Abstract: Direct contact cooling or freezing of foodstuffs immersed in or sprayed with a low freezing temperature liquid preferably comprising a mixture of a chlorofluorocarbon (CFC 113) and perfluorohexane (C.sub.6 F.sub.14) minimizes migration of toxins in the heat transfer liquid to the foodstuffs.
Abstract: Ultra rapid freezing of thin wall containers, preferably plastic bags or bottles, of blood plasma by direct contact with a low freezing temperature liquid mixture of a chlorofluorocarbon (CFC 113) and at least one of a group of fluorocarbons minimizes migration of toxins in the heat transfer liquid to the plasma and improves the percentage yield of blood soluble protein fractions extracted from the frozen plasma in a subsequent freeze drying process.