Identification of biofilm-forming bacteria and remove of the Proteus biofilm in chilled pork

Microorganisms are prone to form bacterial biofilm on the equipment surfaces in chilled pork, which causes meat spoilage, foodborne diseases prevalence and food poisoning. This article investigated the formation law of microflora from chilled pork on the surfaces of glass and stainless steel at different temperatures, and isolated and identified biofilm-forming bacteria, and removed biofilm with sodium hypochlorite and ultrasonic method. The results showed that bacteria biofilm reached the maximum at 10, 6 and 3 d at 4, 15 and 26℃, respectively, and the amount of biofilm formed on stainless steel was greater than that of glass. A total of 9 biofilm-forming strains were isolated and identified, including Proteus vulgaris, Streptococcus, Pseudomonas and so on. By sodium hypochlorite soaking, the removal effects on Proteus biofilm on stainless steel and glass surfaces were significantly (p<0.05). The removal effects of 200, 400 and 600 mg/L sodium hypochlorite solution soaking for 5 min could reach 98%. 100 kHz ultrasound 1 min combined with 400 mg/L NaClO solution soaked in 5 min cleanup effect was up to 99%, that could be better than 400 mg/L NaClO solution and ultrasonic alone.