METHOD OF PRESERVATION OF BIO-DETERIORATION

Method of preservation is importance of food preservation is to increase food shelf life. Most of the time, the growth of microorganisms that cause spoiling or disease is what restricts how long a food can be preserved, hence the main focus of most preservation procedures is to slow or stop this growth.

LOW TEMPERATURE

2.Cooling and freezing
While cooling is a more generic phrase used to describe the decrease of a food's temperature, chilling may be defined as the process that lowers the food's temperature to between a safe storage temperature of 0 to 5 C. Foods that are chilled rather than frozen can pose a bigger threat to public health since refrigeration slows but does not completely eliminate the food's microbiological and chemical degradation. The shelf life of most chilled foods is limited by microbial growth; even modest growth rates that take place under cold settings can eventually lead to microbial levels that could harm the meal or provide a possible threat.

  1. Freezing
    Food that has been frozen does not become sterile. Despite the fact that freezing can lower levels of specific vulnerable microbes, this does not significantly affect the food's overall microbiological quality. However, all microbial activity ceases at commercial freezing temperatures (between 18 and 24 C), and the amount of time that food can be stored depends on other conditions. The present living bacteria will develop and multiply when a frozen food is defrosted, it is crucial to remember

DRYING AND WATER ACTIVITY CONTROL


Many common foods, such as grains, legumes, and rice, are available in dried form. As long as they are kept dry, they will remain edible for a long time. Reducing the amount of water in food that is available to microbes is one method of slowing or halting development because all bacteria require water to grow

Foods that are dried can be produced using a variety of drying techniques . The food and its intended usage will determine the method and packing format to utilize. Each of the aforementioned techniques can lower the aw level to almost 0.3, eliminating microbial and enzymatic degradation processes.

The traditional use of sugar to create an osmotic pressure gradient to lower the levels of aw in meals. The amount of water in some foods, such jams and marmalades, may be rather high, but most of it is "tied up" or "bound" (i.e., the food has a low water activity) by the sugar and pectin in the jam, making it unavailable to the microbes for use.

CHEMICAL PRESERVATION


Chemicals called preservatives are added to food to stop bacteria growith and chemicalreactions. in the UK. and EU, only a small number of preservatives are legalto use, and there are strict usage restrictions, several preservatives are only permitted in certain types of food re.g., nitrate and nitrite salis to specific meat, cheese, and fish products:

CURING
In order for something to be preserved, the water that would normally be available for microorganism growth must be chemically or physically bonded to the curing agent and not be accessible to the microorganism. For instance, salt accomplishes this by forming ionic connections between the sodium and chloride ions in the salt and the polarized hydrogen and hydroxide ions in the water.
While nitrite also has preservation properties and helps to the distinctive color of these dishes, salt has preservative and flavor benefits in cured meat products.

PICKLING
Although the term can occasionally be used to refer to salt preservation, this term most frequently relates to the preservation of foods in acid or vinegar. While yeasts and molds require significantly higher levels of acidity (pH 1.5-2.3) to prohibit growth, the majority of food poisoning bacteria, such as C. botulinum, stop developing at pH values below 4.5, the lowest level obtained during the pickling process.

SMOKING
This is yet another conventional food preservation technique that uses chemicals to maintain the food. Meat hanging on a fireplace or chimney to dry out is where the practice of meat smoking originated. The meat is partially dried, which helps with preservation in and of itself, but the polyphenol compounds in the smoke have direct preservative and antioxidant properties as well as give the meal a distinctive flavor.
An example of a food where brining is combined with smoking to produce a finished product with a longer shelf life when refrigerated is smoked salmon. Microbial development is inhibited by three preservation techniques: brining, smoking, and low temperature. Smoked food is typically packaged in translucent shrink-wrapped plastic film

FERMENTATION

FERMENTATION
fermented foods, preferred microorganisms are permitted or encouraged to grow in orderto produce a palatable, safe, ano relatively staste product. The microorganisms prevent or relaro the grout of undesirable spollage or pathogenic organisme and may also inhibit undesirable chemical chenges. Permentation represents one of the most important preservation methods in terms ofthe calorific proportion of food consumed


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In the food sector, there are three primary forms of fermentation:

  1. The bacterial fermentation of carbohydrates, which happens during the production of yoghurt.
  1. Ethanol fermentation to acetic acid by bacteria (as in vinegar production).
  1. Carbohydrate fermentation by yeast to produce ethanol (as in beers, wines and spirits).

HIGH TEMPERATURES

HIGH TEMPERATURES
Heat can reduce, inhibit, or even completely stop the activity of microorganisms and enzymes because they are both heat sensitive. The type offood, related enzymes, number and type of microorganisms, storage conditions, and other preservation measures utillzed will all affect how much heat processing is necessary to create a product with an acceptable level or stadility.

  1. Pasteurisation
    This heating procedure, which normally takes place below 105°C, tries to ensure commercial sterility by utilizing "extra" elements that help to preserve the food. Depending on the type of food, the types and numbers of microorganisms present, and the actual degree of heat process required for an effective pasteurization.
  1. Batch thermal processing canning is a term still widely used in the food industry to describe a range of thermal process where the food is heated within its package to
    achieve a commercially sterile food

  1. continous thermal processing (aseptic and hot fill) UHT (ultra-high temperature or ultra-heat treatment) is a phrase used to describe in-line continuous thermal processing for food preservation. in the aseptic filing procedure, UHT treatment is done first, and then the product is filled into sterile packaging in a sterile setting.
    The form, fill, and seal (FFS) technique, which is used for sachets, trays, and pots, is an example of an aseptic package. In this process, the packing material is delivered on a reel and is formed into the package as part of the filling operation.
  1. Blanching is a method for neutralizing enzymes that is typically used right before another thermal preservation method, such as one that uses high temperatures (such as thermal processing) or lov Temperatures (e.g., freezing). Although it is not intended to do so, blanching will nonetheless result in a reduction in the number of organisms that are less heat-resistant, such as yeasts, molds, and
    some bacteria (such as Listeria, Salmonella, and E. coll)