TABLE 3.

Preservation techniques and comparison.

Preservation technique	Description	Food products	Conditions of process	Detailed mechanism	References
Pasteurization	Utilizes controlled heating to deactivate pathogenic microorganisms and enzymes, preserving sensory and nutritional quality	Pasteurized Milk, Fruit Juices (e.g., Orange Juice), Pasteurized Beer	Typically, 60–100°C; time and temperature dependent on product acidity and water activity	Low‐level thermal process targeting pathogenic bacteria in low‐acid (pH > 4.5) and high‐acid foods (pH ≤ 4.5)	Tavman et al. (2019)
Sterilization	Applies high‐temperature heat treatment to achieve complete inactivation of all forms of microorganisms, including spores	Canned Vegetables, Canned Meat, Shelf‐Stable Low‐Acid Foods	Exceeds 100°C, often 115–130°C; specific time–temperature combinations, e.g., 121.1°C for 3 min for a 12D reduction of Clostridium botulinum	Intensive thermal processing aimed at achieving commercial sterility in low‐acid foods	Ramesh (2020)
Refrigeration	Lowers the storage temperature to inhibit microbial growth and enzymatic activity, maintaining food quality for short‐term preservation	Chilled Fresh Produce, Dairy Products (e.g., Cheese), Chilled Raw Meat	Storage temperatures typically above freezing and below 15°C	Reduction of metabolic and microbiological activity through lower temperatures without freezing	Augusto et al. (2018)
Freezing	Transforms water in food to ice, significantly slowing down microbial activity and biochemical reactions	Frozen Vegetables, Frozen Dairy Products like Ice Cream, Frozen Meat Products	General practice requires temperature reduction to around −18°C for storage	Three‐stage process: Precooling to freezing point, phase transition with latent heat removal, and tempering to final storage temperature	Tavman and Yilmaz (2017)
Ohmic heating	Employs electric current to generate heat internally within the food product, enhancing quality and reducing processing time	Liquid Egg Products, Fruit Juices (e.g., Apple Juice), Soups with Particulates	Rapid volumetric heating with variable conditions based on food composition	Electrical resistance of food causes internal heating, effective for liquid–solid mixtures and viscous fluids	Rodrigues et al. (2021)
Microwave heating	Utilizes electromagnetic waves for rapid internal heating, suited for various food processing applications	Microwaveable Ready Meals, Snacks like Popcorn, Reheatable Food products	Utilizes specific microwave frequencies (915 or 2450 MHz), achieving rapid temperature increase	Electromagnetic waves cause dipole rotation and ionic polarization in food molecules, generating internal heat	Ahmed and Ramaswamy (2007)