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

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).

Increase in caloric consumption= 12 calories/day over 25 years

2 Life Savors ¼ cup of skim milk

Decrease in activity level= 10 minutes more commuting/day over 25 years

How much would Jane have to change her eating behaviors to gain this weight?

Overweight and Obesity in America

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%

Show Obesity Maps

Consumers Are Paying Attention to What They Eat

30% 30% 30%26%

31%23% 20% 19%

13%

29% 26% 26%27% 21%

21%21% 21%

18%

Fat

Satura

ted F

ats

Salt

Cholest

erol

Trans

Fats

Perse

rvat

ives

Sugar

Caffe

ine

Carboh

ydra

tes

Agree Mostly

Completely Agree

“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

Basic Fats and Oils Technology

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

Structures linked by ester bonds (R-COOR') and water is released

Glycerol "backbone" is a water-soluble

alcohol

Fatty Acids are chains of carbon atoms with a methyl (-CH3) group at one end and a

carboxylic acid (-COOH) group at the other

Glycerol + 3 Fatty Acids

Triglyceride + 3 water molecules

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

saturatedstearic acidm.p. 73 oC

“cis”monounsaturated

oleic acidm.p. 5.5 oC

Longer Chain Higher Melting Point

Add Double Bonds Lower Melting Point

Poly-Unsaturation Confers Liquidity (And Reactivity Toward Oxygen)

“cis, cis”linoleic acidm.p. –13 oC

“cis, cis, cis”linolenic acidm.p. –24 oC

More Double Bonds Lower Oxidative and Thermal Stability

Hydrogenation Improves Stability BUT…

“sat”stearic acidm.p. 73 oC

“trans”elaidic acidm.p. 42 oC

“cis”oleic acid

m.p. 5.5 oC

Trans fats behave more like saturated fat

H2

Functions of Fat in Food

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

Chemical Properties of

Fat or OilLength of carbon chain

Degree of unsaturation

Distribution of fatty acids

Cis-trans configuration

Crystal state of fat

Physical Properties of FoodsRheological 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)

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 phaseInternal phaseDispersed phase

Continuous phaseExternal phaseDispersion Medium

Emulsion Types

O/W EMULSION W/O EMULSION

OIL

OIL WATER

WATER

Examples: MayonnaiseMilkSalad DressingCoffee Whiteners

Examples: MargarineTablespreadButter

Microstructure of Mayonnaise

Fat Replacers

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 bullet

technologies

21st CenturyHealthy 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 Mimetic Technology

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

Thermal

- Subtle Warmth

Flavor - Release

- Intrinsic Flavors - Time Intensity Profile

Appearance - Whiteness and Opacity

Organoleptic - Lubricity and Mouthcoating

- Yield Stress at Low Shear Rates - Creaminess, Viscosity, Thickness

- Unique Bulk Textures of Cohesiveness, Cut and Peaks

Spoonable Dressings Example

Full Fat Emulsion Products Have Multiple Phases

Dispersed Phase

Continous Phase

Spread

Aqueous Solution of Dairy Proteins, Salt, Gums, etc.

Crystalline and Liquid Oil

Dressing Emulsified Liquid Oil Droplets

Aqueous Solution of Proteins and Carbohydrates

(20%)(80%)

(80%)

(20%)

Something Needs to Replace Fat in Lower Fat Foods

Product Fat Level Formulation Strategy

Milk Yogurt

Pudding Cottage Cheese

5% < 1%

- Adjust Protein, Water, Carbohydrate Ratio - Add Low Levels of

Texture Modifying Ingredients

Spreads Dressings

70-80% < 2%

- Fat Replacement: Substitute or Mimetic

Physical replacement Modify nonfat comp. Control Moisture

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

The Missing Attributes Needs to address gaps

Flavor partitioning, delivery, character

Reservoir (solvent) for flavor compounds

Mouthfeel factors such as oiliness and mouthcoating

Separate phase from aqueous portion, surface active

Thermal properties of mouthwarming and melt transitions

Liquid at body temperature, Melting transition below body temperature

Current Fat Mimetics Cannot Supply Full Fat Quality

Approach to Fat Mimetics Has Evolved

Because of “missing attributes”, most food manufacturers have taken a step back from fat freeThe learnings from fat free days have allowed

creation of more and better light, low-fat and reduced-fat products

Reduced Calorie Fat Substitutes

What Is the Logic Behind Fat Substitutes?

Think like a lipase… ...what would make a triglyceride less appealing?

C|C|C

H2-

H2-

- H

-O-C-(CH2)n-CH3

-O-C-(CH2)n-CH3

CH3-(CH2)n-C-O-O

O

O

Change the backbone

Change the fatty acid

Change the linkage

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

Backbone Number of Esters

Absorbability

Glycerol 3 100%

Erythritol 4 70%

Xylitol 5 50%

Sucrose 8 0%

Mattson and Volpenhein, J. Nutr. 1972

Does Olestra Function the Same As Triglyceride?

Melting properties vary with fatty acid comp Composition limited to C16-C22, specified degree of

unsaturation Physiological stability (measured by stiffness) requires

incomplete melting

Crystallinity, and polymorphic behavior of crystals, are not the same as TG

Properties of certain fats (e.g. Cocoa butter) rely on specific crystal structures

•Emulsion properties (e.g. Size of droplet) partially dependent on viscosity

Triglycerides Can Be Low Calorie Too!

Commercial options: Salatrim or Caprenin TG containing mixed long chain saturated

fatty acid (LCFA, C18-22) with short or medium chain fatty acids (SCFA, C2-4 or MCFA, C6-10)

Preferred Comp: 1 LCFA: 2 S/MCFA Approximate Caloric Content: 5 cal/g Low Cal due to poor absorption of LCFA

Salatrim/Caprenin Functionality

Melting properties controlled primarily by length of short or medium chain fatty acid

0

10

20

30

40

50

60

70

80

Chain Length

2

3

4

6

8

10

12

14

Melt

i ng P

oin

t (°

C)

Replacing Trans and Saturated Fat

Trans Fatty Acids in Shortening

Most difficult challenge has been to replace trans fat in shortening Solid fats are desirable in baked products Saturated fats were replaced by hydrogenated (trans) fats

when health issues surrounding sat fat became known

Science supports the link between trans fatty acids heart disease risk Trans fats elevate LDL cholesterol levels, lower HDL

Major source of dietary trans-fat is partially hydrogenated vegetable oils

Trans Fat Replacement in Reduced Fat Snacks

In the case of baked snacks (crackers and cookies) reformulation to reduce trans fat has been a multi-year research and development effort Liquid vegetable oils would be ideal ingredients because of

their inherently low levels of trans-fat and saturated fat A non-hydrogenated, RBD (refined, bleached and

deodorized) soybean oil was found to perform “adequately” in Nabisco’s SnackWells crackersand cookies owing to their low fat andreduced fat formulas (generally 2-3grams of total fat per serving)

Trans Fat Replacement in Full Fat Snacks

In comparable “full fat” products that contained > 4 fat grams per serving, the food matrix was insufficient to hold the liquid oil in place, Liquid soybean oil “drained” out of such a

product by the action of gravity, and failed to deliver the buttery, signature flavor and light open texture expected by Ritz cracker consumers.

Trans Fat Replacement Solution First practical, low trans-fat solution involved the

use of high melting point mono- and di-glyceride emulsifiers as minor components in liquid oils Used with Triscuit crackers, a product with a high

surface area provided by a woven wheat structure The oil blend containing 4-8% emulsifier

was topically applied to this productimmediately upon its exit from the oven

Worked with Triscuit and Wheat Thins, but not Ritz Needed to change the fat in the dough, as well

as that brushed on top of the cracker

Fat Reduction/Replacement: Summary

Fat mimetics replace the fat in a product, though often sacrificing texture and/or flavor. For this reason, partial fat replacement is generally a more consumer acceptable approach

Trans fatty acids can be replaced , though it is very difficult to remove these fats from baked foods. However, withinvestment of significantresearch efforts, successis possible and in factcan drive sales growth