Biosafety, bacteriological quality and strategy of biopreservative administration for controlling spoilage bacteria in Thai traditional dried seafood products

Biosafety has currently become an important public health issue in seafood industry of Thailand. In order to enhance quality of seafood products, three phases of study were established. In the first phase, biosafety of traditional processed squid sold in Chon Buri province, Thailand compiled from literatures between 2002 and 2019 was evaluated. The squid products represented a health hazard due to 86.5% samples, having total viable count (TVC) over the allowable limits imposed by Thailand and international food administration agencies. In the second phase, bacterial contamination during multiple steps related to dried seasoned squid preparation and storage was determined. TVC were low at approximately 102 CFU/g during a multi-step of preparation, and increased significantly (P < 0.05) to 103 CFU/g in post-prepared products during 25-day storage. Lastly, a novel preservation strategy was developed. A combination of partially purified solution from Bacillus velezensis BUU004 with nisin and the mixed herb extracts from hot pepper and lemongrass exhibited the strongest antibacterial efficacy observed by a significantly (P < 0.05) low TVC in the post-prepared squid within allowable limits recommended by the food administration authorities. This study suggests that the novel mixture has a preservative potential to improve biosafety of dried seafood products.