We've all done it. Seen fruit on display in the supermarket. It looks perfect in its shrink-wrap plastic packaging. You can't really feel or smell it but you buy it anyway, only to find that in a day it starts to go rotten. How so?
The reason lies mainly in the way that fruit is forced-ripened during its time in storage wharehouses. Unripe fruit is shipped in cold storage and then to get it looking ripe and nice for the consumer it is treated with ethylene to accelerate the ripening time. Ethylene is a gaseous plant hormone that is naturally produced by fruit in its normal ripening cycle but excessive use of it to force-ripen fruit causes a short shelf-life when it reaches consumers homes.
Research has now come up with a much more accurate way of ensuring that your pears don't putrify and your apples stay attractive after they have been dosed with extra ethylene
A single-chip electrochemical sensor for ethylene monitoring with a detection limit of 200-300ppb (parts per billion) has been created by the Imec and Holst Centre research organisation. The reason is that inexpensive and accurate ethylene sensors would enable better control of the wharehouse ethylene fruit ripening process.
Today’s ethylene detection systems are expensive laboratory table-top devices, not suitable for wharehouse applications, whereas the Imec and Holst Centre’s ethylene sensor is a low-cost electrochemical sensor based on a non-acidic electrolyte that does not evaporate that can be fabricated on cheap substrates such as glass or foil. Recent developments have shown that the ethylene sensor is able to detect 100ppb steps in concentrations below 1ppm, which makes it useful in warehouse applications.
So are these sensors the first step towards intelligent fruit packaging whereby a chip will be included that has been programmed to monitor the fruit's ethylene level but displays that information to the customer as a date by which the fruit will only be fit for the trash can? I have my doubts about that.
So it looks like we have to continue gambling on how long sanitised shrink-wrapped fruit will last in our fruit bowls.