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Fat Substitution in Food. Miranda Miller Kraft Foods R&D ACCA Seminar Series October 4, 2005. Agenda. Why Fat Replacement? Basic Fats and Oils Technology Functions of Fat in Food Fat Mimetic Technology Reduced Calorie Fats and Fat Substitutes Replacing Trans and Saturated Fat.
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Fat Substitution in Food Miranda MillerKraft Foods R&D ACCA Seminar SeriesOctober 4, 2005
Agenda • Why Fat Replacement? • Basic Fats and Oils Technology • Functions of Fat in Food • Fat Mimetic Technology • Reduced Calorie Fats and Fat Substitutes • Replacing Trans and Saturated Fat
Overweight and Obesity in America • Over last 25 years, been a dramatic increase in percent of population in North America who are overweight and obese. • Jane Doe is 5’5” and weighed 130 lbs (BMI= 22) in 1980, in 2004 she weighs 160 lbs (BMI=27). How much would Jane have to change her eating behaviors to gain this weight? Decrease in activity level= 10 minutes more commuting/day over 25 years • Increase in caloric consumption= 12 calories/day over 25 years • 2 Life Savors • ¼ cup of skim milk
July is National Hot Dog Month!!! • 80 % of the people at a baseball game eat a Hot Dog. • 5 Billion Hot Dogs eaten between Memorial Day and Labor Day. • 50 million Hot Dogs eaten every day in the US: that’s 80 Hot Dogs/person/year!! • 1 Hot Dog has about 150 Calories.
Comparison of Hot Dogs • Beef/Pork Hot Dog:150 Cal; 5 grams Protein; 1 gram CHO; 13 g Fat; 81% Cal from fat • 4.8 g Sat Fat; 6.2 g MUFA; 1.2 g PUFA • Turkey Hot Dog:102 Cal; 6 g Protein; 1 g CHO; 8 g Fat(71%) • 2.4 g Sat Fat; 2.7 g MUFA; 2.1 g PUFA • Chicken Hot Dog:115 Cal; 6 g PRO; 3 g CHO; 9 g Fat(70%) • 2.5g Sat Fat; 3.8 g MUFA; 2.8 g PUFA
Weight Gain • 3500 extra Calories = 1 pound of Fat • Example: 80 hot dogs per person/year • above required Calories • 80 dogs x 150 Calories = 12000 Cal/year • 12000/3500 = 3.5 # / year
Why Fat Replacement? • High fat diets are linked to obesity and cardiovascular disease • There is an epidemic of overweight and obesity in the US • About 65% are overweight (BMI 25) • (BMI = weight (kg) / Height 2 (m2) • About 23% are obese (BMI 30) • RDA for fat is 30% of calories • Current consumption is somewhere near 38%
Consumers Are Paying Attention to What They Eat “A person should be very cautious serving food with…”
Some Other Consumer Facts • Concern about fat peaked in mid 90’s • 51% very cautious in 1994 • 31% very cautious in 2004 • Low carb diets may be the diet du jour but • 73% consume reduced fat food • 78% are trying to cut down fat in their diet • 61% trying to avoid trans fat • And 70% are concerned with calories
Lipids: Definition • A family of compounds soluble in organic compounds but not in water • 3 classes of food lipids: • Triglycerides: 95 % of lipids in foods • Phospholipids: e.g..: lecithin • Sterols: e.g..: cholesterol
Triglycerides Are Esters of Glycerol and Fatty Acids condensation reaction Glycerol + 3 Fatty Acids Triglyceride + 3 water molecules Structures linked by ester bonds (R-COOR') and water is released
Some Basic Facts About Fats • Major source plants (soybean, cottonseed, corn, palm) • At room temperature, Oil = liquid, Fat = solid (m.p. varies) • Calorie-dense (9 Kcal/gram) vs. carbs & protein (4 Kcal/g) • Per capita consumption ~80 lb/year (significant inc. since 1980) • 38% of dietary calories come from fat (current RDA is 30%) • Saturated and trans-fat consumption increase CHD risk • Unsaturated oils (olive, fish oils) appear to reduce CHD risk
Fatty Acids Vary in Chain Length and Saturation Add Double Bonds Lower Melting Point saturated stearic acid m.p. 73 oC “cis” monounsaturated oleic acid m.p. 5.5 oC Longer Chain Higher Melting Point
“cis, cis, cis” linolenic acid m.p. –24 oC “cis, cis” linoleic acid m.p. –13 oC Poly-Unsaturation Confers Liquidity (And Reactivity Toward Oxygen) More Double Bonds Lower Oxidative and Thermal Stability
“sat” stearic acid m.p. 73 oC “cis” oleic acid m.p. 5.5 oC “trans” elaidic acid m.p. 42 oC Hydrogenation Improves Stability BUT… H2 Trans fats behave more like saturated fat
Nutritional Role • Source of essential fatty acids • Linoleic and linolenic • Carriers for fat soluble vitamins • A, D, E and K • Important source of energy • 9 Kcal/g vs. 4 Kcal/g for carbs or protein
Physical and Chemical Functions Physical Properties of Foods Rheological properties: viscosity, plasticity, yield stress, thixotropy, gelation, spreadability, lubricity, hardness, stringiness Thermal properties: melting characteristics, heat transfer coefficient, solid fat index, softening point, polymorphism Processing behavior: heat stability, viscosity, crystallization, aeration Post-processing and shelf stability: shear sensitivity, tackiness, migration, dispersion, and stability (physical, chemical, microbiological) Chemical Properties of Fat or Oil Length of carbon chain Degree of unsaturation Distribution of fatty acids Cis-trans configuration Crystal state of fat
Sensory Functions of Fat in Products • Appearance • Gloss, translucency, color, surface uniformity, crystallinity • Texture • Viscosity, elasticity, hardness • Flavor • Intensity of flavors, flavor and aroma release, flavor profile, flavor development, time intensity relationships • Mouthfeel • Meltability, creaminess, lubricity, thickness, degree of mouthcoating, mouth warming or cooling
Many Fats and Oils in Food Exist As Emulsions Discontinuous phase Internal phase Dispersed phase Continuous phase External phase Dispersion Medium
Emulsion Types W/O EMULSION O/W EMULSION OIL WATER OIL WATER Examples: Margarine Tablespread Butter Examples: Mayonnaise Milk Salad Dressing Coffee Whiteners
Historical Context • Consumers became aware of impact of diet on health in 80’s • Proposed energy from fat in diet reduced to 30% (from 40-49%) • Began affecting consumer attitudes • Challenge was to produce low-fat products with physical and sensory characteristics as close as possible to full-fat quality • “Breakthrough” came with introduction of a microparticulated protein ingredient called “Simplesse” • The search for the next magic bullet ingredient followed • Subsequent development effort revealed consequences of removing fat from a product • Alternative ingredients or processes had to be developed as all the attributes of fat became recognized
Classification • Over 200 commercial fat replacement ingredients • Carbohydrate-based • Starch and starch hydrolysis products • Fiber based (gums, gels, thickeners, bulking agents) • Protein-based • Specially processed proteins • Protein/fiber combinations • Lipid-based • Synthetic fat substitutes • Low-calorie fats • Emulsifiers
Approach to Fat Replacement Has Changed Late 80’s to Mid 90’s Fat free products with full fat qualityusing magic bullettechnologies • 21st Century • Healthy products with balanced macronutrients • Fat is a necessary part of diet • Need to cut down bad fats: saturated and trans • Good tasting calorie-reduced light products
Some Basic Terminology • Fat Replacer • Blanket term for any ingredient used to replace fat • Fat Substitute • Synthetic compound used as direct 1-for-1 replacement • Similar chemical structure to fat but resist digestion • Fat Mimetic • Non-fat substance requiring high water content • Replace some (not all) functions of fat in products • Low-calorie fat • Synthetic triglyceride combining unconventional fatty acids resulting in reduced calorie content • Fat Extender • System of ingredients used in combination with standard fats or oils to achieve fat reduction
Fat Replacement Strategies • Direct Fat Removal • First strategy to evolve in rush to comply with nutritional recommendations in 80’s • Worked well for milk, some dairy products, some processed meat… but not much else • Formulation Optimization • Water replaces fat in higher fat products • Optimization with functional ingredients to stabilize product • Processing Technology • Vary processing conditions (time, temp, pressure, etc.) to cause interactions in ingredients or change functionalities • Holistic Approach • No single replacer can do it all
Fat Reduction Success Story • Miracle Whip brand salad dressing was one of Kraft's earliest successes at fat reduction, being introduced in the 1930's • Miracle Whip was formulated to provide about half the fat of conventional mayonnaise using a starch gel at about one tenth the level of the fat that it was replacing • Miracle Whip’s success over its 70+ year lifetimeis in part due to the fact that it did not try to duplicate the product that it was replacing, but rather developed its own unique flavor and mouthfeel which is a function of the newmacronutrient composition of the product
Full Fat Emulsion Products Have Multiple Phases (80%) (20%) (80%) (20%)
Something Needs to Replace Fat in Lower Fat Foods Passive Active
Fat Mimetic Mechanisms for Emulsion Products • There are at least 5 mechanisms by which fat mimetic ingredients act to provide fat texture: • Entanglement • Network Gels • Particle Gels • Aggregates • Non-interacting Particles • Each provides different rheological properties to a product that the mimic dispersed or continuous phase of an emulsion product such as mayonnaise
Entanglement and Gelation Mimic Continuous Phase • Entanglement • Long non-gelling, non-interacting polymers that have large spheres of hydration • Provide slipperiness and viscosity • Mimic the continuous phase of mayonnaise • Examples are xanthan gum, carrageenan, polydextrose • Network Gels • Polymers interact with each other to form more or less permanent junction zones • Provide yield stress and gel structure • Mimic the “cut” of a mayonnaise • Examples are pectin, alginates, gelatin
Particle Gels Mimic Dispersed Phase • Network forms between polymers but is not continuous throughout the system • Simplesse, “breakthrough” fat mimetic, is particle gel made by microparticulation of whey protein • Mimic the dispersed phase of mayonnaise • Performance affected by size, shape, surface properties, and rigidity (or deformability) of the particle • Examples: colloidal cellulose and small particle starch • Can also be formed by shearing network gels • Provide creaminess and body
Interactions Between Particles (or Not) • Particle Gel Aggregates • Discrete crystalline or gel particles that reassociate with each other to form aggregate • Similar in functionality and constraints to particle gels • If aggregate is continuous, can mimic both dispersed and continuous phases • Examples include starch gel, starch hydrolysates or microcrystalline cellulose (cellulose gel/cellulose gum) • Non-Interacting Particles • Inert particles • Provide opacity and reduce cohesiveness • Examples include uncooked or retrograded starch, crystalline cellulose
Microbiological Considerations • Regardless of the mechanism, water is the main ingredient that replaces fat • Fat mimetics hold water so that it builds texture like fat • Shelf life and microbiological safety are affected by combination of water activity, acidity, salt, preservatives, heat treatment • Addition of water requires increasing other safety measures • Typically acidity of aqueous phase is increased • Control of pH is critical • Strong acidic notes affect overall sensory quality
Fat Mimetic Systems - KFM Ingredients: Water, modified food starch, sugar, high fructose corn starch, vinegar, soybean oil*, salt, cellulose gel, natural flavor, artificial flavor, egg yolks*, xanthan gum, mustard flour, lactic acid, cellulose gum, phosphoric acid, vitamin E acetate, lemon juice concentrate, dried garlic, dried onions spice, yellow 6, beta carotene, blue 1, with potassium sorbate and calcium disodium EDTA as preservatives *Trivial source of fat and cholesterol
Approach to Fat Mimetics Has Evolved • Because of “missing attributes”, most food manufacturers have taken a step back from fat free • The learnings from fat free days have allowed creation of more and better light, low-fat and reduced-fat products
O H2- C | C | C -O-C-(CH2)n-CH3 Change the linkage O - H CH3-(CH2)n-C-O- O H2- -O-C-(CH2)n-CH3 Change the backbone Change the fatty acid What Is the Logic Behind Fat Substitutes? Think like a lipase… ...what would make a triglyceride less appealing?
Olestra Is Only FDA-approved Noncaloric Fat Substitute • Chemistry: Different Backbone • Sucrose: a disaccharide from glucose and fructose • 8 hydroxyl groups for esterification • Fatty acid esters at 6 to 8 sites Typical triglyceride Sucrose Octaoleate
Olestra Approved for Savory Snacks • Current approval only in prepackaged ready-to-eat savory (i.e. salty or piquant but not sweet) snacks and prepackaged, un-popped popcorn kernels that are ready-to-heat • Approved as food additive for savory snacks (chips, crackers, etc) in 1996 • Ruling expanded in 2004 to include popcorn • In 2003, FDA removed requirement for advisory label warning on products made with olestra
Absorption Decreases With More Esters Mattson and Volpenhein, J. Nutr. 1972