Biogenic Amines Control in Bacterial-Type Douchi Using Bacillus velezensis A1: Strain Screening, Process...

Area of Science:

• Food Science
• Microbiology
• Fermentation Technology

Background:

• Biogenic amines (BAs) are compounds found in fermented foods like douchi.
• High levels of BAs can pose health risks.
• Controlling BA production during fermentation is crucial for product safety.

Purpose of the Study:

• To isolate and identify bacterial strains capable of reducing biogenic amine (BA) levels in douchi.
• To optimize fermentation conditions for minimizing total biogenic amines (TBA).
• To validate the effectiveness of selected strains and optimized processes on an industrial scale.

Main Methods:

• Isolation and screening of bacterial strains from naturally fermented douchi based on protease activity and low BA levels.
• Selection of Bacillus velezensis A1 as the representative strain.
• Optimization of fermentation parameters including inoculum size, temperature, and duration.
• Scale-up study using colony-enhanced fermentation (CEF) in a production setting.
• Monitoring of physicochemical properties and TBA levels.

Main Results:

• Bacillus velezensis A1 was identified as a promising strain for reducing TBA.
• Optimized fermentation reduced TBA by approximately 10.80-fold compared to natural fermentation (NF).
• Colony-enhanced fermentation (CEF) on a large scale resulted in significantly lower TBA (38.27 ± 0.13 mg/kg) compared to NF (94.94 ± 2.59 mg/kg).

Conclusions:

• Strain screening and process optimization are effective strategies for reducing biogenic amines in douchi.
• The developed method provides a viable approach for the industrial-scale safe production of fermented soybean products.
• This research offers practical guidance for improving the safety and quality of douchi.