Cooling, chilling and cold stabilization with emerging technologies process intensification
Cooling is used to reduce the temperature of the food from one processing temperature to another or to a required storage temperature. Chilling is a processing technique in which the temperature of a food is reduced and kept in a temperature between -1 to 8°C. The objective of cooling and chilling is to reduce the rate of biochemical and microbiological changes in foods, to extend the shelf-life of fresh and processed food, or to maintain a certain temperature in a food process, e.g. in fermentation and treatment of beer. Cooling is also used to promote a change of state or aggregation, e.g. crystallization. The objective of cold stabilization is to precipitate our tartrates in wines, or fatty acids in spirits before bottling. Cooling, chilling and cold stabilization are widely used in the food industry sector. Chilling is used for preservation of a lot of perishable foods. In the wine sector, cooling and chilling are applied to clarify the must before fermentation. Cold stabilization is used in the beer, wine and spirit sectors. Beer is cold stabilized to precipitate the protein-polyphenol adduct. The beer is kept between -2 to -3°C for at least 12 hours.
(European Commission, 2006)
Further Information: Cooling, chilling and cold stabilization in food industry
Description of technology, techniques and methods
High Pressure Processing (HPP)
The Ice Crystals formation damage mechanically cell structure in tissue derived food products, puncturing cell wall and inducing denaturalization of proteins. HPP technology Takes advantage of the non-frozen region of water below 0°C at elevated pressures, avoiding adverse freezing effects (-22°C with 207.5 MPa).
(Tao, Sun, Hogan & Kelly, 2014)
Further Information: HPP
- The mechanical and biochemical stress caused by the ice leads to irreversible tissue damage. The application of electric and magnetic effects has been identified as a possible means to reduce the size of ice crystals during freezing of biological tissues.
- The technology enables a reduction on the size of the crystals (60%) leading to a better conservation quality of the food.
(Xanthakis, Le-Bail, Ramaswamy, 2014)
Further Information: microwaves
The effect of the ultrasonic technology in the freezing process is related with the pre-existing bubbles in liquids that affect ice nucleation and crystallization. Liquids containing pre-existing bubbles nucleate with a shorter delay. Adding bubbles to liquid samples could be a promising and feasible approach to improve the effectiveness of ultrasound irradiation with great potential for the frozen food industry.
(Hu et al, 2013)
Further Information: ultrasound
Changes in the process
Energy saving potentials
Ultrasound technology may enable energy savings due to the accelerated processing. Most of the technologies are focused on quality improvement and this can increase the energy consumption in the process.
Changes in the energy distribution system
Higher electricity demand compared with thermal energy demand.
- European Commission (2006) Best Available Techniques (BAT) in the Food, Drink and Milk Industries. Reference Document: Best Available Techniques [Online]. Available at: http://eippcb.jrc.ec.europa.eu/reference/BREF/fdm_bref_0806.pdf (Accessed: 20th February 2015).
- Hu, F., Sun, D., Gao, W., Zhang, Z., Zeng, X., Han, Z. (2013) 'Effects of pre-existing bubbles on ice nucleation and crystallization during ultrasound-assisted freezing of water and sucrose solution', Innovative Food Science & Emerging Technologies, 20(October), pp. 161-166.
- 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.
- Xanthakis, A., Le-Bail, A., Ramaswamy, H. (2014) 'Development of an innovative microwave assisted food freezing process ', Innovative Food Science & Emerging Technologies, 26(December), pp. 176-181.