The ambient conditions in the supply chain for perishable goods like climacteric fruits are of great importance. On the one hand, ambient conditions in a container or transport compartment are a prerequisite to maintain the freshness of the transported perishable cargo while, on the other hand, by controlling the conditions, a specific behaviour of the commodity—like reduced metabolism and hence respiration—can be ensured. Low temperature remains the key to maintain good fruit quality and it is mandatory to ensure that the cold chain is not interrupted during transport. A very good example of the consequences of changes in ambient conditions is the transport of strawberries. Just 1 h storage at increased temperatures of only a few degrees can reduce the shelf life or edibility of the fruit by a day. Besides the temperature, the composition of the ambient air has considerable influence on the eventual fruit quality and, consequently, on the shelf life of the transported perishable cargo. Modified and controlled atmosphere (MA/CA) is the key to extend the shelf life of fruits . Besides CO₂ and O₂, ethylene is the most important gas to be monitored and controlled in the supply chain of fruits.
Less than 1 part per million (ppm) by volume of ethylene gas is sufficient to trigger the ripening process of climacteric fruit . Hence, ethylene gas is considered a ‘phytohormone’. Thus, knowing the concentration of ethylene gas in storage rooms is important regarding two aspects. Firstly, the ethylene concentration indicates the stage of fruit ripening , and countermeasures like venting fresh air can take place when the concentration is approaching a critical range, e.g. 1 ppm. Secondly, by knowing the ethylene concentration, a prediction of the remaining shelf life is possible. Therefore, it is necessary to analyse the rise of ethylene in the pre-climacteric stage of fruit development, when the ambient concentration is below 1 ppm. Hence, ethylene should be measured with a resolution of 50 ppb or better. As in this low concentration range many other organic substances will be present, any potential sensing method requires good sensitivity as well as good selectivity. Furthermore,the C2H4 gas detectors must be small as well as sufficiently robust for usage in a container or other transport compartment.
There are several gas detectors on the market, Safegas can help you selecting the correct model for you application. We use the Alphasense PID sensors from England, one of the newest and most accurate technologies available today, this process can ionize molecules using ultraviolet light, and then measure the electron levels and their flow. In doing so, it allows to be used in the humidity cold storage room and very sensitive & high precision, which the lowest detection concentration level can be 0.001ppm(1ppb). Attached are the pictures of our C2H4 gas detectors used in Indonesia for your reference.