Isolation of an Antioxidative Substance Produced by Aspergillus repens

Area of Science:

• Microbiology and Natural Product Chemistry
• Food Science and Technology

Background:

• Food spoilage is often caused by oxidation, necessitating effective antioxidants.
• Katsuobushi, a traditional Japanese food, is susceptible to oxidative degradation.
• Microbial fermentation can yield novel antioxidant compounds.

Purpose of the Study:

• To isolate and identify antioxidant compounds from Aspergillus repens MA0197 culture liquid.
• To evaluate the antioxidant capacity of the isolated compounds.
• To explore the potential of these compounds as antioxidants in food products like Katsuobushi.

Main Methods:

• Extraction and fractionation of the culture liquid from Aspergillus repens MA0197.
• Ferric thiocyanate and TBA assays to evaluate antioxidative activity.
• Chromatographic purification and structural identification of the active compound.

Main Results:

• The acidic fraction of the extract exhibited significant antioxidative activity.
• Neoechinulin A was isolated and identified as the primary active substance.
• Neoechinulin A displayed higher antioxidant activity than alpha-tocopherol.

Conclusions:

• Neoechinulin A is a potent antioxidant produced by Aspergillus repens MA0197.
• This compound shows promise as a natural antioxidant for food preservation, particularly in Katsuobushi.
• Further research into Neoechinulin A's application in food systems is warranted.