FROZEN FOODXin Teng

CBE 555 Presentation

11.4.2013

www.healthychoice.comwww.eatyourbest.com

Overview• Facts and Definition• Types• Processing Technology• Healthy, or not? – nutrients• Interesting

https://www.google.com/search?q=frozen+food+is&espv=210&es_sm=119&source=lnms&tbm=isch&sa=X&ei=3od2UrLHMoau2gXx9YHAAw&ved=0CAkQ_AUoAQ&biw=1163&bih=554#es_sm=119&espv=210&q=frozen%20food&tbm=isch&facrc=_&imgdii=_&imgrc=IkuqTlf66jk0xM%3A%3BV3TyHBG4OoWPVM%3Bhttp%253A%252F%252Fhealthontrack.info%252Fwp-content%252Fuploads%252F2011%252F09%252Ffrozen-food.jpg%3Bhttp%253A%252F%252Fhealthontrack.info%252Ftag%252Ffrozen-food%252F%3B1600%3B1062

Fun facts and definition

• Food preserved by a freezing process and stored in a

freezer before cooking or consumption

• Mintel research• 94% U.S households use frozen or refrigerated meals

• National Poll by Nestlé USA • 25% confessed – having passed off frozen meals as their own

culinary creation• 64% said – their meals often only consist of frozen food• 44% said – often find an U.F.O in their freezer, Unidentified Frozen

Object

What are the different kinds?• Categories:

• Frozen breakfast• Frozen meals and dinner• Vegetables• Bakeries and desserts• Pizza• Fruit and juice• Meat and Seafood• Ice-cream

• Or: • Ready to eat upon thawing• Ready to eat without thawing• Cooked, need to be reheated• Raw, need to be fully cooked

Processing Technology

• Food is frozen for preservation at cold place

• Clarence Birdseye: Flash-freeze• flash-frozen under pressure

• Different flash-freeze systems

• Mechanical

• Cryogenic

Process Technology

• Pre-freeze treatment: blanching

• Boiling water or steam immersion for 3-10 minute

• Inactivate metabolic enzymes

• Prevent enzyme-mediated oxidation reactions

• Eg. Cauliflower and spinach

Lyco Rotary Drum Blancher

Multi-plate freezing system

Nutritional aspects

• Frozen meats:

• To slow and prevent post-mortem changes that may adversely

affect microbiological safety, sensory quality and nutritional value

• Freezing does not have great influence on nutrient level of meat

but…

Nutritional aspects• Frozen vegetables and fruits

• Small difference in mineral and fiber level• Difference in vitamin level

• Timing• Post-harvest treatment: minimize the time to minimize the loss

Nutritional Aspects

• Frozen Pizza• Frozen fries• Frozen meals(some)

• Frozen fruit and vegetables• Frozen meat and seafood• Frozen meals(some)

Bonus: What kind of process do industries use to make yogurt melts?

Freeze Dried Food• Examples:

• Instant coffee: How instant coffee is made• Meat and vegetable for camping, military and space stations• Pet food• Fruits-just add milk• And yogurt melts!

• Sublimation of ice to water vapor• Process

• Food is frozen first, formation of ice crystals within food• Exposed to vapor partial pressure (typically -60 Celsius) much below the

equilibrium vapor pressure of ice at the temperature of the material using a condenser unit-primary sublimation

• Vacuum is maintained in the freeze drying chamber- to remove air and other non-condensable gases

Questions?

• Thank you!

• Frozen Food Science and Technology, Judith A. Evans, 2009