Each has its specific applications.
Quality fried onion rings freezing can be accomplished by either mechanical or cryogenic freezing. In each case the quality is commercially the same. The shrink loss will be minimal provided the onion rings, either natural or fabricated, are introduced into the freezer immediately upon exit from the "fryer".
A cost comparison (Table 3) indicates that the "cost to freeze" fried onion rings in a mechanical system is much less than in a liquid carbon dioxide or liquid nitrogen freezer. The capital cost and organizing information was obtained from an onion ring freezing plant. The data was taken from their last years operating cost analysis.
Another cost comparison (Table 4) indicates the "cost to freeze" hamburger patties in a mechanical system is much less than that experienced in a liquid carbon dioxide or liquid nitrogen freezer, In Analyzing various studies regarding hamburger patties using liquid nitrogen or liquid carbon dioxide the referenced tests indicate that minimal losses occur when the hamburger patty is frozen in less than 8 minutes from 40 degree F. to O degree F. in a -80 degree F. carbon dioxide atmosphere. There have been quite a few tests that indicate hamburger patties can be frozen in IQF. Fluidized Freezers within 6 to 8 minutes with air at -35 degree F. to -40 degree F. with a minimum of so-called freezer. burn or greying of the edges of the patty. The comparisons offered have disregarded the "shrink" factor as mechanical systems can be designed to provide equal if not better performance than cryogenic system with regards to shrink and quality,
