What is it?
Nearly everyone has warmed up a cup of coffee, some leftovers, or a TV dinner in a microwave. The same technology can be applied to agricultural processes. Already used in Europe and Japan, microwave processing can be used effectively in agricultural applications; most notably food preservation, pasteurization, and drying.
How does it work?
Microwave heating uses electromagnetic waves in the microwave frequency range to energize molecules in a material or substance, causing the material to heat up. The waves have different frequencies to penetrate different types of products.
What are the most appropriate applications?
Currently, microwave processing is used in smaller-volume applications for pasteurization or food preservation. Drying applications are still in the early stages of large-scale adoption. Microwave processing is used in high-temperature short-time (HTST) sterilization operations where a product is heated rapidly to sterilize. Comparatively, traditional heating processes bring products up to temperature more slowly and for longer periods of time. Research is being conducted to develop larger volume systems, such as a continuous flow pasteurization system for dairy operations, which would further increase processing speed.
What are the savings?
The efficiency of microwave processing applications can be difficult to measure. Compared to electric heating, there are efficiency losses with microwave heating due to converting electrical energy to microwave energy and the absorption of the product. Determining energy savings also often involves comparing different fuel types (i.e. natural gas and electricity). The biggest efficiency gain with microwave processing comes from processing speed. By decreasing processing time, throughput can be increased or operating hours on processing equipment can be decreased, leading to lower energy usage per unit produced.
What are the non-energy benefits?
The main benefit of microwave processing is speed. Microwave pasteurization processes can be four times faster than traditional processes, and drying operations can be four to eight times faster. Rapid temperature sterilization processes can also increase food shelf life. There may also be better vitamin and nutrient preservation, although research is ongoing.
What is the status/availability of the technology?
This technology is available for various industrial processes, with others still being tested. Equipment specifics will be customized to individual operations and costs will vary.
What kinds of incentives/programs are available?
Microwave processing projects would be analyzed in the Custom Rebate program.