Introduction
Microwave Assisted Pasteurization and Sterilization (MAPS) System is an innovative food processing technology that uses microwave energy to rapidly and uniformly heat packaged foods. It is also called Microwave Assisted Pasteurization and Sterilization System. This technology eliminates harmful bacteria, viruses, and other pathogens that can cause foodborne illnesses. At the same time, it also preserves the food’s taste, texture, and nutritional value.
Diving Into Microwave-Assisted Pasteurization and Sterilization System (MAPS)
A Microwave-Assisted Pasteurization and Sterilization System (MAPS) uses microwave radiation to heat food packages uniformly. It allows for rapid and efficient pasteurization or sterilization by directly generating heat within the food itself. The process of MAPS follows a water bath which ensures even heat distribution to prevent “hot spots”. It also ensures minimal damage to the food’s quality as compared to traditional heating methods. The process utilizes a 915 MHz microwave frequency for better penetration into the food package It is often used for ready-to-eat meals or other sensitive food products.
Process Followed by MAPS
Microwave heating reduces heating time and improves heating uniformity when compared with conventional hot water and steam heating. The microwaves penetrate the food and generate heat throughout the whole volume of food. It reduces the temperature gradient during heating. The system uses microwaves at a specific frequency (typically 915 MHz).
MAPS consists of four sections:
- Preheating
- Microwave Heating,
- Holding, and
- Cooling
Water Circulation System
Each section of MAPS has a separate water circulation system to control the water temperature and flow rate. The circulating water ensures uniform temperature distribution in food products. Its temperature is set at 70 to 90 °C following the desired shelf-life of the processed products. The water Circulation system also helps in cooling the food items in the cooling stage.
Microwave Section: Pre-Heating and Heating Stage
The microwave section of MAPS has four single-mode cavities. These are connected to microwave generators. The first two cavities operate on a power of approximately 5 kW. Further, the other two cavities equally split 8.7 kW.19 Polymeric trays or pouches. These sections contain food and are placed in transport carriers and heated in the preheating section to about 50 °C. These trays are further moved through the microwave heating section where they are heated simultaneously with microwave energy and hot circulating water before moving to the holding section.
Holding Stage: Treating With Pasteurization Temperature
The speed of the belt in the microwave heating section and the holding time of the food package are adjusted to achieve the desired pasteurization. It takes 2.5–4 min for microwave heating. It largely depends on package thickness and the time taken by the cold spots of food packages to reach the desired pasteurization temperature for the thermal inactivation of target bacterial and viral pathogens.
Cooling Stage
The MAPS system uses circulating cold water for cooling the food items. The system circulates water in closed loops to cool all the sections. It also helps in zero water loss in the operation.
Advantages of MAPS System
Pathogen Elimination
MAPS system destroys harmful microorganisms and makes the food safe for consumption. It enhances food safety and helps in limiting food-borne diseases.
Enhancing Food Quality
The process of rapid and uniform heating followed in MAPS helps to preserve the food’s natural flavors, textures, and nutrients, resulting in higher-quality products.
Increasing Shelf Life
MAPS System is equally helpful in increasing the shelf life of food products by reducing microbial activity.
Reduced Processing Time
It reduces the time required for pasteurization and sterilization as compared to traditional methods.
Chemical Free Preservation
MAPS system reduces the need for chemical preservatives in food preservation and thus contributes to building a sustainable food industry.
Limitations of Microwave Assisted Pasteurization and Sterilization System (MAPS)
Dependent on Dielectric Properties
Microwave heating largely depends on the dielectric properties of the food materials, which can vary between different food types. It leads to uneven heating and potential issues with pasteurization efficiency.
Cavity Size
MAPS system carries limitations in terms of food batch size. This is because microwaves may not heat large batches of food materials due to the limitations of the microwave cavity size. It impacts processing capacity.
Packaging Materials
MAPS System also has limitations in terms of packaging materials. Some of these materials can absorb microwaves which affects the heating patterns and potentially requires special packaging designed for microwave use.
Nutrient Degradation
MAPS System is less damaging in terms of nutrient degradation than conventional heating methods. However, excessive microwave heating may lead to some nutrient loss in certain foods.
Challenges in Monitoring
The MAPS System encounters a challenge in terms of precise temperature monitoring throughout the food product. Microwave pasteurization becomes difficult due to the rapid heating process as it requires specialized monitoring systems.
Conclusion: The Need for Innovation Like MAPS
According to the World Health Organization (WHO), an estimated 600 million people fall ill and 420,000 people die from unsafe food. It results in the loss of 33 million healthy life years (DALYs). Further, children under 5 years of age are at particularly high risk. An estimated 125,000 children die from foodborne diseases every year. These illnesses and deaths are largely preventable by the inclusion of state-of-the-art technologies in food processing. MAPS System is such a technology that can help to eliminate food-borne illnesses and preserve food items. The food processing industry must focus on the limitations of the MAPS System to make it more effective for food safety.