frozen food xin teng cbe 555 presentation 11.4.2013
Post on 16-Dec-2015
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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
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)
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
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