Persistence of aflatoxin during the fermentation of soy sauce

Area of Science:

• Food microbiology
• Mycology
• Toxicology

Background:

• Aflatoxins are toxic secondary metabolites produced by certain Aspergillus species.
• Soy sauce fermentation involves complex microbial interactions.
• Contamination of food products with mycotoxins is a significant concern.

Purpose of the Study:

• To investigate aflatoxin production by Aspergillus parasiticus and Aspergillus oryzae during soy sauce fermentation.
• To assess the degradation of aflatoxin under specific fermentation conditions.

Main Methods:

• Fermentation of soy sauce using Aspergillus parasiticus NRRL 2999 and Aspergillus oryzae.
• Monitoring aflatoxin production during fermentation.
• Incubation of fermented soy sauce with and without Lactobacillus delbrueckii to evaluate aflatoxin degradation over 6 weeks.

Main Results:

• Aspergillus parasiticus NRRL 2999 produced aflatoxin during soy sauce fermentation.
• Aspergillus oryzae did not produce detectable levels of aflatoxin.
• Aflatoxin degradation was negligible within 6 weeks in the absence of Lactobacillus delbrueckii.
• The presence of Lactobacillus delbrueckii significantly enhanced aflatoxin degradation.

Conclusions:

• Aspergillus parasiticus poses a risk for aflatoxin contamination in soy sauce.
• Lactobacillus delbrueckii plays a crucial role in mitigating aflatoxin accumulation in soy sauce.
• Co-cultivation strategies involving Lactobacillus delbrueckii may be beneficial for ensuring the safety of fermented soy products.