Most people have experienced the disappointment of slicing into an avocado only to find it hard as a rock. But don’t blame the farmers because unlike many other fruits, avocados do not ripen while they are still hanging on the tree. Therefore, there is no use in harvesters giving the all the avocados on the trees a squeeze.
Some simple, but unreliable methods include visual signals like size and the skin of cultivars like ‘Hass’ may start to go from green to purple. But the avocado industry needed a more reliable method to test maturity. This solution used the dry matter content of the fruit as an indicator of maturity. The dry matter content is comparable to the oil content of the fruit. As the fruit mature, oil content increases. It was determined that an oil percentage of 8% was required for an avocado to reach maturity. Sample fruit are taken from the tree, dried and the resulting weight, which is directly related to oil content, was determined.
This is rather counterintuitive. So, a more conservative method was developed. This method is known as Near Infrared Spectroscopy (NIR). This technique illuminates the skin of a fruit with bright light and a device measures the spectrum of light which is reflected off the skin. There is a correlation between the reflected spectrum and the amount of dry matter, and therefore oil, within the fruit. The results are received immediately and handheld NIR guns can be easily transported in orchards and placed on packing lines in the packhouse. This technology is especially helpful to exporters.
Accurate maturity estimations mean that the less mature fruit can be sent to far off places and will not ripen during the journey. The more mature fruit can be saved for shorter journeys and the local markets.
And there you have it, some of the ways that an avocados maturity can be determined. How useful would an NIR gun be in our grocery stores, there would be no more bruised and battered avocados being sacrificed in order to find the perfect maturity!