Papaya, cucumber, cilantro, jalapeño peppers, and tomatoes are some of the Mexican products that the United States has included in a list of restrictions due to alleged health risks.
Avocados, however, are treated with a disinfectant formula based on hibiscus flowers, as Mexico exports seven out of 10 of these fruits to the US market, according to Sagarpa's 2017 Agricultural Food Atlas.
This formula was developed as the avocado, like other crops, is exposed to being contaminated with salmonella, typhoid or E.Coli at each stage of its production: cultivation, transport, storage, and final sale.
"A person only needs to have contact with 10 Salmonella bacteria to get sick, and the microorganisms have developed resistance to certain antibiotics for use in food, human and veterinary medicine," said the researcher at the Autonomous University of the State of Hidalgo (UAEH), Javier Castro Rosas.
Mexico produces just over 1,520,000 tons of avocado each year, i.e. 30 percent of the world's avocado production, which makes it the leading producer and exporter of avocados internationally.
15 years ago, Javier Castro Rosas, together with other researchers and bachelors and masters of the UAEH, began studying the antimicrobial properties of the hibiscus flower to combat the strains of salmonella, typhoid and E.Coli in avocado.
According to him, he began this research after having analyzed different samples of avocado skin obtained in some markets of Pachuca, Hidalgo, and discovering that eight out of 100 samples had some of these pathogenic bacteria.
The researcher said that the market had different commercial solutions based on colloidal silver or chlorine that eradicate the bacteria after several minutes in water, but that unfortunately most of them were deficient, contrary to what their label indicates.
The results of his tests showed that four or five droplets of sodium hypochlorite diluted in water, as recommended by the Ministry of Health, were only able to eliminate up to two thousand of 10 thousand pathogens in the fruit.
"There was a reduction of one thousand or two thousand dangerous cells, but there still is a very high danger," the scientist said, adding that the hibiscus flower was found to kill up to 80 percent of them.
According to the research of the flower's calyx, he said, the Creole and White varieties have a high microbial potential. "The latter has higher concentrations of hibiscus acid that allowed us to achieve our goal."
The hibiscus flower, however, wasn't strong enough to achieve their goal. Thus, the researchers added acetic acid (vinegar), citric acids from lime, and other substances of natural origin to their formula to completely eliminate the bacteria from the avocado.
The researchers are in the process of registering a patent of the compounds found and the powerful disinfectant at the Mexican Institute of Industrial Property (IMPI), with the intention of generating business opportunities.
The researcher and his team have also developed specific formulations to disinfect mango, strawberry, chili, tomato, coriander, and other products.