Ultra-high-temperature sterilization

A process for ultra-high temperature sterilization of whey has been proposed. The purpose of the process is to destroy 99.99% of the spores in... 

Adams, D. M. and Brawley, T. G. 1981. Heat resistant bacterial lipases and ultra-high temperature sterilization of dairy products. J. Dairy Sci. 64, 1951-1957. 

Mehta, R. S. and Bassette, R. (1978). Organoleptic, chemical and microbiolgical changes in ultra-high-temperature sterilized milk stored at room temperature. ]. Food Prot. 41, 806-810. 

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. 

Bodie EA, Anderson TM, Goodman N and Schwartz RD (1987) Propionic acid fermentation of ultra-high-temperature sterilized whey using mono- and mixed-cultures. Appl Microbiol Biotechnol 25 434-437... 

Pasteurization of milk apparently does not influence the vitamin content (30). During sterilization of milk (heating to 112 C for 10 min) the vitamin content reportedly decreases by 14%. The mean retention in UHT (ultra-high temperature) sterilized milk was approximately 96% (31). After 6 weeks of storage at room temperature the losses increase to 30%, and the total pantothenic acid losses caused by UHT heat treatment and storage amount to 20% to 35% (32). In dried milk after storage for 8 weeks at 60°C the loss was 18%. The natural vitamin content in fermented milk products was affected only slightly by the fermentation (33,34). 

Ultra-High-Temperature (UHT) Sterile Milk. Rapid increases in the production and sales of sterile, fluid milk in Europe and its entry into new markets around the world merit its consideration in this chapter. Although the gross composition of UHT sterile, aseptically packaged milk is essentially the same as that of its pasteurized counterpart, differences in its properties and minor constituents should be mentioned. 

This product is made by evaporation of water from whole milk under vacuum. Low percentages of sodium phosphate, sodium citrate, calcium chloride, and/or carageenan may be added to improve its stability. The concentrate is homogenized, canned, and then sterilized under pressure at 117° C for 15 min or at 126° C for 2 min. Ultra-high temperatures (130 to 150°C for a few seconds), followed by aseptic packaging, have been used with some success but have found limited commercial application. 

Ultra-high temperature (UHT) treatment involves thermal processing at 138°C-142°C. At this temperature, only 2-3 s, for example, is needed to achieve commercial sterility of milk. After heat treatment, the milk can then be aseptically placed in sterile containers (Garbutt, 1997). The milk can be kept unopened for... 

Ultra-high temperature (UHT) processing A method of sterilizing nulk and dairy products by raising the temperature to 87.8°C for 3 s. 

Pascaud RS, Evans WT, McCullagh PJJ, FitzPatrick DP. Influence of gamma-irradiation sterilization and temperature on the fracture toughness of ultra-high-molecular-weight polyethylene. Biomaterials 1997 May 18(10) 727-35. 

Steam sterilization is the method mostly used to sterilize freeze-dryers. High-quality, ultra-pure steam (water for injection standard USP XXII or PhEur equivalent) is used to achieve a minimum exposure of 121 °C for 30 min or the equivalent temperature-time combination for effective sterilization (Table 2.4.1). This method is easy to validate and is recommended by regulatory authorities as being reliable. The definition of sterilization is a validated process used to render a product surface free of all forms of viable micro-organisms (EN 556-1 2001). According to the authorities, a product or surface is only sterile when a validated sterilization process has been applied (EN 550, EN 552, EN 554, EN ISO 14160 and EN ISO 14937). 

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