Using a combination of heat and cold, pasteurization effectively reduces the number of harmful bacteria that can cause food spoilage while preserving its flavor, texture, and nutritional value.
Pasteurization is a process that has revolutionized the food industry and has been a critical factor in preserving food and improving its quality. Developed by the scientist Louis Pasteur in the late 19th century, pasteurization is a process of heating food to a specific temperature for a certain amount of time in order to kill off any harmful bacteria and extend its shelf life.
This process has become an integral part of the food industry, providing consumers with safe and nutritious food products that will last longer and taste better. Pasteurization is a simple yet effective way to ensure that food remains safe and enjoyable to consume.
Benefits of Pasteurization Food Preservation
There are many benefits to the pasteurization process and food products that have undergone pasteurization.
These include reduced spoilage, a greater variety of food selection, reduced foodborne illnesses, and better taste and texture. Spoilage is one of the biggest concerns with food safety, as unprocessed food items can quickly become contaminated and cause disease.
As mentioned, a greater variety of food selection is one of the key benefits of pasteurization. While many foods, such as milk, were previously only available in a few select varieties, pasteurization has allowed them to be safely produced and distributed in much larger quantities.
This has allowed various food products to be made and distributed, making it easier for people to find the foods that work best for their dietary needs and preferences.
Reduction in foodborne illnesses is another significant benefit of pasteurization food preservation. While the exact number of diseases prevented by food pasteurization is challenging to calculate, it is estimated that foodborne illnesses can cause 128,000 hospitalizations and 3,000 deaths each year in the United States alone.
Pasteurization is a critical process that helps to reduce these numbers by eliminating harmful bacteria in food products.
Better taste and texture of food are another advantage of pasteurization. While the process does not actually change the flavor or texture of food, it does help extend certain products’ shelf life.
This allows certain foods to be preserved for a more extended period, which can help maintain their texture and flavor for a more extended time.
What Are The 3 Types Of Pasteurization Food Preservation?
There are three primary ways of pasteurization: low-temperature long time (LTLT), high-temperature short time (HTST), and ultra-high temperature (UHT).
- LTLT typically uses temperatures of 145 to 149°F for a period of 30 minutes or 167°F for 8 to 10 minutes. The minimal heat treatment for market milk is 145.4°F for 30 minutes, while grape juice is 171°F for 30 minutes.
- Meanwhile, HTST requires temperatures of around 185° to 194°F or higher and a time of seconds. Milk pasteurization through this method involves a temperature of 161°F for 15 seconds, while grape wines are usually pasteurized for one minute at 178 to 185°F.
- The ultra-high temperature (UHT) approach is a process referred to as quick, high, or flash pasteurization that uses temperatures ranging from 185-194°F or higher and is applied for a span of a few seconds. The most common temperature/time pairings are 190.4°F for 1 minute, 212°F for 12 seconds, and 250°F for 2 seconds. This technique results in a commercially sterile product since it eliminates all but the most resilient spores.
No matter the temperature/time combination, the destruction of bacteria is very close to the same; however, the 250°F for 2 seconds treatment produces the best quality product when it comes to flavor and vitamin preservation.
The downside to this brief holding time is the need for special equipment, which is more intricate and costlier than long-term low-temperature/high-temperature equipment.
Process of Pasteurization
As mentioned before, heat treatment, known as pasteurization, is applied to food for a short period to reduce the number of microorganisms, especially those that can harm humans.
This process is especially useful when the food cannot handle a high temperature or freezing, and the microorganisms it contains are not very tolerant of heat.
Pasteurizing low-acid foods aims to destroy microorganisms that cause illness, while acid foods aim to eliminate the microorganisms that cause spoilage and inactivate the enzymes.
For instance, milk is pasteurized at 145.4°F for 30 minutes or 160.7°F for 15 seconds to kill the microbes Brucella abortus, Mycobacterium tuberculosis, and Coxiella burnetii.
Beer needs to be heated to 149°F-154.4°F for 20 minutes in the bottle to destroy lactic acid bacteria and yeasts, while fruit juices should be pasteurized at 149°F for 30 minutes, 170.6°F for one minute or 190.4°F for 15 seconds to target yeasts, fungi, pectinesterase, and polygalacturonase.
Besides annihilating a few bacteria, pasteurization also deactivates some enzymes. However, this process has a small effect on the color and taste.
Can Other Methods Be Applied Along With Pasteurization Food Preservation?
As pasteurization does not eradicate every microbe, it is usually incorporated with another means of sustaining freshness, such as refrigeration.
Standard preservation techniques used in combination with pasteurization comprise cooling as with milk; chemicals- pickles, fruit juices; fermentation (additives)- sauerkraut, cheeses; and packaging (no air conditions)- beers, fruit juices.
As mentioned above, the temperatures at that particular foods need to be pasteurized vary according to the type of food.
The primary method of pasteurization is by heating food in a controlled environment. This pasteurization method is often referred to as “batch” pasteurization, where a large amount of food is heated in a single batch.
The batch pasteurization method is most commonly used for milk, juices, and bottled water.
A less common pasteurization method is a continuous flow pasteurization method, which is also used for items such as dairy products.
This method uses a system that consists of a rotary valve, a heat exchanger, a pump, and a steam flow meter. The continuous flow pasteurization method is also used for various other foods, including juices, bottled waters, syrups, and many dairy products.
Pasteurization and Nutritional Value
The majority of studies that have compared the nutritional value of foods that have been pasteurized to unprocessed foods have found that pasteurization does not introduce a significant negative effect on the nutritional value of the food product.
The pasteurization process may reduce the amount of specific vitamins in foods. For instance, pasteurization may slightly decrease the vitamin C in orange juice. However, orange juice already contains enough to meet the suggested daily allowance, as stated by the American Council on Science and Health.
On the other hand, pasteurization has no considerable impact on the nutrient content in milk, according to the United States Food and Drug Administration.
Although heat treatment is the primary factor that influences the time period of the shelf-life, pasteurization and ultrahigh temperature processes still have an effect on the composition of the milk, resulting in a reduction of total fat and total solids and an increase of urea.
Usually, unprocessed milk stored in a hot environment can last between two to three hours to a maximum of twenty-four hours. On the other hand, the shelf-life of unpasteurized cheese varies from four to five days up to five years, depending on the type.
Summary of Pasteurization
Pasteurization is the process of heating food to a specific temperature for a certain amount of time in order to kill off any harmful bacteria and extend its shelf life.
This process has been widely adopted in the food industry, allowing food to be safely stored and transported while maintaining its main nutritional and sensory qualities. While pasteurization does not kill all harmful bacteria, it does help to reduce the total number of harmful bacteria in food products.
This helps to reduce the risk of foodborne illnesses by making it difficult for harmful bacteria to survive and thrive in food products. Pasteurization has many benefits, including reduced spoilage, a greater variety of food selection, reduced foodborne illnesses, and better taste and texture.
Additionally, it helps extend certain food products’ shelf life, allowing for safer storage and transportation. Pasteurization is a critical process that helps to promote food safety by helping to reduce the total number of harmful bacteria in food products.
This process has been widely adopted in the food industry, allowing for safer and more efficient production of various food products.