Pilot Scale Test In Preparation And Application In Preservation Of Food Grape Antimicrobial Peptide

Antimicrobial peptide(AMP)is an antimicrobial polypeptide against pathogenic and spoilage bacteria,which is widely recognized as natural biopreservatives,and has the potential to take the place of traditional chemical preservatives.The pilot scale test in preparation and application in Preservation of the AMP produced by Brevibacillus laterosporus S62-9 were investigated in the present work.Based on fermentation parameter of 5 L fermentation tank,this paper studied the pilot scale test of 30 L fermentation tank and optimized inoculum amount and dissolved oxygen concentration.The optimum fermentation conditions were as follows:60-70%dissolved oxygen concentration,5%inoculum amount,at 32℃.Under the above conditions,antibacterial activity of fermentation liquor could reach from 1080 AU/mL to 1 373 AU/mL and fermentation time was shortened from 20 h to 12 h.Amplification test of the AMP extraction process was studied in this paper by comparing three different drying methods such as freeze-drying method,vacuum drying method and spray drying method.The results showed that spray drying method better than other methods due to the short time-consuming,low energy consumption and high recovery of the AMP.Antibacterial activity of the AMP on bacterium was studied in the chilled pork and chilled beef.Its antibacterial activity in the chilled pork and chilled beef was stable during strorage.The AMP preservation solution of 640 AU/mL could extend the shelf life of chilled pork six days and extend the shelf life of chilled beef five days.Preservation effect of the AMP in milk and milk drinks was also studied in this paper.Its antimicrobial activity in milk was stable during strorage.The AMP of 320 AU/mL could effectively inhibit the growth of pathogens and spoilage bacteria in milk.By adding the AMP of 320 AU/mL,the shelf life of milk drinks was extended from 18 to 30 days.