Green pistachio shell is effective in reducing aflatoxin contamination
The results of a study showed that the addition of pistachio shell and hexane and aqueous extracts prevents the growth of aflatoxin-causing fungi.
The results of Dr. Reza Rousta Azad, a researcher at Sharif University of Technology, who has studied the effect of pistachio green peel on reducing aflatoxin contamination, are as follows: Aflatoxins are the most potent natural carcinogenic compounds.
On the other hand, if contaminated food is used, these toxins accumulate in the liver and produce liver cancer with hepatitis B. These toxins are produced by various foreign species such as Aspergillus Flavus.
It is worth mentioning that this fungus was grown in different stages, harvested and stored on many agricultural products, including pistachio fruit, and infects them.
Many agricultural products, especially pistachio green bark, are naturally resistant to these pests. It is worth noting that naturally A. Flavus sprays can not pass through the cuticle layer in pistachios and contaminate the fruit.
But if this shell is injured, the fungal sprays penetrate into the fruit, grow and produce toxins.
According to this study, healthy pistachios were collected from orchards, their green shells were carefully separated from pistachios, and pistachio kernels were dried and ground at 80 ° C for 48 hours.
Also, A. Flavus fungus spray was used for experiments, which were examined in liquid and solid culture media. The results of this study showed: the rate of infection in healthy pistachios is much less than injured pistachios.
Also, the amount of sputum in wounded pistachios is much higher than healthy pistachios. On the other hand, experiments show that the contamination on the outer surface of the shells was much less than the inner surface, and this indicates that the cuticle, the substance that prevents the penetration of contamination, is located in the outer layer of the shell.
These results add: with increasing the concentration of milled shell in pistachio-agar medium, the growth rate of the fungus decreases and at a concentration of 5%, the highest inhibition is observed.
Inhibitors in the green shell of pistachios prevent the growth of fungi. According to this study, with increasing the concentration of shell in the culture medium, the role of the cuticle decreases in comparison with the nutrients in pistachio and the diameter of the fungus halo increases with increasing the concentration of the shell in the culture medium.
On the other hand, adding green pistachio shell after extraction with hexane, ethyl acetate, acetone and methanol to pistachio-agar medium has no effect on reducing fungal growth, but reduces the production of aflatoxin toxin.
Then, after extracting the shell using water solvent, the amount of toxin production increases at once. In fact, it seems that after extraction with water, all inhibitors are removed from the shell and the organic matter remaining in the shell is the reason for the increase in toxin production.
Another part of this study indicates that by adding hexane extract with a concentration of 3% to pistachio medium, agar not only significantly reduces the growth of the fungus but also significantly reduces sporulation and production of aflatoxin toxin.
The results show that extracts extracted from pistachio shell by ethyl acetate, acetone and methanol solvents do not play a significant role in reducing fungal growth and aflatoxin production.
After adding the extract extracted from the upper shell of pistachio using water solvent to pistachio agar medium, although this extract can not prevent the growth of A. Flavus, but the diagrams of this study show that it effectively sprays and produces The toxin reduces aflatoxin.
In conclusion, the aqueous extract completely prevents the growth of A. Flavus in liquid culture medium, although this extract has little role in treating the culture medium infected with the fungus and removing aflatoxin toxin from the medium.
Also, the effect of aqueous extract in the treatment of contaminated culture media showed that although this extract prevents the production of more toxins, but it is not very effective in eliminating the toxins produced.