Cooking freeze-drying

Raw foods were freeze-dried and analyzed for carbon isotopes using mass spectrometry. Cooked foods were prepared following historic recipes, then were freeze-dried prior to analysis. For the trace element analysis, foods (both raw and cooked) were wet ashed using nitric acid in Teflon lined pressure vessels and digested in a CEM Microwave oven. Analysis of Sr, Zn, Fe, Ca and Mg was performed using Atomic Absorption Spectrometry in the Department of Geology, University of Calgary. 

Rapid-acting cytotoxin capable of producing either incapacitating or lethal effects. It is one of seven enterotoxins obtained from bacteria (Staphylococcus aureus). It is a white, fluffy solid that is water soluble and heat stable (not destroyed by cooking or freezing). Aqueous solutions are "probably stable." It resists chlorine used in municipal water systems. As a freeze-dried powder, it can be stored for more than a year. 

Shibata, T. Freeze-drying of cooked rice. Jpn. Kokai Tokyo Koho, 1991... 

These potent natural toxins are tasteless and odorless, and contaminated seafood appears to be completely normal. They are not destroyed by cooking or by food preservation (e.g., freezing, drying, or salting). In addition, these toxins are refractory to the action of human digestive enzymes, and there are no antidotes against their biological activity (Schantz, 1973). 

Frozen materials should be stored at —20°C, fruits and salad vegetables at around 4°C, and canned foods at room temperature. Powdered and freeze-dried materials should be stored in the dark in their original containers. Storage of fresh materials should preferably not exceed 3 days. After the initial preparation (see below), fresh or cooked materials can be conveniently stored at -20°C for a short time prior to extraction. 

The process of freeze-drying food uses freezing and sublimation to preserve food for long periods of time without refrigeration. The goal of freeze-drying food is to remove all of the water from food without using heat. This leaves a completely dry product that has not yet been cooked. Hot water can later be added to rehydrate the food and produce an edible, freshly cooked meal. 

Diffusate powder prepared by freeze-drying dialyzable water-soluble solutes from beef is undoubtedly the best precursor mixture for producing "meaty" odor and flavor since it is these ingredients that are largely responsible for the flavor of cooked meat. 

The green herb is used for flavour during cooking or prior to serving. The dried herb is inferior in quality compared with the freeze-dried or frozen ones. The major flavour component is anethole, which gives the herb the odour and flavour of anise. 

Mussels (Mytilus edulis) were fished in the Dutch Waddensea. They were cooked under pressure (at ca. 120°C) for 30 s and the shells were removed. Then they were instantly deep-frozen (liquid nitrogen) and stored at a temperature below -28°C. Some 550 kg material was freeze-dried during 20 h and ground in a stainless-steel mill which could have caused some contamination with Fe. Upon freeze-drying, the material have lost 73.5% of its mass. 

The effects of variation in meat oonposition on mutagenicity of cooked product were examined in reconstituted beef patties. Patties of variable water and fat content were prepared fron freeze-dried meat. Appropriate amounts of distilled water were added back to the meat for the variable-water-content experiment. Defatted meat was prepared by petroleum ether extraction of freeze-dried material in a Soxhlet apparatus. Petroleum ether was removed m vacuo and the remaining oil was used to reconstitute the meat sanples/ vhich were also reconstituted to their original water content. Reconstituted meat samples had the coitpositions indicated in Figures 4 and 5. 

Figure 5. Effects of variation of initial fat content on mutagenicity of ground beef. Samples are fried at 200 °C for 6 min per side and the basic fraction is tested for activity in the Salmonella mutagenesis assay. An amount of water equal to that removed in freeze-drying was added to each sample. Graded amounts of the extracted fat were added to the reconstituted samples before cooking.

Osmotic dehydration does not allow a product of low moisture content to be considered shelf stable. Consequently, an osmotically treated product is further processed by air, vacuum, or freeze-drying methods. Osmotic pre-concentration followed by fluidized bed drying of potato pieces to produce dehydrated quick-cooking potato was studied by Ravindra and Chattopadhay [12]. They found that a solution of 50%... 

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