Incorporation of bacteriocin produced by Bacillus velezensis BUU004, plant extracts and their combination for controlling food spoilage bacteria in dried, seasoned and crushed squids

Abstract

Traditional seafood-based product is one of popular cuisines in Thailand and easily susceptible to contamination of pathogenic and spoilage bacteria, thereby representing a serious risk of food-borne infection. A novel effective alternative technology is required for enhancing biosafety quality along with shelf-life extension of seafood products. This study aimed to evaluate preservative potential of naturally occurring compounds on spoilage bacteria in dried, seasoned and crushed squids. The squids were divided into 4 treatments including supplementation of 1) sterile distilled water (control), 2) a semi-purified solution containing bacteriocin from B. velezensis BUU004 (SPS-BV; 800 AU/mL), 3) a mixture of lemongrass and hot pepper extracts (160 mg/mL) and 4) a combination of the SPS-BV (800 AU/mL) and the mixed herb extracts (160 mg/mL), and then stored in a refrigerated condition for 28 days. Strategies of the tested-additive administration included a single addition at beginning of trial and addition of the additives every 14-day of storage. A single addition of the three tested additives was shown to be unlikely to decrease total viable count (TVC) in dried squids. In contrast, the antibacterial activity was more evident in dried squids supplemented with the SPS-BV or the novel combination with every 14-day addition observed by 21.8% and 14.1% TVC decrement, respectively. Our results indicate that the SPS-BV and the novel combination have a preservative potential for controlling the growth of spoilage bacteria in dried seafood products. However, due to their degenerative antibacterial activity in dried squids during storage, a development of intelligent active and controlled release packaging technologies that can deliver the antimicrobials into the seafood systems over prolonged periods is further required to improve quality and safety of traditional seafood products in Thailand.