Pasteurizers are thermal processing machines used to extend the shelf life of food products by eliminating harmful microorganisms present in their content. Named after the famous French scientist Louis Pasteur, who developed this method, pasteurizers ensure the safe consumption of many liquid foods such as milk, cream, fruit juice, beer, wine, ketchup, sauces, pickles, yogurt, rose water, and similar products. With the increase in food safety and quality standards today, pasteurizers have become essential equipment in both small-scale businesses and large industrial facilities.
The primary purpose of the pasteurization process is to neutralize pathogenic microorganisms (disease-causing bacteria) present in foods. This process is typically applied at temperatures ranging from 60°C to 100°C for a specific duration. This way, harmful microorganisms and enzymes that cause spoilage in the food structure are eliminated. However, the most important advantage of pasteurization is that it preserves the nutritional value of the food without loss. Since excessively high temperatures are not used as in sterilization, the taste, color, and nutritional properties of pasteurized products are largely preserved.
A pasteurizer relies on a systematic heat transfer process. In this process, the product is first heated, then held at a specific temperature (holding time), and finally rapidly cooled. The energy used during this process chain is recovered in modern pasteurizers through the regeneration principle. Thus, while heating the incoming raw product, the system simultaneously cools the processed hot product. This significantly reduces energy consumption and lowers production costs.
The capacity of pasteurizers varies according to the application area. In industrial production lines, these machines are typically produced with capacities ranging from 1 ton to 50 tons per hour. The MIT brand not only manufactures plate-type pasteurizers but also produces pasteurizer systems equipped with tubular heat exchangers. This provides the most suitable thermal processing solution for foods with different viscosities, fluid properties, and process requirements. Tubular exchangers are ideal for fruit purees, thick sauces, ketchup, tomato paste, and liquids with high particle content; their high-temperature resistance and resistance to clogging ensure process continuity.
The use of pasteurizers is not limited to milk and dairy products. Today, this technology is also effectively used in fruit juice, beer, wine, vinegar, herbal extracts, liquid eggs, sauces, and various herbal beverages. Additionally, it is preferred for reducing microbial load during the processing of vegetable oils or liquid food raw materials.
One of the greatest advantages provided by pasteurizers is the ability to store products for longer periods under cold chain conditions. Pasteurized foods can be delivered to consumers without spoilage for weeks or even months when stored between 5–7°C. This provides significant logistical flexibility to the producer.
In conclusion, pasteurizers are not just machines in modern food production but are the cornerstone of food safety and quality management. MIT brand's industrial pasteurizer systems stand out in the industry with their high efficiency, energy savings, fully automatic control systems, and stainless hygienic design features. For businesses aiming for sustainable production in the food industry, the right choice of pasteurizer is a strategic decision that directly affects both product quality and operational efficiency.
In the food sector, pasteurization is an indispensable process in terms of product safety, quality control, and shelf life extension. In today's production standards, every food reaching the consumer must be processed in a way that is microbiologically safe and preserves its nutritional value. This necessity has placed the pasteurization process at the center of the industry, especially when it comes to liquid foods.
The fundamental importance of pasteurization is the elimination of pathogenic microorganisms (such as Salmonella, Listeria, E. coli) present in products. These harmful microorganisms can rapidly multiply under suitable heat and humidity conditions and pose serious risks to human health. Thanks to pasteurization, these microorganisms are neutralized, making the product suitable for public health and meeting legal quality standards.
Another critical importance of pasteurization in modern food production is that it increases product durability. Foods like milk, fruit juice, sauces, and beverages, which naturally spoil quickly, can retain their freshness for weeks or even months thanks to the pasteurization process. This provides a significant advantage, especially for companies that export or have a wide distribution network.
The ability to store the product without spoilage and transport it over long distances reduces operating costs while increasing sales potential.
Another important benefit provided by pasteurization is the preservation of nutritional value. Since the product is not exposed to as high temperatures as in sterilization during this process, it largely retains its vitamin, mineral, and protein values. For example, short-term heating applied at temperatures between 63–72°C in milk pasteurization destroys harmful bacteria while preserving the natural structure and taste of the milk. Thus, products that are both healthy and have a natural taste are obtained.
In the food sector, pasteurization is also a factor that directly affects brand reliability. Consumers perceive the term "pasteurized" as an indicator of quality, especially in products like milk, yogurt, fruit juice, or beer. Therefore, it is crucial for businesses to ensure that the pasteurizer systems they use in their production lines comply with international food safety standards (such as HACCP, ISO 22000). Production in accordance with these standards provides a competitive advantage not only in local but also in global markets.
Pasteurization is also important in terms of energy efficiency and sustainable production. Today, advanced plate pasteurizers recover a large portion of thermal energy through regeneration technology. This reduces both energy consumption and the carbon footprint during production. For companies adopting an environmentally conscious production approach, this situation offers significant gains both economically and environmentally. In conclusion, pasteurization is not just a heating process but the cornerstone of quality, safety, and sustainability in the food industry. MIT brand's high-efficiency plate pasteurizer systems combine all stages of this process with automatic control, energy savings, and hygienic production principles. Thus, safe, tasty, and long-lasting products are obtained for both producers and consumers.
How Does the Pasteurization Process Occur?
The pasteurization process is based on heating the food to a certain temperature to eliminate or neutralize harmful microorganisms in its content, holding it at this temperature for a specific duration, and then rapidly cooling it. This process ensures the microbiological safety of the product while also helping to preserve its nutritional value. In modern pasteurizer systems, this process is continuously monitored and optimized with automatic control systems.
The pasteurization process generally consists of three main stages:
heating, holding at temperature (holding time), and cooling.
However, on an industrial scale, these processes occur in a much more complex heat transfer system.
1. Heating Stage
The first step of pasteurization is the controlled heating of the product. The product is first collected in a feed tank called a balance tank. This tank sends a homogeneous amount of product to the pasteurizer to ensure continuous flow. Then, with the help of pumps, the product is passed through a heat exchanger called the regeneration section. Here, the product comes into indirect contact with the previously pasteurized hot product in the system through a plate heat exchanger. This provides energy savings and raises the temperature of the raw product during the preheating stage.
The product exiting the regeneration stage has now reached a certain temperature (usually 55–65°C). From this point, the product is sent to the heating section. In this section, the product is brought to the target pasteurization temperature through heat transfer via an intermediate heat exchanger without direct contact with hot water or steam. Depending on the type of food, this temperature can vary from 63°C to 95°C. For example, milk is usually held at 72°C for 15 seconds, while fruit juice is subjected to short-term thermal processing at 90–95°C.
2. Holding at Temperature (Holding Time)
The most critical part of pasteurization is the holding tube (heat holding pipe system) stage, where the product is held at a specific temperature for a specific duration. The aim at this stage is to ensure that the entire product reaches the same temperature and that harmful microorganisms are completely eliminated.
The holding tube is usually made of long, zigzag-shaped pipes made of stainless steel. The length of these pipes and the flow rate determine the time the product stays in the system. For example, if a pasteurization time of 15 seconds is desired, the flow rate is automatically adjusted accordingly.
At the end of the system, there is a temperature sensor and a control valve. If the product's temperature has not reached the desired value, the valve automatically activates and redirects the product back to the beginning of the system. This closed-loop system guarantees that the product is fully pasteurized.
3. Cooling Stage
After the product is held at the pasteurization temperature for the required time, it passes to the regeneration and cooling sections of the system. First, in the regeneration section, it exchanges heat with the incoming raw product, reducing its temperature slightly. Then, in the cooling section, it is cooled to 4–7°C with the help of ice water or cooling fluid.
This rapid cooling process extends the product's shelf life and prevents microbial regrowth. The cooled product is then directed to filling lines or storage tanks.
4. Process Control and Automation
In modern industrial facilities, the pasteurization process is entirely managed by automatic control systems. All process parameters are monitored in real-time through temperature sensors, flow meters, and pressure indicators. PLC or SCADA systems optimize temperature and flow rate at every stage. This ensures that product quality remains consistent in every batch and minimizes human error.
5. Energy Recovery and Efficiency
The most energy-consuming part of the pasteurization process is the heating stage. However, thanks to regenerative heat exchangers, the hot product in the system preheats the incoming cold product. This reduces the total energy requirement by 60–70%. Thus, environmentally friendly production is achieved, and operating costs are significantly reduced.
6. Quality and Safety
A correctly applied pasteurization process preserves the physical, chemical, and sensory properties of the product. Incorrect temperature or time settings can lead to deterioration in the product's taste, darkening in color, or nutrient loss. Therefore, the stainless plates, hygienic seals, and automatic control valves used in the system are the most critical components that guarantee food safety.
Pasteurization Temperatures and Application Areas
Pasteurization temperatures are determined based on the type of food to be processed, the resistance of the microorganisms it contains, and the desired shelf life. The structure of the food, pH value, fat content, protein amount, and enzyme density directly affect the temperature and duration to be applied. Therefore, specific pasteurization parameters are determined for each product.
In general, the pasteurization process is applied using two main methods:
• Low Temperature Long Time (LTLT) • High Temperature Short Time (HTST)
Low Temperature Long Time Pasteurization (LTLT)
This method is generally preferred for delicate foods or small-scale production. The product is held at approximately 63°C for about 30 minutes. This was the most commonly used method in the early days of milk pasteurization.
The advantage is that it causes minimal damage to the chemical structure of the product; the disadvantage is that the process takes a long time and energy consumption is higher.
Foods pasteurized using the LTLT method:
• Fresh milk
• Yogurt production milk
• Fruit purees
• Plant-based drinks (such as almond milk or oat milk)
High Temperature Short Time Pasteurization (HTST)
This is the most commonly used method in modern industry. In this method, the product is held between 72°C and 75°C for 15–20 seconds. Thanks to the short duration, microorganisms are neutralized, and the nutritional value of the product is preserved.
The HTST method is applied especially in large-capacity production lines with plate heat exchangers.
Foods pasteurized using the HTST method:
• Drinking milk
• Fruit juice and nectars
• Wine and beer
• Liquid egg
• Ketchup, mayonnaise, sauces
• Rose water and aromatic extracts
Very High Temperature Short Time Pasteurization (Pre-UHT)
In some foods, pasteurization is applied at higher temperatures like 90–95°C for very short durations. This method is especially preferred for high-viscosity or enzyme-rich products.
For example, tomato juice is pasteurized at 94°C, pickle juice at 82°C, and fruit sauces around 90°C.
These temperature ranges allow for the breakdown of enzymes in the product, preventing unwanted changes in taste, color, or consistency.
The Scientific Basis of Pasteurization Temperatures
The effectiveness of pasteurization is calculated based on the death curves and heat resistance coefficients of microorganisms. Each microorganism has a different time required to die at a specific temperature. For example:
• Coxiella burnetii bacteria (one of the most resistant bacteria in milk) is neutralized at 72°C in 15 seconds. • Bacteria like E. coli and Salmonella are quickly eliminated at 60–65°C.
• Listeria monocytogenes bacteria die at temperatures above 70°C.
Therefore, food engineers determine the optimal temperature-time combinations based on the type and content of the product. The goal is to eliminate bacteria while preserving nutritional value.
Application Areas of Pasteurization
The pasteurization process is not limited to dairy products. Today, this method is used in many branches of the food industry:
• Beverage industry: Fruit juice, beer, wine, herbal drinks
• Dairy industry: Milk, yogurt, cream, whey
• Sauce and food additive production: Ketchup, mayonnaise, tomato paste, fruit sauces
• Herbal extracts and flavors: Rose water, lemon juice, plant extracts
• Egg and derivative products: Liquid egg, egg mixtures
Factors Affecting Quality
The effectiveness of pasteurization depends not only on temperature but also on factors such as duration, pH, viscosity, and the fat content of the product. For example, in low-acid (pH>4.5) products, bacteria have high resistance, so higher temperatures may be required. In contrast, lower temperatures are sufficient for acidic products like fruit juice.
Pasteurization Process in Milk, Fruit Juice, and Other Products
The pasteurization process varies according to the temperature and duration parameters applied to different types of food. This is because the chemical structure, microbiological load, and targeted shelf life of each product are different. Although the purpose of pasteurization in foods like milk, fruit juice, beer, wine, or sauces is the same — to ensure product safety by eliminating microorganisms — the methods and equipment used differ from each other.
Milk Pasteurization
Milk is the most commonly pasteurized food. Raw milk is not suitable for direct consumption as it contains many different types of bacteria and enzymes. Therefore, milk is heated to specific temperatures to remove pathogenic bacteria.
Modern milk pasteurizers typically operate using the HTST (High Temperature Short Time) method. In this method, milk is held at 72°C for 15 seconds and then rapidly cooled to 4–5°C. As a result of this process:
• Harmful microorganisms in the milk are completely eliminated,
• Protein, calcium, and vitamin values are preserved,
• The natural taste of milk is not altered,
• The product gains durability for 5–7 days under refrigerator conditions.
Some producers may prefer different temperature values for special milk products (e.g., milk for yogurt or cheese production). In yogurt production, milk is usually heated to 85–90°C and held for a short time; this process not only eliminates harmful bacteria but also ensures the denaturation of proteins affecting the consistency of the milk.
Fruit Juice Pasteurization
Fruit juices are relatively resistant to bacteria due to their acidic nature; however, pasteurization is also mandatory for these products due to enzymatic spoilage and yeast formation. In fruit juice pasteurization, a process of 90–95°C for 15–30 seconds is generally applied.
This temperature range helps preserve the natural color, aroma, and vitamins of the fruit while extending the product's shelf life to several months.
In fruit juice pasteurization, plate heat exchangers are used to ensure the product progresses with turbulent flow instead of laminar flow. This maximizes heat transfer and ensures the product heats evenly.
In fruit nectars, purees, or beverages containing pulp, heat transfer is more challenging due to high viscosity. In this case, tube-type or tubular pasteurizer systems are preferred. MIT brand tubular pasteurizers effectively ensure heat transfer even in high-viscosity products, preventing quality loss.
Beer and Wine Pasteurization
The pasteurization of alcoholic beverages is important not only for microbial control but also for preserving the chemical balance of the product.
Beer pasteurization is usually carried out with a low-temperature process lasting 20–30 minutes at 60°C. This temperature neutralizes the yeast and bacteria in the beer while preserving the foam structure and aroma of the beverage.
In wine, pasteurization is applied at a lower temperature; the preferred method is usually holding at 60–65°C for 20–30 minutes. This is because high temperatures can disrupt the color and tannin balance of the wine.
The purpose of pasteurization in these types of products is not sterilization; it is to ensure microbial stability and prevent secondary fermentation that may occur in the bottle. Therefore, beer and wine pasteurizers are usually tunnel-type systems; the product is heated and cooled for a specific duration after bottling to complete the process.
Sauces, Ketchup, and Mayonnaise
In high-viscosity foods, especially products like sauces, ketchup, and mayonnaise, the purpose of pasteurization is to ensure both microbial safety and preserve the physical consistency of the product.
In these products, the temperature is generally maintained in the range of 85–90°C. However, it is crucial that heat distribution is homogeneous during this process. Because if some areas of the viscous mixture do not heat sufficiently, bacteria may survive.
The special mixing systems and high-temperature-resistant seals used in MIT pasteurizers ensure complete pasteurization even in such products. Additionally, with double-walled pipe systems, the product heats evenly without the risk of burning.
Herbal Extracts and Rose Water
In products with herbal content, such as rose water or lemon extract, temperature control during pasteurization is extremely important.
In these types of products, the process usually lasts around 15–20 seconds at 80–85°C. This temperature ensures the preservation of aromatic components without degradation.
Excessive thermal processing can cause the rose water to lose its fragrance or become cloudy, so temperature is continuously monitored with sensitive sensors at this stage.
Energy Efficiency and Quality Preservation
The common point in all these product groups is the balance between energy efficiency and quality. During pasteurization, the heated product transfers its energy to the incoming raw product while cooling in the regeneration section. Thanks to this energy recovery, the system's total energy requirement is reduced by 60–70%.
Additionally, since temperature and flow rate are kept constant with automatic control systems, the same quality standards are achieved in every production batch.
Although different temperature and duration combinations are applied for each type of food, the basic principle is the same: to ensure the microbiological safety of the product and preserve its nutritional value.
MIT pasteurizer systems manage all these processes with automatic temperature control, energy recovery, and hygienic design principles. Thus, high quality and reliability are always achieved in different products such as milk, fruit juice, sauces, beer, or herbal extracts.
Conclusion
Pasteurization is one of the cornerstones of modern food industry in terms of food safety and quality control. Thanks to this process, milk, fruit juice, beer, wine, sauces, creams, and many other food products are purified from harmful microorganisms and safely delivered to the consumer. Pasteurization applied with the correct temperature and duration combinations preserves the nutritional value of the product and extends its shelf life.
Today, it is of great importance for producers not only to ensure microbiological safety but also to increase energy efficiency and achieve sustainable production goals. At this point, MIT brand's industrial pasteurizer systems stand out with their high-efficiency heat transfer technologies.
MIT pasteurizers reduce operating costs by providing energy recovery with the regeneration principle, and offer the same quality standard in every production batch thanks to automatic temperature control systems. Its stainless steel structure and hygienic design create a production environment fully compliant with food safety standards.
Additionally, MIT pasteurizer systems are not only used in the milk and beverage industry; they also have a flexible structure that can be used in fruit processing, sauce production, herbal extracts, aromatic liquids, cosmetic liquids, and the pharmaceutical industry. This versatility provides companies with both product diversity and production flexibility.
In conclusion, pasteurization is not just a heating process; it is the engineering foundation of quality, safe, and sustainable production.
With MIT pasteurizer solutions, businesses maximize product safety and adopt an environmentally friendly production approach for the future by efficiently using energy resources.