University of California

Ask the Produce Docs (General)


How can we measure the PPM of ethylene in cold storage air?

Category

Cold Storage, Energy

Question

Our team has been utilizing UC Davis’ expertise in the cold storage of perishables and other commodities for the past several years and we have been very successful in implementing what we have learned in our own 50,000 SF (and growing) cold storage facility. We import fresh fruit and vegetables via the regional port and we pride ourselves on keeping the cold-chain of the product intact throughout the inbound / outbound process.

With the wide range of commodities that we are handling, ethylene outputs from the product have become an area of concern for us. We have recently purchased two high quality ethylene scrubbers, and have implemented them in the facility. However, we do not currently have a method of identifying the PPM of ethylene in the cold storage air.


Given your expertise, would you have any idea of a monitor or mobile monitoring device that exists to check ethylene levels? I have been searching for over a week now to no avail. Thanks for the assistance, and I truly appreciate the work you all do for the community. (C.G.)

Answer

Measuring ethylene contamination in storage areas remains a difficult task because the active levels of ethylene are so low (50 parts of ethylene in a billion parts of air, or even less). Several promising new developments for ultra-sensitive measurement using nano-technology have been reported in recent years, but none has yet come to the market place. Measurement at these low levels still requires expensive instrumentation, usually a gas chromatograph ($20,000). Photoacoustic ethylene detection is extremely sensitive and reliable, but the equipment is even more expensive ($40,000). Our recommendations for preventing the effects of ethylene in mixed storage are:

1. Maintain tight control of storage temperatures
2. Store ethylene-producing and ethylene sensitive products in different areas if at all possible
3. Ventilate each storage area with fresh air, drawn in from above the building, with a minimum flow of 1 air exchange per hour.

Cheers,
Michael Reid

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