Evaluation of citrus flavonoids against Aspergillus parasiticus in maize: Aflatoxins reduction and ultrastructure alterations

Flavonoids Modulate the Accumulation of Toxins From Aspergillus flavus in Maize Kernels

“…Flavonoids and aflatoxin production have been studied by using Aspergillus parasiticus to inoculate kernels treated with a flavonoid mixture (0.39-mM naringenin, 0.24-mM neohesperidin, and 0.4-mM quercetin), which showed an 85-100% decrease in aflatoxin accumulation (Pok et al, 2020). Similar studies done with A. flavus incubated with anthocyanidins and related flavonoids showed inhibition of aflatoxin B1 production (Norton, 1999) and inhibition of growth (Li et al, 2019).…”

“…Similar studies done with A. flavus incubated with anthocyanidins and related flavonoids showed inhibition of aflatoxin B1 production (Norton, 1999) and inhibition of growth (Li et al, 2019). TEM images of A. parasiticus treated with each flavonoid from the mix showed fungal damage such as, naringenin treatment-stimulated formation of lipid vesicles; neohesperidin treatment led to degradation or rupture of plasmalemma cell wall deformation and vesicle formation; quercetin treatment; agglutination of fibrillar layer, formation of dense grains in the inner wall, disruption of nuclear membranes, and formation of vesicles (Pok et al, 2020). Combination of the flavonoid mix led to greater degradation of membranes, organelles, and cytoplasm content (Pok et al, 2020).…”

Green extraction of polyphenols from citrus peel by-products and their antifungal activity against Aspergillus flavus

“…Therefore, the most abundant compounds in mandarin extracts may not be the most active, but other less abundant compounds may play the more the important role in antifungal properties. We can also not rule out synergistic effects between the compounds ( Pok et al, 2020 ).…”

“…One study showed that purified flavanones (naringin at concentration of 68 mg mL −1 , hesperidin at 153 mg mL −1 and neohesperidin at 153 mg mL −1 ) could inhibit growth of A. flavus by 33–41% ( Salas, Céliz, Geronazzo, Daz, & Resnik, 2011 ). These polyphenols are proposed to inhibit the fungus by altering the ultrastructure of the fungal cell walls and endomembrane system ( Pok et al, 2020 ). In addition, these three flavanones were found to reduce the accumulation of aflatoxin B 1 produced by Aspergillus sp.…”

“…In addition, these three flavanones were found to reduce the accumulation of aflatoxin B 1 produced by Aspergillus sp. by 80% to 100% ( Pok et al, 2020 ). However, there is limited knowledge on the activity of food-grade extracts, which may contain mixtures of polyphenols, as well as other bioactives.…”