Researchers have created a special coating made of Chitosan that helps avocados last longer on the shelf. There’s also an imaging technique that can be used to predict how long they’ll stay fresh. This new method was found to keep avocados at their best for up to 12 days, plus there’s a machine-learning model that helps find out how good the quality of the fruit is.
Avocadoes are very popular as they can be placed on toast, blended into guacamole or mixed into salad dressings. The tricky part is that they have a short life-span; going from green and hard to brown and mushy quickly. Fortunately, scientists created a coating which extends the life of avocados. They also invented an imaging system which helps figure out how long it will last.
When people want to check if their avocados are ripe, they give them a gentle squeeze and see if the avocado feels a bit spongy. Producers do this as well to decide which avocados can last until they show up in grocery stores, but still some of them get ruined before that happens. That’s why researchers created ways to help delay their ripening, one such way is by using something called 1-methyl-cyclopropene (1-MCP). Recently, scientists found out that a material made from shellfish exoskeletons, called chitosan, can act like an antiviral when it’s sprayed on fruits like avocados. So some experts wanted to figure out how well these two methods work at keeping avocados fresh for longer and seeing the effects on their overall quality.
The researchers tested with different treatments for mature Hass avocados. Some were treated with only plain air and others got a water-based solution that contained chitosan. Then, they chilled the treated and untreated avocados at 41 degrees Fahrenheit for 21 days before moving them to room temperature like what you find in grocery stores – until they became rotten. Those without any treatments, as well as those treated with 1-MCP or 1% chitosan coating, were good to eat and ripe after 6 days. While the ones treated with 1.5% chitosan-based coating last longer (12 days), but had some strange spots on their skin surface when it’s ripe. The researchers think these odd findings can mean that the chitosan coating needs more improvement in the future.
To find out how avocados ripen and predict their remaining shelf life, the researchers used special cameras to take pictures of the fruit in different colors and measured reflectance data. This was then compared to a number of factors like firmness, color, oxygen consumption, and weight loss using computer models. Finally, two machine learning models were found that describe the changes seen during avocado ripening and can predict its shelf life. The hope is that this coating technique will help make sure avocados stay fresh longer!
This article has been published in the journal ACS Food Science & Technology on May 3rd, 2023. It is written by Angie Homez-Jara, Henry Cardenas-Roa, Miguel Montealegre, Loong-Tak Lim, Maria G. Corradini, Henry Alexander Váquiro-Herrera and Angelica Sandoval-Aldana. This paper discusses postharvest treatments for Hass Avocados (Persea americana Mill.) as well as methods to estimate their quality using a tool called Hyperspectral Imaging (HSI).
The writers of this passage were supported by the Government of Tolima, a research program in Canada, scholarships from Ontario and an educational platform.
