Mihaelos N. Mihalos. North America Region Biscuit Research, Development & Quality Group East Hanover, NJ May 7, 2013

Transcription

1 Multi-Media M Baking Technology Mihaelos N. Mihalos Mondelēz International LLC North America Region Biscuit Research, Development & Quality Group East Hanover, NJ May 7, 2013

2 Abstract: Baking is a critical unit operation in biscuit manufacturing: the high energy reaction phase maximizing chemical and physical transformations of raw dough intofinished products. Traditional baking depends on Direct Gas Fired (DGF) or convection systems. Recently, radiant and microwave energy have been added to hybrid combinations of DGF and convection. These multi-media ovens permit effective control of the reactions that determine finished product attributes through decoupling of conduction, convection, radiant and dielectric heat transfer modes. Microwave, DGF and radiant heat mainly impacts structure, thickness and texture. Microwave and convection have the greatest effect on moisture and weight. Finally, color can be readily adjusted by radiant and DGF modes of baking. Humidity also plays a key role. This approach to baking processes through multi-media ovens develops understanding of the fundamental characteristics and interactions for baking reactions in terms of materials, process and product. It permits optimized process and oven designs through specific heat transfer data for scale up from pilot plant to production ovens. 2

3 Mondelēz International Global Brands 3

4 Product Attributes Developed: Formula Mixing Machining Baking 4

5 Different Zones Do Different Jobs Stage 1 Stage 3 Stage 2 Ovens are divided into different zones, but the principles of the baking stages remain the same Stage 1: Structure Development Stage 2: Moisture Removal Stage 3: Color & Flavor Development 5

6 Stage 1: Cracker Structure Development Development of the cracker structure starts as starch begins to cook Drying begins Front End Heat is Critical 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 Ammonia aroma carried away by gas bubblesbbl Stage 1 Structure Development 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: Moisture to get trapped inside the cracker center The cracker to have low stack height and high moisture Possible checking problems 6

7 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 Drying Shell/Surface Formation Stage 2 If crusting of the surface begins too early in the second stage, blisters may result 7

8 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 Development of Color & Flavor Stage 3 8

9 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 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 released Steam Coating Dough Hot Oven Dough Surfaces Soft Gases Water and Air Spreads the Product Hot Oven Band 9

10 Stage 2: Cookie Moisture Removal Continue to release free water from the dough Leavening gases & water are still lifting & spreading the dough, until 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 of sugar and the low level of water. This reduces starch cooking Color development starts on the top surface as higher temperatures are reached Maximum Lift and Spread Reached No or Little Structure Development Surfaces Starts to Seal and Some Color Develops Hot Oven Band 10

11 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 & lightness If lift is poor, the cookie will have a harsh, h unpleasant texturet Top & bottom color & flavor are developed as the: 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 Light Open Texture 11

12 How heat passes from the oven to the product Conventional Heating Methods Pass Heat From the Oven to the Product by 3 Mechanisms: 1. Conduction 2. Radiant Convection 3. Convection Radiant (Air flow) Convection Radiant Conduction The top of the product is mainly heated by convection & radiant 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 & radiant 12

13 Conduction in a DGF Oven Conduction in the oven occurs as the heat transfers directly from the hot oven band into the bottom of the dough pieces Oven Band Conduction particularly melts the fat to enhance flow of the dough. This effects product structure and dimension Conduction heats the dough piece from below, changing water into steam. This helps lift the stack height and pushes steam up through the surface for moisture removal 13

14 Radiant Heat in an oven Radiant heat in an oven comes from the hotter metal surfaces, burners flames & combustion gases. The heat then transfers to the product: Radiant heat particularly browns 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 g at exposed points 14

15 Radiant Burners Operated at extremely high temperatures, in order to radiate heat to the product Can be installed at any location in the oven Burner surface temperature 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! Gas Air Spark Exhaust Product Radiant burners are currently being researched 15

16 Natural Convection in an oven Air in the oven chamber is continually circulating as incoming cooler air warms, lightens and rises. It is difficult to manage and control Natural convection air flow inside the oven! Hot oven inner surfaces! Input Cooler air Discharge Cooler air Moving 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 quality 16

17 Forced Convection Ovens Forced 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 17

18 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 Changes with microwave energy are immediate as compared to conventional baking Microwaves help control the moisture and stack height of the product In crackers, the bake time can be reduced from 10-15% 15% to provide a 10-15% through put increase 18

19 Microwave Processing Enhances Coupling to the Product Increase Reaction Rates Shorten Bake Times Manages Product Properties Moisture Stack Height Color Decouples the attributes of moisture and stack height as well as increasing throughput US Patent 5,945,022, discusses processing 19

20 Overview of the Microwave System 20

21 Microwave Assisted Baking 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 Improved product quality by heating the center of the product equally Conventional Heat Microwave Heat 21

22 Radio Frequency (RF) Dryer For Post-Bake Conditioning 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 moisture Higher moisture levels will attract more dielectric energy. Therefore it is a self regulating g moisture control High Moisture = More Energy Low Moisture = Less Energy Conveyor High Frequency Dielectric System Electrodes (+ -) Radio frequency power source 22

23 The Traditional Baking Process Convection Conduction Radiant 23

24 Multi-Media Baking Constants Changing the heat generation systems by altering the 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 24

25 Hybrid Ovens: DGF & Forced Convection Baking Combined DGF (Direct Gas Fired) heat achieves the product structure development at the beginning of the baking process The convection zones are used for moisture removal & color development Convection heat enhances the uniform side to side baking resulting in improved balancing of the product attributes t Due to the even heat in a forced convection zone, temperatures are easier to measure DGF Forced Convection There are hybrid ovens in many bakeries used to produce CRACKER products 25

26 Humidity Control Theory The concept behind using humidity for controlling baking 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 even over a longer portion of the oven (potential ti reduction on checking/breakage; reduce case hardening and burned edges) Future systems will require designing features into the oven to measure humidity in the bake chamber. 26

27 Multi-Media Ovens Consist of: Benefits Convection Conduction Radiant Dielectric These alternative baking sources deliver unique products or attributes by altering heat transfer or baking constants Provides productivity opportunities via the baking process by enhancing the oven with alternative dielectric energy sources Uniform baking and moisture removal is improved Improved control of product thickness and reducing finished product losses Provides the capability of scaling up processes from pilot plant to production 27

28 Michael Mihalos: Mihaelos (Michael) Mihalos is a Senior Associate Principal i Engineer of North hamerican Region Biscuit i R&D Group in Process Development 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 Process Engineering, Process R&D, Technical Services, Manufacturing Development, Pilot Plant, Growth Engineering, Global Biscuit Product Development (PD) and currently in North America Innovation. He is a recipient of the Kraft Foods 2011 Technical Leadership Award for Research, Development and Quality. He spent time in biscuit manufacturing facilities understanding bakery biscuit operations and processing and currently continues to provide 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 process development of new products. He identifies and develops new processes and process technologies in support of the product development business plan and implements Field Ready technologies used in product/platforms. tf He has developed d multiple l process capabilities in innovative technologies implemented this expertise to improve productivity, product quality, and commercialization of new products resulting in 60 + U.S. and International Patent and pending patent applications. He provides process leadership by hosting a Process Development Community Of Practice conference within Mondelēz International organization to share new technologies as well as brainstorming 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 in Jersey City, NJ. Mihalos is a member of the American Institute of Chemical Engineers, Institute of Food Technologists and both a member as well as certified by the American Chemical Society. He is also an alumnus of both Columbia University and Fordham University. Mihalos received a B.S. in Chemistry from Fordham University, a B.S. in Chemical Engineering from Columbia University and an M.S. in Chemical Engineering from Columbia University. He is an alternate for the Biscuit & Cracker Manufacturer Education Committee and presents at the annual technical conference. He also edited the processing section in the 4th edition of Baking Science and Technology Volume II. Mihaelos lives in Pli Palisades Park, NJ. He likes to play basketball,read,and d visit iitmuseums to learn about ancient cultures. 28