Cold pasteurization

Torres, Z. Arias, F. In Irradiation to Control Vibrio Infection from Consumption of Raw Seafood and Fresh Produce, International Atomic Energy Agency Vienna, 2001, 31 pp. Anon. Irradiation (Cold Pasteurization) of Molluscan Shellfish. National Fisheries Institute News Release 99-41. June 25, 1999 (available online at www.nfi.org/hdlines). 

Antimicrobial activity lysozyme, lactoperoxidase (which is exploited as a component of the lactoperoxidase - H202 - thiocyanate system for the cold pasteurization of milk). 

Sweet acidophilus milk differs from conventional acidophilus milk in that a high concentration of viable L. acidophilus organisms is added to cold pasteurized milk and kept cold. At the low storage temperature (4.4 °C) these organisms do not multiply, so the flavor and other properties of sweet acidophilus are identical to fresh fluid milk. The inoculated milk is promoted largely because it contains several million viable L. acidophilus cells per milliliter. 

One of the main interests in food irradiation is that it can be used as a cold pasteurization technique. Many food-borne disease bacteria, including Salmmella, Escherichia coli 0157 H7, and Listeria monocytogenes, are very sensitive to irradiation. Although there are some variations in sensitivity among the previously listed bacteria, a dose range of 1.5-3.0 kGy is sufficient to eliminate all these bacteria as they naturally occur in foods. 

Other demonstration tests using alumina membranes with a mean pore diameter of about 1.4 pm and with a cocurrent flow of permeate (to maintain a constant transmembrane pressure, TMP) to process skimmed milk by the cold pasteurization process have witnessed a flux exceeding 7(X) L/hr-m and 99.7% bacteria removal [Malmberg and... 

Pretreatment of cheese whey by MF has emerged as a necessary step in producing WPl and WPC of varying whey protein content [69]. The MF of cheese whey has two specific applications (1) defatting of whey and (2) removal of bacteria, or cold pasteurization, to produce high-quality WPC or WPl of valuable functional and health or medical properties [70]. 

Nano/microporous cellulose (NMC) prepared after removal of lignin from wood cellulose was found suitable for the development of cold pasteurization" processes acting as a biofilter for cell removal. It was also used successfully as biocatalyst in food fermentations acting as both cell immobilization carrier and as promoter of biochemical reactions, even at extremely low temperatures. The cumulative surface area of the NMC pores was found to be 0.8 to 0.89 m g" as indicated by porosimetry analysis. This surface is relatively small compared with other porous materials such as y-alumina however, using a natural organic material is attractive from the point of view that it is safer for bioprocess applications and is better accepted by consumers. The NMC/immobilized yeast biocatalyst increased the fermentation rate and was more effective at lower temperatures compared with free cells. Furthermore, the activation energy E, of fermentation was found to be 28% lower than that of free cells, indicating that it is an excellent material to promote the catalytic action of cells for alcoholic fermentation. 

Food irradiation. Technology for controlling food spoilage and eliminating pathogens through exposure to ionizing radiation, usually y-rays. The result is similar to conventional pasteurization and is often called cold pasteurization or irradiation pasteurization . 

Both compounds are used in cold pasteurization of fruit juices, wine and beer at a concentration of 120-300 ppm. 

Finally, the intensive investigations in the past 10 years led supercritical CO2 treatment of food to a promising stage by achieving cold pasteurization and/or sterilization of liquids. Now much more knowledge about the mechanisms of microbial inactivation is available. 

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