![Food Chemistry
HTM301 – Food Science & Production
Version: September 4, 2019
1
photos & illustrations from [Myhrvold, N., Young, C., & Bilet,
M. (2011). Modernist cuisine: The art and science of cooking. C
ooking Lab] unless otherwise cited
What is Stuff?
2
1. Matter
2. Elements
• A species of , which
have the same chemical
characteristics
3. Atoms (unit)
• Smallest unit of an .
• Sub‐atomic particles: (+), ( ), (‐)
4. Molecule (unit)
• Group of ≥ 2 .
• Held together by .
• Sharing .](https://image.slidesharecdn.com/foodchemistryhtm301foodscienceproductionversions-221013151420-b197646d/85/Food-ChemistryHTM301-Food-Science-ProductionVersion-S-docx-1-320.jpg)
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- 1. Food Chemistry HTM301 – Food Science & Production Version: September 4, 2019 1 photos & illustrations from [Myhrvold, N., Young, C., & Bilet, M. (2011). Modernist cuisine: The art and science of cooking. C ooking Lab] unless otherwise cited What is Stuff? 2 1. Matter 2. Elements • A species of , which have the same chemical characteristics 3. Atoms (unit) • Smallest unit of an . • Sub‐atomic particles: (+), ( ), (‐) 4. Molecule (unit) • Group of ≥ 2 . • Held together by . • Sharing .
- 2. • Water • Salt • Baking Soda• H • O • Na • Cl • C • H2O • NaCl • NaHCO3 • H: 1P; 1N; 1e • O: 8P; 8N; 8e • Na: 11P; 12N; 11e • Cl: 17P; 18N; 17e • C: 6P; 6N; 6e Charge & Magnetism 3 • Protons ❤ Electrons • Opposite charges attract ; vise‐versa • Electrons are always in motion • Electrons orbit protons at different distances • Chemical Reactions ‐ encounters btwn atoms and or molecules where: • Electrons are lost/gained/shared. • Some molecules gain/lose electrons more readily than others.
- 3. ie. , . Bonds 4 Type of Bond Power Distribution Strength eg Ionic Between atoms ‐ uneven Strong The bond between Sodium and Cloride in table salt (NaCl) Cl‐ Covalent Between atoms ‐ equal Strong The Hydrogen bonds with Oxygen in Water (H2O) Between Polar Molecules Between entire molecules Weak Molecular cohesion between water molecules Between Non‐Polar Molecules Between entire molecules Very Weak Why molecules of oils move slowly and create viscousness Types of Bonds Energy & Bonds
- 4. 5 • Kinetic energy = movement, motion • Bond energy = electromagnetic Kinetic energy > Bond energy . Heat is energy! Energy & Bonds: Phase Change 6 Requires more energy (heat) melts boils How much heat is needed depends on the strength of the bonds between atoms/molecules. • Low kinetic energy • ∴ Electromagnetic bonds prevail • Can be crystalline • Can be amorphous • Kinetic energy enough to break a fixed structure
- 5. • Electromagnetic forces still influence cohesion • Kinetic energy enough to break a fixed structure, and electromagnetic forces. sublimation Energy & Food 7 http://www.seriouseats.com/2010/08/how‐to‐boil‐water‐faster‐si mmer‐temperatures.html ht tp :/ /w w w .ih m .n lm .n ih
- 8. LM ~1 ~1 & w id ge tF or m at =w ik i • Proteins Denature • Myosin (~122F) • Collagen (~140F) • Actin (~150F) • Collagen Hydrolyzes (160F) • Dehydration • Pectin & Hemicellulose dissolve • Water or Ice • Breaks cell walls • Steams 2x (in‐out ; out‐in)
- 9. Water is Weird 8 High “Latent Heat of Vaporization” melts boils • Low kinetic energy • Electromagnetic bonds prevail • Crystalline • Compared to water: • !Greater volume • !Less dense • Electromagnetic forces still influence cohesion • Molecular Cohesion • Surface Tension • Surprisingly high amount of heat needed given how light water is. Water is ____________, with relatively strong inter‐molecule _________ bonds. Water is Weird
- 10. 9 Temps to Remember 10 http://www.seriouseats.com/2010/08/how‐to‐boil‐water‐faster‐si mmer‐temperatures.html Temp Process 135 140 145 150 155 160 165 170 175 180 185 190 195 200 205 210 212 215 220 225 230 Fructose Starts to Caramelize 235
- 11. 240 245 250 255 260 265 270 275 280 285 290 295 300 305 310 Maillard Really gets going 315 320 Glucose/Sucrose Start to Caramelize 325 330 335 340 345 350 355 Ca ra m el iz at io n Pyrolysis
- 14. The Scientific Method HTM301 – Food Science & Production Version: September 5, 2019 11 Wash, Rinse, Repeat. 12 1. Observe & Question • What do you see/notice? • Based on observation, what are you curious about? 2. Hypothesize • With background research, create a testable explanation. 3. Design an Experiment • Define independent & dependent variables. • Define the control and experimental conditions. • Control for all possible influences, leaving just your testable explanation variable. • Declare a prediction ‐ what results do you expect from your experiment? 4. Run the Experiment • Observe, record, analyze results. Now you try it!
- 15. 13 1. Observe & Question 2. Hypothesize 3. Design an Experiment 4. Run the Experiment FoodSafety & Sanitation Food Science & Production Version: August 29, 2019 1 photos & illustrations from [Myhrvold, N., Young, C., & Bilet, M. (2011). Modernist cuisine: The art and science of cooking. C ooking Lab] unless otherwise cited What Makes Us Sick? • Foreign Particulates • Allergens • Micro‐organisms “Microbes” • Living (?) • Single Cell (Usually)
- 16. • Microscopic (Most of the time) 2 http://w w w .tfw 2005.com /boards/attachm ents/radicons‐custom s/27198494d1291583198‐dcuc‐lex‐luthor‐5.jpg Microorganisms: The Good • In the body • In food production • In the world 3 http://w w w .tfw 2005.com /boards/attachm ents/radicons‐custom
- 21. The Bad (Pathogens) • Worms • Protists • Bacteria • Viruses • Plasmids • Prions 6 ht tp :/ /w w w .t fw 20 05 .c om /b oa rd s/ at ta ch
- 23. g Bad is bad whether in the food or body Three Ways Microbes Sicken 1. Invasive Infection • • 2. Non‐Invasive Infection • • 3. Food Poisoning • 7 Latency Period Who’s in the Legion of Doom? 8 Pathogen Illness Hosp Death Illness Hosp Death Hosp Mort Norovirus 58% 26% 11% 5,461,731 14,663 149 0.268% 0.003% Salmonella, nontyphoidal 11% 35% 28% 1,027,561 19,336 378 1.882% 0.037% Clostridium perfringens 10% ‐ ‐ 965,958
- 24. Campylobacter spp. 9% 15% 6% 845,024 8,463 76 1.002% 0.009% Staphylococcus aureus 3% ‐ ‐ 241,148 Toxoplasma gondii ‐ 8% 24% 4,428 327 E.Coli (STEC) )157 ‐ 4% ‐ 2,138 Listerial monocytogenes ‐ ‐ 19% 255 Subtotal 91% 88% 88% 8,541,422 49,028 1,185 www.cdc.gov/foodborneburden; CS218786‐A February 2011; C DC Estimates of Foodborne Illness in the United States. 2011 CDC Reported Foodborne Illness Report Summary: Top 5 Pathogens Worms 9 • Nematodes (round) • Trematodes (fluke) • Cestodes (tape) • Refridge / Freeze / Heat / UV? Trichinella 10
- 25. Anisakids 11 • Most common in fish… • Wild vs farmed • Closer to land Freeze / Heat / UV? • Effects on humans _______________. Viruses 12 • No beneficial viruses • Three (3) parts • DNA/RNA • Capsid • Envelope (sometimes) • Reproduce only in cells of _________. • Cannot be killed. Must be inactivated. Freeze / Heat / UV ht tp :/ /w w
- 26. w .n ia id .n ih .g ov /t op ic s/ ro ta vi ru s/ Pa ge s/ ro ta vi ru sI llu st ra ti on .a sp x
- 27. Norovirus 13 Protists 14 • Invasive Infections • Eg. • Single‐cell algae, fungi • Protozoa • Shed eggs/oocysts (cysts) • Must be inactivated. Freeze / Heat / UV Toxoplasma Gondii 15• Cell killed through heat/chemicals • Oocysts killed: [email protected]/UVC Toxoplasma Gondii 16
- 28. Bacteria 17 • Aerobic or anaerobic • Reproduce through cell division • Develops spores for protection • Secretes a bunch of various toxins • Strains are hyper‐competitive • Which means: • compete for food • produces by products that are toxic to other microbes. Eg acid & alcohol • Well adapted for survival in environments & hosts Bacteria 18 • Spoilage • Not pathogenic, but signaling • Mostly aerobic • Eg. “Microbial Taint” • Infection • Synthesizes toxins inside you. • Food Poisonings • Bacteria synthesize toxins in the food. You eat the food • Aerobic and anaerobic varieties
- 29. • Eg. Scrombroid Poisoning; Clostridium Perfringes; Staphlococcus Aureus Clostridium Botulinum 19 E. Coli O157:H7 20 21 ht tp s: // w w w .c dc .g ov /e co li/ 20 18
- 31. 7‐ 03 ‐1 7/ in de x. ht m l Bacterial Growth 22 • Geometric / Exponential • Universally, growth rate depends on: • • • • • Moderate influencers of growth: • ________, _________, _________ • because: ____________________________ • A blanket safe/danger zone for all bacteria is a MYTH! But rules of thumb: • Cannot grow above 131F • Grows fastest @ 98.6F
- 32. • Few grow @ >8.0pH; <4.0pH • Grows fastest near 6.8pH 23 Lower pH Lower pH Neutral pH Neutral pH 71.6F 98.6 Low/No Bacterial Growth 24 ht tp :/ /u pl oa d. w ik
- 35. Bacterial Death 26 • Measured in “D’s” • 100% of population reduced to 10% remaining = 1‐ = 1D reduction • 100% of population reduced to 1% remaining = 1‐ = 2D reduction • 100% of population reduced to 0.1% remaining = 1‐ = 3D reduction Q: The canned food industry requires a 12D reduction. What is t he remaining population that is left? A: 100% of population reduced 12D = = 0.0000000001% remaining @6.5D Reduction : ~0.00003% left 27 Salmonella E. Coli Campylobacter Trichinella Safety
- 36. 28 photos & illustrations from [Myhrvold, N., Young, C., & Bilet, M. (2011). Modernist cuisine: The art and science of cooking. C ooking Lab] unless otherwise cited Misperceptions on Sanitation 29 1. Internal, core temperatures. • Contamination is external to the food, Inner, un‐punctured whole muscle is sterile. From the FDA 2009 Food Code: “(C) A raw or undercooked WHOLE‐MUSCLE, INTACT BEEF steak may be served or offered for sale to a READY‐TO‐EAT form if: (1) The FOOD ESTABLISHMENT serves a population that is n ot a HIGHLY SUSCEPTIBLE POPULATION, (2) The steak is labeled to indicate that it meets the definition o f “WHOLE‐MUSCLE, INTACT BEEF” as specified under 3‐201. 11(E), and (3) The steak is cooked on both the top and bottom to a surface temperature of 63C (145F) or above and a cooked color change i s achieved on all external surfaces.”
- 37. Misperceptions on Sanitation 30 2. A Fixed ‘Danger Zone’ • ??? But you’re allowed to cook @130F? • But eggs can be stored at 45F? • But Salmonella starts to die at 120F? 3. Cook to &hold @165F Food C F Time Fish; Farmed Meat; Eggs, broken/cook to order 63 145 15s Injected/Marinated Meats 63 145 3m Eggs other than those cooked to order 66 150 1m Ground fish/meat 68 155 15s 70 158 <1s Poultry; Stuffed Meat; Game 74 165 15s Whole‐Meat Roasts from: 54 130 112m Pork; Beef; Corned Beef; 55 131 89m Lamb; cured Pork Roasts 56 133 56m 57 135 36m 58 136 28m 59 138 18m 60 140 12m 61 142 8m
- 38. 62 144 5m 63 145 4m 64 147 134s 65 149 85s 66 151 54s 67 153 34s 68 155 22s 69 157 14s 70 158 0s Whole Muscle, Intact Beef Steak 63 145 CCC Reheated Food 74 165 15s Any raw food of animal origin 74 165 NA Plant Foods for hot holding 57 135 NA FDA ‐ Specified Cooking Times and Temperatures (2009) Hygiene 31 • Handwashing: You’re doing it Wrong! Handwashing… 32 Cross‐Contamination 33
- 39. Cooking Methods HTM301 – Food Science & Production Version: September 6, 2019 1 photos & illustrations from [Myhrvold, N., Young, C., & Bilet, M. (2011). Modernist cuisine: The art and science of cooking. C ooking Lab] unless otherwise cited What is Cooking? 2 1. Improve flavor, change color 2. Change texture, 3. Reduce chances of foodborne illness, and 4. Increase nutritional value • Maillard Reaction • Caramelization • Pyroliyis • Proteins denature • Caramelization occurs
- 40. • Starches gelatinize • Collagen gelatinize • Cell walls break The application of heat to ingredients to transform them via chemical and physical reactions that: • Safety/sanitation lecture! • Digestibility How Heat is Applied/Transferred 3 • Whether something is cooked is a function of • Time • Temperature 1. Heat transfer is ____________________. 2. Heat must transfer ______________________________. • ∴ thickness, size matters. 3. Heat moves ___________________________________. • Eg ice baths, hot pans, immersion circulators 4. Heat transfers ______________________________. • Eg. diamonds as ‘ice,’ marble counters, wooden spoons, baking stones
- 41. How Heat is Applied/Transferred 4 Radiant HeatConvectionConduction Via waves of energy ‐ electromagnetic ‐ microwaves ‐ heat radiation !!! fastest Direct contact with heat source ‐ pan/metal ‐ stone ‐ the inside of food !!! slow Heat source heats secondary medium that circulates/transfers areas of high energy to lower energy ‐ water/steam ‐ oil ‐ air !!! faster
- 42. 5 Heat: Conduction • Direct contact • Measures • Thermal conductivity • Thermal diffusivity 6 Heat: Conduction • Direct contact• Measures • Thermal conductivity • Thermal diffusivity 7 • Boundary layers, the need for stirring • Natural vs forced convection • Convection and sauce/soup consistency Heat transfer coefficient of common cooking methods Cooking medium Range W/m2*K Example Natural Air Convection 20 Conventional Oven Forced Air Convection 200 Convection Oven
- 43. Water bath 100-200 Sous Vide; poaching; boiling Condensing Steam 200-20,000 Steaming Deep-Frying 300-600 Deep-fat frying Heat: Convection http://ruhlman.com/images/2008/11/17/sous_vide_circulator.jpg Heat: Radiation 8 • Energy Waves • Microwaves and water • Darker objects ____________ radiant heat. Cooking - Flavor 9 1. Heat as a Catalyst • Caramelization (+338F) • Maillard Reaction (+310F) • Pyrolysis (+355F) • Creation/Release of compounds 2. Facilitator of Osmosis!!! • Breaks cell walls • Circulates • Salts, Sugars, Volatiles • Water / fat soluble compounds
- 44. 00 00 Cooking - Color Change 10 Chemical Changes • Caramelization • Reactions • Maillard Reaction Cooking - Texture 11 http://www.seriouseats.com/2010/08/how‐to‐boil‐water‐faster‐si mmer‐temperatures.html ht tp :/ /w w w .ih m .n
- 47. N LM N LM ~1 ~1 & w id ge tF or m at =w ik i • Proteins Denature • Myosin (~122F) • Collagen (~140F) • Actin (~150F) • Collagen Hydrolyzes (160F) • Dehydration • Pectin & Hemicellulose dissolve • Water
- 48. • Breaks cell walls • Steams 2x (in‐out ; out‐in) Temps to Remember 12 http://www.seriouseats.com/2010/08/how‐to‐boil‐water‐faster‐si mmer‐temperatures.html Temp Process 135 140 145 150 155 160 165 170 175 180 185 190 195 200 205 210 212 215 220 225 230 Fructose Starts to Caramelize 235
- 49. 240 245 250 255 260 265 270 275 280 285 290 295 300 305 310 Maillard Really gets going 315 320 Glucose/Sucrose Start to Caramelize 325 330 335 340 345 350 355 Ca ra m el iz at io n Pyrolysis
- 52. Common Cooking Methods 13 Cooking Methods and Heating Methods Cooking Method Dry/Wet Conduction Convection Radiation Baking Dry Heat to center air circulation Broiling Dry Heat to center (Minimal) Infrared Frying (Deep Fat) Dry Heat to center (Minimal) oil circulation Frying (Shallow) Dry Heat to center oil circulation Grilling (Coal) Dry Heat to center Grill marks air circulation Infrared Grilling (GAS) Dry Heat to center Grill marks air circulation Sautee Dry Heat to center Contact with pan Wok Stir-Fry Dry Heat to center Contact with pan Infrared Covered Sautee Dry, then wet Heat to center water vapor circulation Braising Wet Heat to center water circulation Microwave Wet Heat to center steam? Microwaves Sous vide Wet Heat to center water circulation Steaming Wet Heat to center water vapor circulation
- 53. 14 Method – Deep Frying 15 Method ‐Boiling 16 http://mwlfood.files.wordpress.com/2008/11/wok‐cooking‐veggi es.jpg Method - Wok 17 http://chowtimes.com/wp‐content/uploads/2010/08/Wok‐Hei‐ Flaming‐Wok.jpg Method - Wok https://youtu.be/7kuzn2TC1cs 18 Method – Covered Sautee
- 54. 19 Method – Grilling / Roasting 20 Method – Broiling 21 Method - Baking 22 Method - Baking Boundary Layer Desiccation Zone Boiling Zone Conduction Zone
- 55. 23 Method – Braise/Pot Roast/Stew 24 Method – Braise/PotRoast/Stew 25 Method – Sous Vide