Preparation And Performance Optimization Of Pea Protein Antibacterial Film

In recent years,as people's health needs and environmental awareness have increased,more and more scholars have studied the use of green,environmentally friendly,biodegradable biofilms to replace plastics.Pea protein is an ideal environmentally friendly packaging material due to its wide source and good film formation.However,due to its nutrient-rich nature,pea protein is easily eroded by microorganisms,which greatly limits its application in degradable packaging materials.The study found that the addition of antibacterial substances to the protein film can effectively inhibit the growth and reproduction of microorganisms on the surface of packaged foods,and improve the shelf life and safety of foods.The inhibitory strength and inhibition spectrum of different bacteriostatic substances are different.Selecting appropriate antibacterial substances for compounding can make up for their respective deficiencies,and thus play a synergistic antibacterial effect.In this study,pea was used as raw material to extract pea protein isolate by alkali-soluble acid precipitation method.The optimum conditions for the preparation of pea protein membrane were optimized by single factor and orthogonal experiments.Add rosin extract(Ros)and honey(Hon)to prepare pea protein bacteriostatic membrane,study the addition of rosemary extract or honey and the two pairs of pea protein membrane physical properties,chemical structure,total phenolic content,anti-The effect of oxidative activity and bacteriostatic performance.The main findings are as follows:(1)The optimal process conditions for the preparation of pea protein membrane were determined by single factor and orthogonal test: protein concentration 7%(w/v),p H value9.0,glycerin addition amount 50%,heating temperature 85°C,heating Time 25 min.Under these conditions,the pea protein film has a tensile strength of 4.51 ± 0.02 MPa.(2)The pea protein membrane,soybean protein membrane and peanut protein membrane were prepared under the same conditions.The performance of the three protein membranes was as follows: the soybean protein membrane had the best comprehensive performance,good mechanical properties and high transparency;the pea protein membrane was highly water-soluble.However,the water repellency is good;while the peanut protein cannot form a film under this condition.(3)Adding rosemary extract and honey gradually increased the thickness of the pea protein membrane(p>0.05).(4)With the increase of the amount of rosemary extract or honey added,the tensile strength and elongation at break of the protein film were significantly decreased(p<0.05).(5)The addition of rosemary extract caused the water vapor transmission rate of the protein film to increase first and then decrease,while the solubility and swelling index decreased significantly(p<0.05);the water vapor transmission rate of the protein film was added by adding honey.Significantly elevated(p < 0.05),when the amount of honey added was 1.0% ? 4.0%,the solubility of the protein membrane increased significantly(p <0.05).The combination of the two significantly reduced the swelling index of the protein membrane(p < 0.05)compared to the control membrane.(6)The addition of rosemary extract significantly increased the opacity of the protein membrane(p<0.05);while the addition of honey was 2.0%-4.0%,the opacity of the protein membrane was significantly higher than that of the control membrane(p< 0.05).The opacity of the compounded membrane was significantly increased(p < 0.05).(7)With the increase of rosemary extract or honey addition,the brightness of protein film gradually decreased(p>0.05),and the a* value and b* value increased significantly(p<0.05).The brightness of the compound membrane was significantly reduced(p<0.05),and the a* value and the b* value were significantly increased(p<0.05).(8)The addition of rosemary extract,honey and the combination of the two did not significantly change the chemical structure of the protein membrane(p>0.05).(9)The total phenolic content and DPPH free radical scavenging rate of rosemary extract,honey and both protein membranes were significantly increased(p<0.05).(10)Adding 0.5%?0.7% of rosemary extract or 3.0%?4.0% honey protein membrane has antibacterial effect on Escherichia coli and Staphylococcus aureus.The rosemary extract and the honey compound have a synergistic effect on the bacteriostasis of the pea protein membrane.In summary,the composite membrane has better physical properties,chemical structure,antioxidant and bacteriostatic properties than rosemary extract or honey protein membrane.In combination with various indicators,when 0.3% rosemary extract + 2.0%honey is added to the protein film,the pea protein film has good performance and has certain anti-oxidation and antibacterial ability,and is suitable for food preservation and pea protein film.There's important meaning.