From Food Tech Innovation Portal
Packaging material suitable for infrared heating of food
- Identification
- How does it work?
- What can it be used for?
- What can it not be used for?
- Implementation
- Related Facilities
- Further Information
Identification
| Key words | Packaging material, infrared heating, in-pack processing, surface pasteurisation |
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| Latest version | 2011/05/12 |
| Completed by | SP |
How does it work?
| Primary objective | To enable in-pack heating or pasteurisation of food surfaces | |||
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| Working principle | Infrared (IR) heating can be used for surface pasteurisation of different food products. Recontamination after IR surface pasteurisation can be reduced using in-pack treatment but there is limited knowledge regarding how different packaging materials are affected by IR. The effect on different plastic films has been evaluated and PA/PE, PP/EVOH/PP/PE, OPA/PE, OPET//PE-EVOH-PELLD (Ecobar 3), OPET//PELD-EVOH-PELLD (Ecobar 2) and PET proved to be suitable for this application in regard to the heat flux and the mechanical properties of the film (1). These plastic films have a high transmittance, low absorbance and low reflectance of the energy and they are also heat resistant. PA/PE can be shaped as a pouch around a food product. This film has been tested in contact with a piece of white bread and the reduction of water activity of the bread after IR treatment is lower than without the package environment (1). Inside a pouch the heating rate is in general high and therefore IR heated products in a pouch needs a short heating time or low IR intensities. | |||
| Images | | |||
| Additional effects | When using in-pack surface pasteurisation recontamination can be avoided. | |||
| Important process parameters | IR emission, IR power, temperature control, processing time, IR wavelength. | |||
| Important product parameters | Packaging material: High transmittance, low absorption, low reflectance, heat resistant to at least 100˚C (1). Other important properties of the materials are tensile strength and stress, elongation and barrier properties e.g. oxygen permeability and water vapour permeability (2).
Food product: Thickness of the product, moisture content, water activity, temperature of the food sample, food composition. |
What can it be used for?
| Products | Food products packed in transparent and heat resistant materials. |
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| Operations | In-pack decontamination of food surfaces by IR heating. |
| Solutions for short comings | There is a need of shelf life extension of products e.g. baked cereal products like bread. One problem is recontamination of products after heat treatment or baking. This could be solved using in-pack decontamination. |
What can it NOT be used for?
| Products | Products packed in such a way that IR radiation cannot reach all surfaces, for example stacked products. |
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| Operations | Processes/operations with very high temperatures might induce mechanical changes of the plastic films. |
| Other limitations | Expansion of the package during IR heating, due to the steam released from the product, could be a problem.
Also, condensing on the package surface during cooling phase and moistening of the bread surface could be a possible problem with this method. |
| Risks or hazards | There is a possible risk for migration of compounds from the packaging material. |
Implementation
| Maturity | Initial laboratory studies have been done but further evaluations are needed before using the materials in the industry for in-pack treatment. |
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| Modularity /Implementation | Modular. |
| Consumer aspects | There is a growing demand for safer and better quality food products. |
| Legal aspects | No legal aspects. |
| Environmental aspects | IR heating has low energy consumption, is easy to control and relatively inexpensive. In-pack processing reduces waste in the food chain due to reduced recontamination and spoilage. |
Facilities that might be interesting for you
Further Information
| Institutes | SP |
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| Companies | Kontiki Group AB, Amcor Flexibles, Flextrus |
| References | 1. Borjesson, M. (2010) Selection of packaging material suitable for infrared heating of food. Master of Science thesis in the master degree programme, Materials and nanotechnology. Department of Chemical and Biological Engineering division of Polymer technology, Chalmers University of Technology.
2. Ozen, B.F., Floros, J.D. (2001) Effects of emerging food processing techniques on the packaging material. Trends in Food Science & Technology, 12, 60-67. 3. Staack, N., Ahrné, L., Borch, E., Knorr, D. (2008) Effect of infrared heating on quality and microbial decontamination in paprika powder. Journal of Food Engineering, 86, 17-24. 4. Staack, N., Ahrné, L., Borch, E., Knorr, D. (2008) Effects of temperature, pH, and controlled water activity on inactivation of spores of Bacillus cereus in paprika powder by near-IR radiation. Journal of Food Engineering, 89, 319-324. |