland flavor, light color3.3. Resistance to rancidityResistance to rancidity4.4. Uniformity of qualityUniformity of quality5.5. Stability for long term useStability for long term use6.6. Gives excellent taste, texture, and Gives excellent taste, texture, and

appearanceappearance7.7. Ease of use-form and packagingEase of use-form and packaging

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Care of FatCare of Fat

1.1. Use appropriate temperatureUse appropriate temperature

2.2. Adequate turnoverAdequate turnover

3.3. Filter fat dailyFilter fat daily

4.4. Remove food particles, as they can Remove food particles, as they can lower the smoke point and cause lower the smoke point and cause darkening with reduces the appearance darkening with reduces the appearance and flavor of the productand flavor of the product

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Fat AbsorptionFat Absorption

1.1. High even temperature-less absorptionHigh even temperature-less absorption2.2. Shorter time-less absorptionShorter time-less absorption3.3. Increased surface area-more absorptionIncreased surface area-more absorption4.4. Character and composition of foodCharacter and composition of food

a.a. High fat + sugar-increases absorptionHigh fat + sugar-increases absorptionb.b. Egg-increases absorptionEgg-increases absorptionc.c. Stiffer doughs-decrease absorptionStiffer doughs-decrease absorptiond.d. Softer doughs-increase absorptionSofter doughs-increase absorption

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Low-Fat CookingLow-Fat Cooking1.1. Use lean, trimmed meats and less meatUse lean, trimmed meats and less meat2.2. Use roasting or broiling cooking techniquesUse roasting or broiling cooking techniques3.3. Reduce the amount of fat used in the recipe, may Reduce the amount of fat used in the recipe, may

replace with fruit puree in bakingreplace with fruit puree in baking4.4. Use non-stick pansUse non-stick pans5.5. Use vegetable oil spray, chicken broth or water to Use vegetable oil spray, chicken broth or water to

saute foodssaute foods6.6. Use skim milk instead of whole milk or creamUse skim milk instead of whole milk or cream7.7. Use egg whitesUse egg whites8.8. Use low-fat cheeses, salad dressings, and table Use low-fat cheeses, salad dressings, and table

spreadsspreads

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Fat SubstitutesFat Substitutes Fat-Based ReplacementsFat-Based Replacements1.1. Salatrim-structured triglyceride with long and Salatrim-structured triglyceride with long and

medium chain fatty acids where breakdown is medium chain fatty acids where breakdown is decreased in the intestinedecreased in the intestine

2.2. Caprenin-structured triglyceride of capric, Caprenin-structured triglyceride of capric, caprylic, and behenic acid which are caprylic, and behenic acid which are inefficiently absorbed from the intestineinefficiently absorbed from the intestine

3.3. Olestra-hybrid fat and CHO substitute. Olestra-hybrid fat and CHO substitute. Sucrose polyester-sucrose molecule with 6 to Sucrose polyester-sucrose molecule with 6 to 8 medium chain fatty acids attached. Molecule 8 medium chain fatty acids attached. Molecule cannot be digested or absorbedcannot be digested or absorbed

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Fat Substitutes ContinuedFat Substitutes Continued Protein-Based ReplacementProtein-Based Replacement1.1. Simplesse-microparticulated egg white and milk proteinSimplesse-microparticulated egg white and milk protein Carbohydrate-Based ReplacementsCarbohydrate-Based Replacements1.1. Oatrim-maltodextrin and beta-glucanOatrim-maltodextrin and beta-glucan2.2. N-oil-hydrolyzed tapioca starchN-oil-hydrolyzed tapioca starch3.3. N-lite-starch, gums, and non-fat dried milkN-lite-starch, gums, and non-fat dried milk4.4. Stellar-cornstarchStellar-cornstarch5.5. Slendid-pectin baseSlendid-pectin base6.6. Maltrin-maltodextrin from corn starchMaltrin-maltodextrin from corn starch7.7. Rice*Trim 3 Complete-riceRice*Trim 3 Complete-rice8.8. STA-SLIM-potato starchSTA-SLIM-potato starch9.9. Avicel cellulose gel-a microcrystalling CHO derivativeAvicel cellulose gel-a microcrystalling CHO derivative10.10. Polydextrose-water soluble fiberPolydextrose-water soluble fiber

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EmulsionsEmulsions

1.1. Dispersion of one liquid in another where the Dispersion of one liquid in another where the two liquids are immiscibletwo liquids are immiscible

2.2. Three phasesThree phases• Dispersed phase-suspended dropletsDispersed phase-suspended droplets• Continuous phase-solution in which Continuous phase-solution in which

droplets are disperseddroplets are dispersed• Emulsifier-a substance with affinity for both Emulsifier-a substance with affinity for both

liquids but it is unequal liquids but it is unequal• a. Prevents coalescence of dropletsa. Prevents coalescence of droplets• b. Decreases surface tensionb. Decreases surface tension

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Types of EmulsionsTypes of Emulsions

1.1. Temporary-lowers surface tension but does Temporary-lowers surface tension but does not prevent coalescence. Example: Italian not prevent coalescence. Example: Italian dressing or home-made French dressingdressing or home-made French dressing

2.2. Semipermanent –stabilizers used to decrease Semipermanent –stabilizers used to decrease separation. Example: commercial French separation. Example: commercial French dressingdressing

3.3. Permanent-lowers surface tension and Permanent-lowers surface tension and prevents coalescence. Example: mayonnaiseprevents coalescence. Example: mayonnaise

4.4. Emulsifying agent-phospholipids, lecithin, Emulsifying agent-phospholipids, lecithin, phosphatidyl ethanolamine from gelatin, egg phosphatidyl ethanolamine from gelatin, egg whites, egg yolks, casein, whey, cellulose whites, egg yolks, casein, whey, cellulose derivatives, spices, vegetable gums, and derivatives, spices, vegetable gums, and starch pastesstarch pastes

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Power Point AuthorPower Point Author

Dr. Jane RossDr. Jane Ross

The University of Vermont

Foods and Nutrition

Basic Concepts of Food