Sterilization high-temperature, short-time

High temperature short time (HTST) continuous sterilization, in fermentation, 11 35-36, 45 High temperature steam electrolysis, 13 784... 

LTLT (low temperature, long time) HTST (high temperature, short time) Fore warming (for sterilization)... 

Leviton, A. and Pallansch, M. J. 1960. Laboratory studies on high temperature-short time sterilized evaporated milk. I. Easily constructed eccentric falling ball type bomb microviscometers. J. Dairy Sci. 43, 1389-1395. 

HIGH-TEMPERATURE SHORT-TIME (htst) METHOD. The HTST method is used for two purposes in fruit juice technology to sterilize juices for storage and to precipitate thermolabile protein. 

Simpson, S. G. and Williams, M. C. 1974. An analysis of high temperature/short time sterilization during laminar flow. 7. FoodSci. 39 1047-1054. 

Pasteurization requires considerably less thermal input than does sterilization. Therefore, the thermal losses during pasteurization processing are quite low. However, oxidative losses can be high if care is not taken to deaerate and if high-temperature-short-time (HTST) conditions are not used (80). 

HTST. Abbreviation for high-temperature short-time, refers to processes such as pasteurization, sterilization, etc. 

Polyphosphates improve the sensory quality of many food products. They prevent the separation of butter fat and aqueous phases in evaporated milk, and the formation of gel in concentrated milk sterilized by high-temperature short-time (HTST). They also stabilize the fat emulsion in processed cheese by disrupting the casein micelles and thus enhance the hydrophobic interactions between lipids and casein. Polyphosphates are also used in meat processing for increasing the WHC and improving the texture of many cooked products. The mechanisms involved in different applications depend on the properties of the phosphates and the commodities, as well as the parameters of processing. 

The inhibition of malo-lactic fermentation can be obtained by SO2 (/w30 mg/liter), maintainance of storage temperature at less than 18°C and adjustment of pH to at least below 3.3. Killing or removing the bacteria from wine is a more definite step to stabilize wine against malo-lactic fermentation. Pasteurization and particularly HTST treatment (high temperature, short time -98 C for one second - with rapid cooling) is often used. Sterile filtration has also been used with 0.45 (un membrane filters. 

Early European applications for barrier sheet were in form-fill-seal (FFS) packaging of soft cheese, fruit drinks, jams, jellies, and condiments, and high temperature-short time sterilized milk. FFS packaging (where roll stock is... 

One of the key potential applications of chemometrics in food science is to determine whether or not the food particulates undergoing high temperature/short time (HIST) processing are sterile from post process chemical measurements. Such a determination is possible in principle because both the yield of a chemical reaction and bacterial destruction depend on the temperature/time history. 

The activation energy (E) associated with microbial death is larger than the thermal inactivation of chemical compounds in fermentation broths (see Table 24-4). Thus by sterilizing at high temperatures for short times (HTST), overcooking of nutrients is minimized. 

Higher Fermentation Yields. With a continuous sterilizer, proteins can be sterilized separately from carbohydrates and salts. The residence time at high temperature is short. There is less interaction and degradation of raw materials, resulting in higher fermentation yields. 

A new process has been proposed for ultra high temperature sterilization of whey. The purpose of the process is to destroy 99.99% of the microorganisms in the whey. If very high temperatures are used for short times, this result can be obtained without degrading the protein of the whey, which, besides ruining the food value, gives it a bad taste. 

Fig. 10.15. Heating of milk. 1-3 Pasteurization 1 high temperature treatment, 2 short time and 3 long time heat treatment 4 and 5 UHT treatment 4 indirect and 5 direct 6 sterilization, a Killing pathogenic microorganisms Tubercle bacilli as labelling organism), b c inactivation of alkaline/acid phosphatase, d, d2, d denat-uration (5, 40, 100%) of whey proteins, e casein heat coagulation,/ start of milk browning...

In some applications, a battery pack is needed to go in a sterilizer to meet a specific performance requirement. In such cases, the battery could be exposed to high temperatures exceeding 45°C for a short period of time, which will not affect the battery s performance, reliability, or life cycle. 

Later, Timson and Short started systematic experiments to test the resistance of bacterial spores, and tried to inactivate them completely to obtain a total sterilization. These authors studied the behaviour of spores under a high-pressure treatment with a long residence time at constant pressure in a range of temperature between - 25°C and 95°C. They noted the high insensitivity to pressure of the spores compared to vegetative forms [8]. 

In cases of short-term exposure (e.g., up to a few hours), which would include sterilization by antoclaving (typically 30 min at 134°C/270°C) or paint drying (20 min at 140°C/285°C), decisions made on the basis of maximnm operating tem-peratnre may not be the most appropriate means of selecting candidate materials. For short exposnre times, there may not be any significant level of oxidation or other chemical change in the material that wonld lead to a loss in mechanical or physical properties. However, even short exposnre to high temperatnres can lead to loss of dimensional stability. In some cases, therefore, in which the dimensional stability or stiffness of materials at the maximum use temperature is more important, it may be better to select materials on the basis of the heat distortion temperatnre. 

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