Sterilization in emerging technologies process intensification
Sterilization is a controlled heating process used to completely eliminate all living micro-organisms, including thermo resistant spores in milk or other food. It can be achieved by moist heat, dry heat, filtration, irradiation, or by chemical methods. Compared to pasteurization, a heat treatment of over 100°C is applied for a period long enough to lead to a stable product shelf-life. Sterilization is used to treat all types of food products. These include milk, juices, beer and many others. UHT sterilization is used for low viscosity liquid products (milk, juices, cream, wine, and salad dressings), foods with discrete particles (baby foods, tomato products, fruits and vegetables juices, soups) and larger particles (stews). (European Commission 2006)
Further Information: Sterilization in food industry
Description of technology, techniques and methods
High Pressure Processing
This application aims at inactivating spore-forming bacteria and bacterial endospores usually using high temperature for long time affecting the quality of the product. A combination of pressure and thermal processing seems to be more effective (60-90 °C till 100-130°C with the internal compression effect of about 500 MPa), a process more than 15 time faster. Material resistance and economic challenges make high temperature high pressure equipment out of the market.
(Tao, Sun, Hogan, Kelly, 2014)
Further Information: HPP
The technology enables an improved uniformity of heating for in-package sterilization. A microwave power profile optimized for the package is possible. There is a promising 915 MHz single mode sterilization for processing packaged food. The food is immersed in pressurised hot water simultaneously heated by microwaves. 5-8 min processing for safe and high quality food. Especially good for not homogeneous food.
(Ozkoc, Sumnu & Sahin 2014).
Further Information: microwaves
Ultrasound technology, assisting to other processes of sterilization, is effective minimizing the flavor lost, enabling a greater homogeneity and energy savings. The results differ depending on the type of bacteria and very high intensities are need for permanent sterilization ultrasound alone. Tested life extension of food, enhanced stability. Product quality, texture and flavours can be maintained if process times are kept to a minimum and treatment temperatures are reasonably low.
Further Information: ultrasound
Changes in the process
Energy saving potentials
Potential energy savings per unit produce when pasteurization process is accelerated. Most of the technologies applied on this operation aims to a better quality of the product or a less damaging pasteurization.
Changes in the energy distribution system
Passing from thermal energy sources to a more electrical intense energy system.
- Ozkoc S., Sumnu G., Sahin S. (2014) 'Part IV: Alternative thermal processing: Chapter 20 Recent Development in Microwave Heating', in Sun, D. (ed.)Emerging Tehcnologies for Food Processing. UK: Academic Press, pp. 361-377.
- Paniwnyk, L. (2014) 'Part III Other not Thermal Technologies: Chapter 15 Application of Ultrasound', in Sun, D. (ed.) Emerging Technologies for Food Processing. UK: Academic Press, pp. 361-377.
- Tao, Y., Sun D., Hogan E., Kelly, A. (2014) 'High pressure processing', in Sun, D. (ed.)Emerging Tehcnologies for Food Processing. UK: Academic Press, pp. 3-20.