Modified Atmosphere Packaging Gets a New QA Tool for Fresh-Cut Produce

Measuring only CO2 and O2 in Modified Atmosphere Packaging for produce leaves out an important key marker of produce freshness: Ethylene (C2H4). C2H4 production is a natural part of the plant life cycle, a complex hormone that varies not only between species, but from crop to crop of the same species.

C₂H₄ has been called the plant “death hormone”, because as part of the natural plant life cycle it not only accelerates growth and plant maturity, but also aging and decay. Whenever plant tissue is injured it begins producing more C₂H₄, and this is where it becomes an issue for produce processing.

Preparing fresh-cut products causes damage to plant tissues, which naturally increases C₂H₄ production and reduces shelf-life. C₂H₄ has been noted to particularly spike in cut kiwifruit, winter squash, tomatoes, papayas and strawberries according to Fresh-Cut Fruits and Vegetables: Science, Technology, and Market (ed: Lamikanra, 2002). Cut produce can continue to produce C₂H₄ up to week later. 

To make things more complex, levels of C₂H₄ will vary across harvests of the same crop—it all depends on the maturity of the plant when it was cut. But C₂H₄ doesn’t have to be a wild card in produce management, now that Felix Instruments has developed the F-950 Handheld Ethylene Analyzer. With its high C₂H₄ sensitivity, combined with traditional respiration monitoring of CO₂ and O₂, the F-950 gives a new level of quality control to the MAP process.