M lti M di B kiMulti-Media Baking TechnologyTechnology

Mihaelos N. MihalosMondelēz International LLCMondelēz International LLCNorth America Region Biscuit Research, Development & Quality GroupEast Hanover, NJMay 7, 2013

Abstract:

Baking is a critical unit operation in biscuit manufacturing: the high energy reactionphase maximizing chemical and physical transformations of raw dough into finishedp g p y f f g fproducts. Traditional baking depends on Direct Gas Fired (DGF) or convection systems.Recently, radiant and microwave energy have been added to hybrid combinations ofDGF and convection. These “multi-media” ovens permit effective control of thep ff freactions that determine finished product attributes through decoupling of conduction,convection, radiant and dielectric heat transfer modes. Microwave, DGF and radiantheat mainly impacts structure, thickness and texture. Microwave and convection havey pthe greatest effect on moisture and weight. Finally, color can be readily adjusted byradiant and DGF modes of baking. Humidity also plays a key role. This approach tobaking processes through multi-media ovens develops understanding of thefundamental characteristics and interactions for baking reactions in terms of materials,process and product. It permits optimized process and oven designs through specificheat transfer data for scale up from pilot plant to production ovens.

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Mondelēz International Global Brands

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Product Attributes Developed:

• FormulaFormula

• Mixing• Mixing

• Machining• Machining

B ki• Baking

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Different Zones Do Different Jobs

Stage 3Stage 1

Stage 2

Stage 3Stage 1

• Ovens are divided into different zones, but the principles of the baking stages remain the same

Stage 1: Structure Development– Stage 1: Structure Development– Stage 2: Moisture Removal – Stage 3: Color & Flavor Developmentg p

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Stage 1: Cracker Structure Development

• Development of the cracker structure starts as starch begins to cook• Drying begins

Front End Heat is Critical

• Drying begins• Ammonia, carbon dioxide gases & water vapor are formed and released.

These cause the cracker to ‘lift’ Dimension development Stack height Gases expand & give more ‘lift’ Structure development A i i d b b bbl Ammonia aroma carried away by gas bubbles

StructureStage 1

• Bottom heat allows the cracker to heat up, without drying out the top surface too quickly If the top surface dries out too quickly it may cause:

Development

surface too quickly. If the top surface dries out too quickly, it may cause:– Moisture to get trapped inside the cracker center– The cracker to have low stack height and high moisture

P ibl ‘ h ki ’ bl– Possible ‘checking’ problems

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Stage 2: Cracker Moisture Removal• Continues to remove ‘free water’ from the dough piece• Maximum gas/dough piece expansion achieved• Product volume relaxes• Fixing the product structure:

– Starch cooks– Gluten proteins change (denaturize)

• Crusting of the product surface begins• Crusting of the product surface begins Drying Shell/Surface Formation

Stage 2

• If crusting of the surface begins too early in the second stage ‘blisters’ may resultstage, blisters may result

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Stage 3: Cracker Color Development

• Majority of moisture removed during Stages 1 & 2 and coloring now occurs

• Structure is fully set and product is firm• The color develops due to:

– Sugar caramelization– Sugar / protein reactions (Maillard browning)

These also develop flavor• These also develop flavor

Development of Color & Flavor

Stage 3

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Stage 1: Cookie Structure Development• The sugar & fats melt, causing ‘spread’ (flow) when the raw product

comes in contact with the band• The more sugar in the dough the less the starch can be cooked• The more sugar in the dough, the less the starch can be cooked.

The dough becomes fluid & no, or little structure develops • Drying begins• The release of water vapor in the early zones covers the product in

a steam blanket. Evaporative cooling keeps the surface temperature down. This:

– Conditions the dough– Keeps the product surfaces flexible so that moisture & leavening gases

can be releasedcan be released

Gases Water and AirHot Oven Dough Surfaces Soft

Gases Water and Air Spreads the Product Steam Coating Dough

H t O B dHot Oven Band

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Stage 2: Cookie Moisture Removal

• Continue to release ‘free water’ from the dough• Leavening gases & water are still ‘lifting’ & ’spreading’ the dough,

til i l i h d d th iddl f St 2until maximum volume is reached around the middle of Stage 2– Good ‘lift’ & ’spread’ improve the texture of the finished product– Little, or no structure is being developed because of the high level , g p g

of sugar and the low level of water. This reduces starch cooking

• Color development starts on the top surface as highertemperatures are reachedtemperatures are reached

Maximum Liftand ‘Spread’ Reached

Surfaces Starts to Seal and Some Color Develops No or Little

Structure Development p

Hot Oven BandHot Oven Band

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Stage 3: Cookie Color Development• Maximum ‘lift’ & ‘spread’ in the product is reached• Due to the lack of cooked starch the cookie surface collapses• The air pockets developed from the ‘lift’ give the cookie

texture & lightnessIf ‘lift’ i th ki ill h h h l t t t– If ‘lift’ is poor, the cookie will have a harsh, unpleasant texture

• Top & bottom color & flavor are developed as the:– Syrup / sugars react with the flour proteins at around 320°F (160°C)Syrup / sugars react with the flour proteins at around 320 F (160 C)– Syrup / sugars begin to caramelize at around 340°F (171°C)

Maximum Volume of Spread Reached

Cookie Collapse

Air Pockets Develop LightOpen Texture

Maximum Volume of Spread Reached

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How heat passes from the oven to the product C i l H i M h d P H

1 C d ti

Conventional Heating Methods Pass Heat From the Oven to the Product by 3 Mechanisms:

1. Conduction2. Radiant 3 ConvectionConvection R di t3. Convection Convection

(Air flow)Radiant

Conduction Convection

RadiantRadiant

• The top of the product is mainly heated by convection & radiantf• The bottom of the product is mainly heated by conduction thru

the heated oven band• The bottom of the oven band is mainly heated by convection & radianty y

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Conduction in a DGF OvenConduction in the oven occurs as the heat transfers directly from the hot oven band into the bottom of the dough pieces

Oven Band

This effects product structure and dimension

Conduction particularly melts the fat to enhance flow of the dough. g

Conduction heats the dough piece from below, g pchanging water into steam. This helps lift the stack height

and pushes steam up through the surface for moisture removal

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di h i f h h l f

Radiant Heat in an ovenRadiant heat in an oven comes from the hotter metal surfaces,

burners’ flames & combustion gases. The heat then transfers to the product: p

Radiant heat particularlybrowns the top surface

of the product!

Metal oven surfaces

Burners’ flames

Radiant heat has a particular impact on uneven surfaces. The shadowed areas will receive less radiant heat than

exposed parts. This makes brown highlights at exposed points p p g g p p

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Radiant Burners• Operated at extremely high temperatures, in order to radiate

heat to the productC b i t ll d t l ti i th• Can be installed at any location in the oven

Burner surface temperature + 1000°F / 538°+CBurner surface temperature + 1000 F / 538 +C

If installed in the First zone If installed in the End zones. Used for immediate dough coloring. Used for final coloring

• Operate like a ‘giant toaster’!Exhaust

Gas Air

SparkSpark

Product

Radiant burners are currently being researched

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Natural Convection in an ovenAir in the oven chamber is continually circulating as

incoming cooler air warms, lightens and rises.It is difficult to manage and controlff g

Natural convection air flow inside the oven! Hot oven inner surfaces!

DischargeCooler

InputCooler

i air air

Convection heat is important in lifting moistureMoving oven band

Convection heat is important in lifting moisture in the form of steam away from the surface of the product. This further supports achieving finished product moisture

specification. Speed of moisture removal effects product qualityspecification. Speed of moisture removal effects product quality

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f f

Forced Convection OvensForced convection comes from oven fans

that heat air and blow it into the oven chamber

Air humidity level close to product is 90% RH from oven entrance to middle

Forced convection helps to even out heat differences in an oven

When different temperatures are needed in different zones the heat can be controlled by the zones baffles

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Microwave Processing

• Microwaves are a form of electromagnetic energy just like radio waves, television signals and light waves

• In cooking and baking applications, microwaves operate by vibrating water molecules at 2450 MHz

• This vibration generates heat which helps speed up the baking process by “baking from the inside out”

Ch i h i i di• Changes with microwave energy are immediate as compared to conventional baking

• Microwaves help control the moisture and stack height• Microwaves help control the moisture and stack height of the product

• In crackers the bake time can be reduced from 10-15%In crackers, the bake time can be reduced from 10 15% to provide a 10-15% through put increase

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Microwave Processing

• Enhances Coupling to the ProductI R ti R t• Increase Reaction Rates

• Shorten Bake Times• Manages Product Properties

– MoistureStack Height– Stack Height

– Color

• Decouples the attributes of moisture and stack heightDecouples the attributes of moisture and stack height as well as increasing throughput

• US Patent 5,945,022 discusses processing, , p g

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Overview of the Microwave System

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Microwave Assisted Baking

Increased production by reducing baking times:

Combines the features of conventional DGF & microwave baking:

• Increased production by reducing baking times: Because structure development & moisture removal are both enhanced by microwave baking

• Improved process by enabling independent control of:– Stack height

Moisture content– Moisture content

• Improved product quality by heating the center of the product equally

Conventional Heat

Microwave Heat

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Radio Frequency (RF) Dryer For Post-Bake ConditioningConditioning• Located either after, or in the oven itself• The product is baked to a higher moisture level in the oven• Makes the water in the product vibrate & heat up which

releases the moisturereleases the moisture• Higher moisture levels will attract more dielectric energy.

Therefore it is a “self regulating’’ moisture controlg gHigh Moisture = More Energy Low Moisture = Less Energy

CConveyor

Electrodes (+ -)High Frequency Dielectric System Radio frequency

power source

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The Traditional Baking Process

C ti• Convection

• Conduction

• Radiant

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Multi-Media Baking Constants

• Changing the heat generation systems by altering the different forms of convection, DGF, Radiant andthe different forms of convection, DGF, Radiant and surrounding them with dielectric results in changing the heat transfer rate

• This results in altering the baking constants allowing the product attributes or characteristics to be manipulated

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Hybrid Ovens:DGF & Forced Convection Baking CombinedDGF & Forced Convection Baking Combined• DGF (Direct Gas Fired) heat achieves the product structure

development at the beginning of the baking processTh ti d f i t l & l• The convection zones are used for moisture removal & colordevelopment

• Convection heat enhances the uniform side to side baking resulting i i d b l i f th d t tt ib tin improved balancing of the product attributes

• Due to the even heat in a forced convection zone, temperatures are easier to measure

Forced ConvectionForced ConvectionDGF

• There are hybrid ovens in many bakeries used to produce CRACKER productsCRACKER products

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Humidity Control Theory

• The concept behind using humidity for controlling baking is that higher humidity air has an increased heatbaking is that higher humidity air has an increased heat capacity resulting in more efficient heat transfer to the product thereby reducing the bake time.

• The higher humidity in the zone delays the moisture migration from the dough piece. Baking becomes “ ” l ti f th ( t ti l“even” over a longer portion of the oven (potential reduction on checking/breakage; reduce case hardening and burned edges)g )

• Future systems will require designing features into the oven to measure humidity in the bake chamber.

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Multi-Media Ovens Consist of:

• Convection• Conduction• Radiant • Dielectric

Benefits

• These alternative baking sources deliver unique products or attributes by altering heat transfer or baking constantsattributes by altering heat transfer or baking constants

• Provides productivity opportunities via the baking process by enhancing the oven with alternative dielectric energy sourcesg gy

• Uniform baking and moisture removal is improved

• Improved control of product thickness and reducing finished gproduct losses

• Provides the capability of scaling up processes from pilot plant to productionto production

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Mih l (Mi h l) Mih l i S i A i P i i l E i f N h A i R i Bi i R&D G i P

Michael Mihalos: 973-503-2168Mihaelos (Michael) Mihalos is a Senior Associate Principal Engineer of North American Region Biscuit R&D Group in ProcessDevelopment for Mondelēz International. He is responsible for managing leading edge, very complex technology development projects.

Mihalos joined Nabisco in 1988 as a Process Engineer in Biscuit Engineering and holds various U.S. patents for his development work.He has held a variety of technical positions in his 25 years at Nabisco/Kraft/Mondelēz International in areas such as Biscuit ProcessEngineering, Process R&D, Technical Services, Manufacturing Development, Pilot Plant, Growth Engineering, Global Biscuit ProductDevelopment (PD) and currently in North America Innovation. He is a recipient of the Kraft Foods 2011 Technical Leadership Award forResearch, Development and Quality .

He spent time in biscuit manufacturing facilities understanding bakery biscuit operations and processing and currently continues toprovide pilot plant and technical support in the area of process development for Innovation Platforms for cookies, crackers& snacks, Responsibilities include management of all schedule, budget, scoping components and leading overall efforts in processdevelopment of new products. He identifies and develops new processes and process technologies in support of the product developmentb i l d i l t “Fi ld R d ” t h l i d i d t/ l tf H h d l d lti l biliti ibusiness plan and implements “Field Ready” technologies used in product/platforms. He has developed multiple process capabilities ininnovative technologies implemented this expertise to improve productivity, product quality, and commercialization of new productsresulting in 60 + U.S. and International Patent and pending patent applications. He provides process leadership by hosting a ProcessDevelopment Community Of Practice conference within Mondelēz International organization to share new technologies as well asbrainstorming opportunities from the various business categories such as beverages, coffee, cheese, gum and candy, etc.

Prior to joining Nabisco, Mihalos worked in both research & development and engineering as a chemical engineer for Colgate Palmolive inJersey City, NJ.

Mihalos is a member of the American Institute of Chemical Engineers, Institute of Food Technologists and both a member as well asMihalos is a member of the American Institute of Chemical Engineers, Institute of Food Technologists and both a member as well ascertified by the American Chemical Society. He is also an alumnus of both Columbia University and Fordham University. Mihalos receiveda B.S. in Chemistry from Fordham University, a B.S. in Chemical Engineering from Columbia University and an M.S. in ChemicalEngineering from Columbia University. He is an alternate for the Biscuit & Cracker Manufacturer Education Committee and presents atthe annual technical conference. He also edited the processing section in the 4th edition of “Baking Science and Technology” Volume II.Mih l li i P li d P k NJ H lik t l b k tb ll d d i it t l b t i t ltMihaelos lives in Palisades Park, NJ. He likes to play basketball, read, and visit museums to learn about ancient cultures.

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