A supplementary microbiostatic control measures is to ensure adequate cooling rates of packaged products to minimize potential for Bacillus cereus growth. The warm sealed product may be commercially sterile as any surviving microorganisms may not be able to grow. When combined with low pH in the product, e.g. The product is sealed at the packaging temperature and chilled for storage/distribution purposes afterwards. Such process can be done in a continuous flow system or in batch processes. Warm sealed packaging: The application of heat (80 to 95 ☌) to a solid end product in connection with the packaging process, for instance to maintain the product at a viscosity suitable for packaging. When applied at higher temperatures, the treatment is often referred to as More effective when applied in combination with other microbiological control measures. Pressures and temperatures able to destroy cells. Implosion of microscopic bubbles generates spots with very high Ultrasonic: The application of high intensity ultrasound (18-500 MHz) that cause cycles of compression and expansion as well as cavitation in microbial cells. Will be heat-stressed and become more vulnerable to subsequent microbiological control measures. A general reduction of log 3-4 can be expected. Thermization: The application to milk of a heat treatment of a lower intensity than pasteurization that aims at reducing the number of microorganisms. Ripening (ageing): Ccheese ripening and subsequent PH reduction kills harmful bacterea Due to the inability to penetrate in-transparent substances, the technology is only effective against surfaces, for instance, in the removal of biofilm and can therefore prevent cross contamination packaging material, equipment and water) high intensity broadband light pulses of wavelengths in the ultraviolet, visible and infrared spectrum (~20,000 times sunlight) to destroy microorganisms. Pasteurization: Heating milk and the number of any pathogenic microorganisms to a level at which they do not constitute a significant health hazard. Synergy in combination with heat treatment. Normally, a pore size of ~0.6-1.4 µm is sufficient to separate most bacteria. Microfiltration: Removal of microbial cells, clumps and somatic cells by recirculation over a microfilter. High-pressure treatment: Application of high hydrostatic pressures to irreversibly damage the membranes of vegetative cells. The treatment destroys cells by establishing pores in the cell walls due to the build up of electrical charges at the cell membrane. Examples are microwave energy (thermal effect), rdio-frequency energy (non-thermal effects) or high electric field pulses (10 - 50 kV/cm, nonthermal effects). Usually in cheesemaking the microbiological control measure applied by choice of starter cultures.Įlectromagnetic energy : Electromagnetic energy results from high voltage electrical fields, which alternate their frequency millions of times per second (< 108 MHz). Competition for nutrients and production of antimicrobial substances (such as nisin, other bacteriocins and hydrogen peroxide). Products manufactured using this method are microbiological stable at room temperature.Ĭompetitive bacterea: Reduction in the number of undesirable microorganisms by lowering the pH. Sterilization: Heating at high temperatures for a time sufficient to render milk or milk products commercially sterile. Most efficient against microbial cells of high density, especially bacterial spores and somatic cells Pasteurization and other heat treatments of milk such (sufficient time/temperature combinations) that they practically eliminate specific pathogens.Įxamples of typical microbiocidal control measures include the following:Ĭentrifugation / bactofugation: The removal of microbial cells of high density from milk using high centrifugal forces. Keeping Quality - to improve the keeping quality of milk and milk products. Pasteurization - destruction of all pathogenic (harmful to health) Bacteria The process of pasteurization was named after Louis Pasteur who discovered that spoilage organisms could be inactivated in wine by applying heat at temperatures below its boiling point. Delta T calculation for plate heat exchangers.
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