Freezing of fish

What is the "critical freezing zone" in food freezing?

• The range where food changes colour due to oxidation

• The temperature range where the core of the food reaches 0 °C

• The temperature range during which most of the water in food turns into ice

• The point at which food begins to thaw

Why is it important to pass through the critical freezing zone quickly?

• To prevent loss of vitamins

• To minimize the formation of large ice crystals

• To increase microbial growth

• To enhance nutrient absorption

Which freezing method is most effective at avoiding damage in the critical freezing zone?

• Fast freezing using blast or cryogenic methods

• Slow air freezing

• Thawing before freezing

• Storage at ambient temperature

Slow freezing typically causes which of the following outcomes in fish?

• Reduced cooking time

• Formation of microscopic ice crystals

• Minimal protein denaturation

• More cellular damage and higher drip loss upon thawing

What is the common method used to achieve fast freezing in the food industry?

• Storing at room temperature

• Using cryogenic freezers with liquid nitrogen

• Drying in a cabinet

• Packaging with carbon dioxide

Which method is more suitable for preserving high-value, delicate products like sashimi-grade fish?

• Slow freezing at –20 °C

• Sun drying

• Fermentation

• Cryogenic freezer with liquid nitrogen