| Contents Low-temperature meat products are the main meat products in developed countries,but the development in our country is restricted by many factors.Low temperature meat products are easy to deteriorate in the process of processing,selling and eating.The shelf life of the products is very short,especially the Listeria monocytogenes,which is easy to proliferate in the process of product storage and transportation.In order to prolong the shelf life and food safety and quality of products,adding preservatives is the most effective measure.At present,chemical preservatives are widely used in the industry.However,the unsafe factors of chemical preservatives have brought great risks to the health and safety of consumers.To find an effective and harmless preservative has become the common goal of many food producers and researchers.In this study,three commercial natural antimicrobial agents were selected.Their constituents were extracted from natural plants.The antimicrobial properties of these three natural antimicrobial agents and their inhibitory effects on Listeria monocytogenes were studied.A series of research results are obtained.The specific research contents and results are described as follows:1.Using Listeria monocytogenes,a common pathogenic bacteria in low-temperature meat products as indicator.The minimum inhibitory concentration of natural antibacterial agents was determined by Agar plate dilution method.The results showed:The minimum inhibitory concentration of three natural antimicrobial agents is T10-10mg/ml、DV—10mg/ml、T4N-4mg/ml.2.Study on antibacterial properties of bacteriostatic agents:Natural bacteriostatic agents were added to liquid medium TSB according to a certain proportion,Inoculating Listeria monocytogenes,microorganism indexes were detected by sampling periodically.The results showed that the growth of Listeria monocytogenes was significantly inhibited by three natural antimicrobial agents in liquid medium.The bacteriostatic effect of T10、DV、T4N was not different from that of traditional chemical preservatives,even better than that of traditional chemical preservatives.In the evaluation of the bacteriostatic properties of T10、DV、T4N,T 10 was the best in terms of it stability and bacteriostatic effects.The second was DV and T4N,but the combination of T10 and DV had better antimicrobial effect and stability than the single use of three natural antimicrobial agents.3.Research on the application of product:Natural bacteriostatic agent was used in low temperature chicken sausage,inoculated with Listeria monocytogenes,stored at 4℃,and measured microorganism index by sampling regularly;Some of the uninoculated samples were used for the detection of physicochemical indexes and the total number of bacteria.The results showed that the natural bacteriostatic agents DV and T10 D V had excellent inhibitory effect on the growth of Listeria monocytogenes in low temperature chicken intestines.The bacteriostatic ability was even better than that of chemical preservative in the first 30 days of storage.The results showed that the combination of natural bacteriostatic agent T10 and DV had a beneficial effect on the color and pH of low temperature chicken sausage.It shows good color and texture,The results showed that the combined use of natural bacteriostatic agent T10 and DV could prolong the total number of bacteria in low temperature Chicken sausage by 25 days before exceeding the national limit.4.By compounding the existing natural bacteriostatic agent T10 and DV,and synthesizing the test results of three stages,we find a natural bacteriostatic product,T10+DV,which can replace nitrite as a hair color and color protecting agent and has good antibacterial effects. |
