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56 Cards in this Set

  • Front
  • Back
NLEA
-National Labeling and Education Act of 1990
-Mandated numerous changes in food labeling
Food Labels
1. Name
2. Net weight
3. Name & Address of manufacturer/packer/distributor
4. Ingredients list
5. Grades
6. Nutritional Info
7. Shelf Life data
8. IF standard of identity - clearly labeled
9. IF requires addt'l ingredients/further prep
Imitation
Used when a product resembles a standardized product but does not have an equal nutritional value
Protein Hydrolysates
Source of protein must be identified, unlike past which use a common name
Sulfites
All foods that are sulfited must state the sulfiting agent
Food Label Grades
-USDA grades all foods except seafood
-State health agencies authorized by FDA may grade
- Inspection sticker (safe/wholesome/sanitary)
-NOT mandatory, not dependent on nutritional quality
Transfat
Listed on label as of January 2006
DV
Daily Values, % based on 2000cal diet
Saturated Fatty Acids
-Completely saturated with H atoms
-Solid @ room temp
Unsaturated Fatty Acids
-Contain double bonds btwn adjacent C atoms (Mono, Poly)
-Lower melting point, Liquid @ room temp
-1+ double bonds oxidize more readily --> rancidity
Factors Accelerating Fat Oxidation
1. Heat
2. Certain wavelengths of light
3. High Energy Radiation
4. Certain metal ions
Maillard Reaction
-Reducing sugar and a free amino acid
-Onion, Bread Crust, Soda
Caramelization
-Removal of water from the sugar molecules by heat, changes structure of sugar
Major Causes for Food Spoilage
1. Microbial
2. Physical
3. Chemical
Basic Food Preservation
-Pasteurization: inactivates many microorganisms using heat
-Fermentation: lowers pH, inhibits MO
-Pickling/Salting/Sugaring: lowering pH and/or Aw inhibits MO growth
Heat Transfer
1. Conduction
2. Convection
3. Radiation
4. Combination of above

-Destruction of MO based on time-temperature relationship
-Pathogenic spore-forming bacteria are target
-C. Bot = very heat resistant
Conduction-Convection
collision of hot particles with the cooler ones
-changes in food (juices in large pieces of meat) --> convection
Convection-Conduction
circulation of warm molecules
-more effective
-less time to reach target temp
-rapid heating
-changes in structure (gelitization of starches) --> conduction
Radiation
-transfer of energy by electromagnetic waves
-fastest method of heat transfer
-transfers heat directly from source to food
-contact surface reduces amount of heat
D Value
Time in mins @ a specific temp to reduce the # of MO by one log cycles
Z Value
Temp required to decrease the time necessary to obtain one log cycle reduction of cell #s to 1/10 of the original value
Processing of Low Acid Foods
-Exposure to a temp for a period equal to # D values based on acid level of food
- pH 7-4.5
-High Temp Processing = 240-250F
Processing of High Acid Foods
-Boiling water processing = 212* F
Still Retort
-containerized and heated in a steam environment w/o agitation
-Temps over 250* F may burn product
-Heating time usually 30-45 mins
Agitating Retort
-Agitated during cooking
-Allows high temp, convection heating
-Reduces time to reach final temp (10-20% of still retorts)
Hydrostatic Retort
-Cans flow continuously
-Uses hydrostatic heat to control pressure
-Agitating system
Canning
1. Pretreatment (clean, cut, inspect)
2. Blanching (steam or water)
3. Filling & Creation of Vacuum
4. Sealing the cans (hermetic seal, anaerobic inside)
5. Processing (retort @ 250F @ 15psi up to 2 hrs)
6. Cool the cans
7. Pack the cans in cases
Vacuum in Cans, WHY?
1. Minimize swelling
2. Minimize oxygen from headspace
3. Prevent buckling during retort
Vacuum in Cans, HOW?
1.Add hot food to container and seal
2. Use cold product but pass through a steam box uncovered
3. Pull a vacuum manually
4. Steam Jet vacuum
Liquid in Cans
-Brine/Sugar for Veggies
-Sugar/Syrup for Fruit
-Liquids speed up retort due to convection
-Solid packed foods heat through conduction -->slower
High Temp - Short Time (HTST)
-Liquids and Purees
-280-300*F for 15-45 secs
-May use culinary steam to heat
-Kills bacteria and their spores, added steam removed
-Product filled into aseptic pack and sealed (Aseptic Fill)
Hot-Fill-Hold
-High acid, low pH foods
-170-190*F for 25-30 mins
-Kills all vegetative cells
-Spores not killed
Sous-Vide
-French, "under vacuum"
-Food packaged under vacuum and refrigerated till used
-PROBLEMS: C. Bot outgrowth
-Only allowed under FDA license
Dehydration
Almost complete removal of water.
-Control of environmental conditions: humidity, temp, air flow, sanitation
-Moisture 1-5%, Shelf life 2+ yrs
Quality Defects in Dehydration
-Loss of flavor compounds & nutrients
-Browning
-Texture Collapse
-Liquid Oxidation
-Case Hardening
Objectives of Dehydration
-Prolong storage
-Preserve quality characteristics
-Reduce product volume
-Decrease distribution costs
HT - Heat Transfer (Dehydration)
Transfer of heat from one body to another by conduction, radiation or convection
-Moving of hot air
-Heat transfer to water on surface
-Water on surface gains heat energy and evaporates forming a water vapor
MT - Mass Transfer (Dehydration)
The movement of a constituent of the food from one location to another. Usually involves a change of state.
-Removal of water vapor by cooling air
-Water from interior move to the surface by osmosis and diffusion
4 Factors affecting Heat & Liquid transfer during Drying
1.Surface Area: greater surface area, faster drying
2.Temperature: greater temp, faster drying
3. Humidity: Higher humidity, slower drying
4. Atmospheric Pressure: Lower pressure, lower temp
Drying Curve
-Lose water at a changing rate
-Water lost rapidly from surface
-Outer layer creates insulation barrier preventing rapid heat transfer
-Reaches normal equilibrium in relative humidity
-Rapid to slow loss of water (graph)
Solute Concentration & Binding Water
-high in sugar or other solutes dry more slowly

-Free water is removed
Drying Techniques
*Sun - H2O removal using heat of sun
*Hot Air - hot air to evaporate H2O
*Spray - atomized particles of a fluid are dried in contact with heat
*Fluidized Bed - steam of hot air on mess beds
*Vacuum - H2O removed under pressure
*Drum - passed btwn 2 heat rollers
*Freeze - frozen and sublimed
Refrigeration
Process of removing heat from a confined space and objects within that space for the purpose of reducing/maintaining the temp below the surrounding atmosphere
History of Refrigeration
- 1850's in the US
- 85%+ of our food is refrigerated
- home refrigerator WWII
- Gentle/Short time preservation
- 40-45*F
- MO grow more rapidly above 50*F, but as long as H2O till 15*F (slows down, doesn't stop MO)
Cooling Capacity of Ice
- Greatest point when melting
- 1lb of ice melts, lowers temp of 24lbs of food by 6*F
Refrigeration: How it Works
- Refrigerant, Expansion Pipes, Compressor, Condensor
- Refrigerant liquid to gas
- Liquid gains heat energy, gas changes to liquid it loses heat energy
Requirement of Refrigerated Storage
- Low temp
- Air Circulation
- Humidity Control (80-90%)
- Modified Gas Atmosphere

- Factors that can affect:
Insulation, Door Opening, Quantity of hot product added, Refrigeration rate of food
Freezing
- 1920, Clarence Birdseye
- 32* F, solutes lower freezing point
(concentration increases, freezing decreases)
- Free Water freezes first

- The addition of 1 mole of any nonionic substance to 1L of H2O lowers the freezing pt by 1.885*C
- Processors freeze at 0*F (must be maintained during transport and storage)
Preservation effect of Freezing
- Spoilage is result of high AW
- Temps lower than 32*F --> crystallization and freezing
- Crystalized water is not available to MO
Slow Freezing
- H2O molecules start crystallizing
- Time to migrate to ice crystals already formed, making large crystals
Quick Freezing
- Ice crystals made in their tracks, no time to migrate
- Make small crystals out of local water molecules
- Temp must fall 32-25*F in 30 mins

1. Smaller ice crystals
2. Soluble components move to a lesser degree
3. Chem & Bio Rx rates reduced

- -76*F all detectable H2O frozen
Freezing Methods
1. Air Blast
2. Fluidized Bed (Peas)
3. Dehydro
4. Plate (packaged, btwn two plates)
5. Liquid (Nitrogen)
6. Slow
7. Slush
8. Scraped
9. Sharp
10. Pressure plate
Temperatures Abuse
-Must be thawed properly to avoid extended exposure to ambient temps. Drastic changes in quality can occur in short period of time.

- Enzymes and/or microbial induced changes can occur
Changes during Storage of Frozen Foods
*Physical: crystallization, loss of volatiles, structural breakdown
*Chemical: protein denature, lipid oxidation, oxidation, color and flavor loss
*Enzymatic
*Microbial (rare)
Chemical Changes during Freezing
*Enzymes/MO in fruits & veggies slowed down, not destroyed, though gradual decline
*Can cause color and flavor changes, loss of nutrients
Textural Changes during Freezing
*Ice crystals formed cause the cells walls to rupture
*Softer texture
*Most noticeable in fruits & veggies w/ high water content

Factors: rate of freezing, fluctuating temp, moisture loss