Saturday, March 20, 2010

Pasteurization: Advantages and Disadvantages

When God Created the world, He also included Microorganisms to make our life more complicated and more frustrated. anyway, Life without microorganism is hard. We can't have Vinegar, cheese, cinnamon Beer, Wine and etc. more microorganism are use in food processing such as fermentation. BUT not all microorganisms are helpful there are some who are intended to cause health problems such as Viruses, Molds, Yeast, and Bacteria. Bacteria species has the most number of harmful microorganisms. Mostly can cause death such as Escherichia coli, Staphylococcus aureus, Clostridium spp. and many more. So that's why, people invented the process of sterilization.

Centuries Ago, people are finding the right key on what causes food spoilage and food poisonings. This query last until 1860 when a man named Louis Pasteur had discovered and proved that microorganisms are the one causes Food spoilage and more. He is remembered for his remarkable breakthroughs in the causes and preventions of disease. His discoveries reduced mortality from puerperal fever, and he created the first vaccine for rabies. His experiments supported the germ theory of disease. He was best known to the general public for inventing a method to stop milk and wine from causing sickness, a process that came to be called pasteurization. He is regarded as one of the three main founders of microbiology, together with Ferdinand Cohn and Robert Koch. Pasteur also made many discoveries in the field of chemistry, most notably the molecular basis for theasymmetry of certain crystals. His body lies beneath the Institute Pasteur in Paris in a spectacular vault covered in depictions of his accomplishments in Byzantine mosaics.

Other Scientist follow and rely on his principle and they found that Pasteurization can be applied also in many food.

Food that can applied with Pasteurization

§ Almonds

§ Apple cider

§ Beer

§ Canned food


§ Cornbread

§ Crabs

§ Cream

§ Eggs

§ Fruit juice

§ Honey (not necessary unless it is diluted)

§ Juice

§ Maple Syrup

§ Milk

§ Palm wine

§ Ready Meal

§ Soy sauce

§ Sports drinks

§ Tobacco

§ Vinegar

§ Water

§ Wine

Pasteurization is a heat treatment that kills part but not all of microorganisms present and usually involves the application of temperatures below 100 oC. The neating may be by means of steam, hot water, dry heat, or electric currents, and the products are cooled promptly after the heat treatment (Frazier and Westhoff, 1988).

Pasteurization relies on the principle that most harmful bacterial can be killed by heat. The most effective way to kill bacteria is boiling, but this compromises the flavor of the liquid.Pasteurization strikes a happy medium, keeping the flavor delicious while making the food safer. In addition to minimizing the risk of sickness, pasteurization also makes foods more shelf stable and less likely to rot, meaning that fresh dairy products and juices are available to more people (Frazier and Westhoff, 1988).

According to Frazier and Westhoff (1988), There are two primary methods of pasteurization: the liquid can be heated to 145 degrees Fahrenheit (63 degrees Celsius) or Low-Temperature-Long-Time (LTLT) and held there for at least thirty minutes, or the liquid can be flash pasteurized at 161 degrees Fahrenheit (72 degrees Celsius) or High-Temperature-Short-Time (HTST) for a minimum of 16 seconds.Pasteurization can be done using a continuous method, where the liquid flows through a pasteurization system, or by using a batch method, where one batch of the liquid is pasteurized at a time. Continuous pasteurization is popular for large producers, because it does not slow the supply line as much as batch pasteurization does.

Pasteurization must be performed on clean equipment. If bacteria is introduced after the liquid has been pasteurized, it can colonize it and potentially cause an outbreak of food borne illness. For this reason, companies which perform pasteurization are subject to frequent inspections to ensure that the equipment they are using is safe, and that the liquids they are pasteurizing are being handled correctly(Frazier and Westhoff, 1988).

After pasteurization, bacteria can still appear. It is important that foods be safely handled and stored at every step of the supply process from animal, fruit or vegetable to stomach. In most cases, after food is pasteurized it should be refrigerated. The food is held in refrigeration until it is shipped out in cooled trucks to grocery stores, which store the food under refrigeration until consumers purchase it. Home consumers are responsible for following directives regarding temperature to ensure that the foods they are consuming are safe (Frazier and Westhoff, 1988).

Uses of Pasteurization according to Frazier and Westhoff (1988):

  • Ø When more rigorous heat treatments might harm the quality of the product, as with market milk.
  • Ø When one aimis to kill pathogens.
  • Ø When the main spoilage organisms are not very heat resistant.
  • Ø When any surviving spoilage organisms will be taken care of by additional preservative methods to be employed.
  • Ø When competing organism are to be killed, allowing desired fermentation, usually by added starter organisms.

Advantages of Pasteurization according to Frazier and Westhoff (1988):

Ø It does not produce an unpleasant cooked flavour.

Ø Shelf life of milk is increased due to a marked decrease in the total bacterial count.

Ø Some Harmful pathogens especially TB bacteria are destroyed.

Ø It inactivates enzymes such as phosphatase and lipase in milk which adversely affect the quality of milk.

Ø It increases shelf-life of a product such as Milk and other dairy products.

Ø Save time.

Disadvatages of Pasteurization according to Frazier and Westhoff (1988):

  • Ø Strict monitoring must be observed.
  • Ø Cannot be applied to other products.


Frazier, W.C. Westhoff, D.C. (1988). Food Microbiology, 3rd edition. McGraw-Hill Publishing. New York, USA. Pp. 111 - 112

1 comment:

  1. sorry 2 ask..but this fact true or false??
    cause i want 2 complet my assingment..