Heating preservation

Food processing firms producing heat-preserved, frozen, dehydrated, or chemically preserved foods may be classified by their finished products. Companies may be further grouped based on whether they process raw materials into ingredients, such as in poultry and meat processing plants, or whether they take these ingredients and convert them to ready-to-eat consumer products. 

If food can be heated quickly to a temperature of I3I°C a lethaUty equivalent to 6 min at I2I°C can be accumulated in 36 s. This rapid heating and cooling of hquid foods, such as milk, can be performed in a heat exchanger and is known as high temperature—short time (HTST) processing. HTST processing can yield heat-preserved foods of superior quahty because heat-induced flavor, color, and nutrient losses are minimized. 

Acid foods generally require the simplest equipment for heat preservation. The food can be heated to 100°C and filled hot into suitable containers. The containers are sealed, inverted to sterilize the closure, held at the filling temperature for a short time to ensure that the package is thoroughly heated, and then cooled. Tomato sauces, jellies, fmits, fmit juices (qv), and pickles are routinely preserved in this fashion. 

North wall 240 mm clay brick+100 mm polystyrene heat preservation layer+240 mm clay brick 150... 

North roof 50 mm steel plate+100 polystyrene heat preservation layer+50 mm steel plate 108... 

North wall 5 mm coated steel sheet+100 mm polystyrene heat preservation layer+5 mm coated steel sheet 126... 

Chai L., Wang B., Liu M., Wu Z., Xu Y. (2014). Dual-roof solar greenhouse—a novel design for improving the heat preserving capacity in Northern China. Natural Resources, 5(12), 681. 

Acid dye affinity, 19 759 Acid dyes, 9 184-186, 189-190, 215-216, 226, 243 26 395-396 anthraquinone, 9 301, 327-329 azo, 9 389-394 Acid dyestuffs, 9 223 Acid extractants, 10 750 Acid fixing reactive dyes, 9 478-481 Acid foods, heat preservation of, 12 80 Acid functional polyesters, 10 402 Acid gas constituents, 12 376-378 Acid gases, 10 612-613... 

Natural heat preserves the life of man. If his body lose its natural heat his life has come to an end. 

H.A. Leniger and W.A. Beverloo, Progress in Heat Preservation, Dechma Mono-grafien Band 63, 1963. 

Thermal Preservation Technology. The heat preservation of foods can he accomplished by various combinations of heating limes and temperatures, depending on the number and type of heat-resistant spores present, the composition of the food, and the physical characteristics of the food and package. 

Low acid foods have a pH > 4.5, require steriliz.aliun at temperatures above 100 C. and thus require treatment in pressure vessels. Heat preservation processes above 100 C can he carried out in batch or continuous heat-exchange equipment. 

Intermediate moisture foods are in the aw range of 0.90 to 0.60. They can achieve stability by a combination of aw with other factors, such as pH, heat, preservatives, and Eh (equilibrium relative humidity). 

Thus in contrast to heat preserved foods HP-preserved foods retain their uncooked" ( fresh ) status. 

Dr. Penington, who devised a method of heat-preserving milk (prior to pas-... 

The three-dimensional helix is homogeneous and is of permanent distortion. Thus, the staple has a soft, high fluffiness, good rebound, and good heat preservation properties. The... 

The term pasteurisation takes its name from the great French scientist Louis Pasteur. Prior to his work heat preservation of some foods and drinks was already employed and had been for some time. However, this was carried out on an anpirical basis and it was Pasteur who was able to elucidate the scientific reasoning behind how it works. 

In this micro sintering experiments laterite ore should be crushed to the needed granularity firstly less than 8mm accounted for 90%. The reducing agent coke was screened to 200 mesh and the proportion is about 80%.. Conduct four groups totally the additives fluorite content are 0% and 5%, respectively, the maximum temperature is seted of 1050 ° C (alkalinity to 1), and 1200 ° C (alkalinity to 2). When the furnace temperature up to the maximum temperature of the test requirement, the samples should be cooled to room temperature in the furnace after heat preservation for 10 min. A small amount of the sample was pulverized after the experiment for XRD analysis and then to determine the compressive property. 

The important measures to reduce the temperature difference loss are to improve the design of the interchanger, increase the heat-transfer coefficient and areas, prevent the leak between shell-side baffles and crust and to strengthen the heat preservation system. 

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