Mycobiota of ground red pepper and their aflatoxigenic potential

Area of Science:

• Food Science
• Mycology
• Analytical Chemistry

Background:

• Ground red pepper is a widely consumed spice.
• Fungal and mycotoxin contamination of food products is a significant public health concern.
• Previous studies have indicated potential for fungal contamination in spices.

Purpose of the Study:

• To assess the fungal and mycotoxin contamination levels in ground red pepper from Korea.
• To identify predominant fungal genera and species in contaminated samples.
• To evaluate the mycotoxin-producing potential of isolated fungi, particularly Aspergillus species.

Main Methods:

• Collected 30 ground red pepper samples from 15 manufacturers in Korea.
• Determined total fungal counts using potato dextrose agar.
• Identified fungal genera and species through culture-based methods.
• Quantified aflatoxins, ochratoxin A, and citrinin using ultra-performance liquid chromatography (UPLC).
• Screened Aspergillus isolates for aflatoxin production genes (norB-cypA) via PCR.
• Confirmed aflatoxin production by positive isolates using UPLC.

Main Results:

• Total fungal counts ranged from 0 to 7.3 × 10³ CFU/g.
• Aspergillus was the most prevalent genus, followed by Paecilomyces, Rhizopus, Penicillium, Cladosporium, and Alternaria.
• Ochratoxin A was detected in three samples (1.03–2.08 μg/kg); aflatoxins and citrinin were not detected in the initial analysis.
• PCR identified the aflatoxin gene in 10 Aspergillus flavus isolates and one Aspergillus sp.
• UPLC confirmed aflatoxin production by these 11 isolates, with levels ranging from 146.88–909.53 μg/kg.

Conclusions:

• Ground red pepper in Korea is susceptible to fungal contamination.
• Certain Aspergillus isolates possess the genetic potential and capability to produce aflatoxins.
• Continuous monitoring of ground red pepper for toxigenic fungi is crucial for mitigating mycotoxin risks.