FROZEN FOOD Xin Teng CBE 555 Presentation

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