Introduction Osmoanabioza microorganism ratio leads to term water activity water content as the bas

Introduction Osmoanabioza microorganism ratio leads to term water activity water content as the basis for the growth of microorganisms in food Combining control activities with other water conservation techniques, measurement and forecast values of water activity in foods Literature
The influence of the water content in food to its perishability has been known since ancient times. Between 15000th and 10,000. 12v heater for car BC our ancestors began to keep a surplus of fish, meat and fruit drying in the wind and sun (Ray, 1992). About $ 8,000. BC introduced many innovations in methods of preserving food. To ensure constant supplies of food, cereals and fruits were stabilized by natural drying and excess meat and fish are protected by smoking and dry salting. Masson and Challet the 1795th The applied the artificial drying of vegetables in preheated room. In the 20th century, innovations are performed 12v heater for car through artificial drying liquid application method of drying rollers and spray as well as freeze-drying. 12v heater for car Methods of food preservation by drying and salting, developed over several millennia, were empirical and more as one art than a science. Quite an interest in the effect of water activity (aw) on the quality and stability of food products 12v heater for car began in the early 1950s (Scott, 1953rd and 1957th). It was caused by empirical and discordant observations between total moisture content and stability of the product. In contrast, 12v heater for car the measured value of water activity (aw) is, in general, in good mutual relationship with the potential for growth and metabolic activity 12v heater for car and has been adopted as a good indicator of the presence of water for microbial activity (Christian, 2000; Chirife, 1995; Lenovich, 1987). As a result of work in the last few years, control aw value is involved in various legal regulations, taking into account the activity of the water more than the total moisture content affects the growth, death, survival, sporulation and toxin production by various microorganisms as well as the adjusting the boundary aw value in food products. Of all the factors that affect microbial growth, death and survival in food, aw influence on vegetative microorganisms and spores is one of those who have been most studied by food microbiologists. . Osmoanabioza
Foods are often conserved procedures that aim to increase them in the osmotic pressure. The separation of solvent and solute a substance permeable membrane occurs pursuit of balancing their concentration. When the membrane is present, the concentration is equated due to diffusion phenomena. In the presence of the membrane also leads to equalization of the concentration by solvent (water) migrates from lower to higher concentrations of solids. The greater the difference in the concentration, the greater the driving force that pushes 12v heater for car solvent molecules to pass through the membrane. If necessary to prevent the equalization of concentration, it would be necessary to apply some pressure in the middle koncentrovanijoj, which opposed the entry of solvent molecules and the pressure 12v heater for car known as osmotic pressure and concentration equalization across the permeable membrane is called osmosis. It is apparent that the osmotic pressure increases with decreasing water concentration. At the same time changing and some other characteristics: increasing boiling point, lowers the freezing point, reduces the equilibrium relative humidity reduces 12v heater for car the water activity etc. The numerical value of the osmotic pressure is directly proportional to the concentration and absolute temperature. This value, for dilute solutions and only for nonconductors, can be calculated from the equation:
In the case of electrolytes, 12v heater for car which are due to dissociation disintegrate 12v heater for car into two or more ions, the value of the osmotic pressure is corrected Vanta Hoffovim isotonic coefficient and . Water is one of the important conditions for the reproduction of microorganisms and their destructive activity. Knowing the effect 12v heater for car of osmosis and micro-organisms for the purposes of water, we can, in a way that changing the substrate (food), making it unsuitable for microbial activity. In fact if we look at the cells of microorganisms that contain water with dissolved substances, it follows that in them, due to a concentration of soluble solids, the government determined the osmotic pressure. In most cell microorganisms government osmotic pressure from 0.3 to 0.6 MPa. If the ambient environment (foodstuff) increase the concentration of solids, so that it is higher in comparison to the concentration in the cell micro-organisms, there will be a loss of water, or to plasmolysis cell microorganisms. With increasing concentration of solids increases the osmotic pressure, the principle of osmosis, water from the microbial cells (cell membrane permeable membrane =) enters the landscape higher concentrations of solids leading to dehydration microorganisms. At a certain point the cells will inasmuch as it runs out of water that will disrupt normal life processes, cease reproduction - which is stopped and microbial spoilage in