Scientists at the Department of Food Research (DIA) at the Faculty of Chemistry (FCQ) of the Autonomous University of Coahuila (UAdeC), have developed a natural bioactive coating to prolong the shelf life of Hass avocados.

The project, which was coordinated by Dr. Cristobal Noe Aguilar Gonzalez, a research professor at the DIA and level III member of the National Research System (SNI), aimed to assess the effect of a bioactive coating, that was based on Candelilla wax and the leaf extract of Larrea tridentata, on the shelf life and quality of the Hass avocado (Persea americana Mill).

"The goal of this project was to develop a natural coating that would extend the shelf life of avocados, i.e. that would preserve its quality, characteristics and optimum consumption state for a longer period at its point of origin, or that would allow it to arrive at distant markets, mainly Japan, maintaining its quality," stated Jorge Alejandro Aguirre Joya, who conducted this research in his doctoral thesis in science and technology in food at the Faculty of Chemical Sciences of the UAdeC and collaborated in the project.

The researcher said the coating also inhibited the growth of phytopathogenic fungi that cause deterioration and loss of quality in the fruit.

"We managed to develop a coating that, when compared to the commercial coatings, increases the shelf life for a longer period and that allows us to inhibit the development of these plant pathogens," said the scientist.

Currently there are different techniques to extend the commercial life of avocados, such as vacuum packaging, cold storage, and modified atmosphere; however, they only preserve the product.

"There are some commercial options to extend the shelf life of avocados. However, none of them focuses on inhibiting the growth of microorganisms or the damage they cause. There are pests, such as the Colletotrichum gloeosporioides and the Alternaria alternata, that can cause up to 46 percent of crop losses," Dr. Aguirre Joya said.

According to the specialist, the project is an alternative to solve the problems faced by avocado in its post harvest, such as decreased quality and the damage caused to the fruit by the Colletotrichum gloeosporioides and the Alternaria alternata pests .

"The avocado is one of Mexico's main crops. We know that Mexico is the number one producer and exporter of this product and that it currently has big post harvest problems because of these microorganisms and because of quality loss, which is reflected in economic losses, once the product reaches markets, such as Asia or Europe."

More applications
Dr. Aguirre Joya said that this coating was especially designed for the Hass avocado, according to its characteristics and needs. However, researchers can generate similar coatings that are adapted to the characteristics of other fruits.

"It can be extrapolated to other fruits, adapting it to the surface characteristics of those fruits. It depends on every situation and what is required. We have some fruits, like the tomato, that has a lot of losses in post-harvest; the apples are a very important product in the region, while the melons are important in the Laguna region, among other fruits."

This development is aimed at producers, packers, and exporters of avocado. It was mainly thought of for the national market, but it can be applied anywhere that produces, stores, or transports avocados.

"We are waiting to finalize this project, transfer it and make it a reality that can be a competitive advantage for the country. We already are the number one producer and exporter of avocado, but we can still raise our level of competitiveness and product quality," said Dr. Aguirre Joya.