Which quick-freezing process incorporates very low temperatures with liquid nitrogen or carbon dioxide?

Which quick-freezing process incorporates very low temperatures with liquid nitrogen or carbon dioxide?

• A. Air blast freezing
• B. Cryogenic freezing
• C. Plate or contact freezing
• D. Immersion freezing

Answer: (B)

Rapid heat removal using extremely low temperatures is the hallmark of cryogenic freezing. By using liquid nitrogen or carbon dioxide, foods are brought to very cold environments (LN2 around −196°C or CO2 around −78°C) very quickly, often through spraying or direct contact. That huge temperature difference pulls heat out of the product in a blink, causing water inside to freeze into very small ice crystals. Small crystals cause less cellular damage, helping maintain texture, moisture, and flavor after thawing. Other methods rely on colder air, metal plates, or submerging in a cooled liquid, but they don’t reach the ultra-low temperatures of cryogenics, so the freezing is slower and ice crystals tend to be larger, which can affect quality.

Rapid heat removal using extremely low temperatures is the hallmark of cryogenic freezing. By using liquid nitrogen or carbon dioxide, foods are brought to very cold environments (LN2 around −196°C or CO2 around −78°C) very quickly, often through spraying or direct contact. That huge temperature difference pulls heat out of the product in a blink, causing water inside to freeze into very small ice crystals. Small crystals cause less cellular damage, helping maintain texture, moisture, and flavor after thawing.

Other methods rely on colder air, metal plates, or submerging in a cooled liquid, but they don’t reach the ultra-low temperatures of cryogenics, so the freezing is slower and ice crystals tend to be larger, which can affect quality.