1. Freezing effects depend on the food and process

Ice nucleation, growth, and recrystallization can change water distribution and protein structure in muscle foods. The extent and consequences depend on the product, sample dimensions and composition, cooling history at the product core, storage-temperature variation, and thawing method. A freezer set point or the use of liquid nitrogen alone cannot predict crystal size or tissue damage in every food. Findings about fish muscle proteins should not be transferred directly to plant cell walls, all food textures, or nutrient retention across foods.

2. What the Acipenser sinensis study compared

Tan and colleagues studied Chinese sturgeon (Acipenser sinensis), comparing liquid-nitrogen freezing (LNF) with refrigerator freezing (RF) and measuring quality and myofibrillar-protein characteristics during frozen storage. The abstract reports that LNF produced faster freezing, lower free-water content, smaller ice crystals, and less structural damage to myofibrillar proteins. It also reports higher shear force, Ca²⁺-ATPase activity, and total sulfhydryl content, alongside lower total volatile basic nitrogen (TVBN), thawing loss, and disulfide-bond content. These are measured outcomes for the tested fish and comparison protocol; they are not direct measures of every consumer-perceived quality attribute or of nutritional value in general.

3. The -80°C and -110°C treatments were not significantly different

The study also compared LNF at -80°C and -110°C. Its abstract reports no significant differences between those treatments in the measured quality and myofibrillar-protein characteristics, and the authors suggest that -80°C may be more appropriate for this sturgeon application. That conclusion is tied to this species and protocol, not a universal optimum for freezing food. The accessible abstract does not provide every sample dimension and storage-time detail, so this article reports only the comparisons visible in the source record rather than inventing process specifications.

4. Expert perspective: quality measurements are not safety or nutrition guarantees

A review of cryogenic preservation in muscle foods explains that ice formation cannot simply be eliminated and that nucleation, growth, and recrystallization can affect eating quality and nutritional value. It discusses liquid nitrogen and other strategies as areas of development, along with challenges; it does not certify one process as superior for every product. The sturgeon experiment did not test pathogen elimination, safe thawing, vitamin or mineral retention, or commercial performance across species. Freezing is one part of food handling. Safety still depends on appropriate temperature control and handling, while nutritional and quality outcomes need product-specific evidence.

Sources: Investigation of protein structure and quality of Acipenser sinensis frozen by liquid nitrogen / Coexisting with ice crystals: Cryogenic preservation of muscle food—mechanisms, challenges, and cutting-edge strategies