| Temperature and microorganism would cause food spoilage and lipid oxidation during processing and storage,which not only affect the colour and lustre,but produce unhealthy odor.The process will reduce the inherent nutritional and commercial value of food,and even threaten the human health.Basing on above consideration,the proper addition of antioxidant and preservative is an effective way for improving food quality.At present,artificial antioxidant and preservative(e.g.BHT and potassium sorbate)has been used in abundance in the food industry.With further researches show that the artificial antioxidant and preservative has certain toxicity and carcinogenicity,which could cause adverse effect on the liver,spleen,lungs and other organs with the excessive consumption.It is recognized that the natural antioxidants and preservatives have less toxic side effects,which show higher security than that artificial source.Besides,N-nitroso compounds are kinds of strong carcinogenic chemicals,their precursor compounds such as nitrates and nitrites are widely found in food and its metabolic processes,and commonly used as color former and preservatives in meat processing.Therefore,the screening study for natural active components with antioxidant,antibacterial and inhibiting nitrosamine formation has become the hot spot of current research.Forsythia Suspensa and Scutellaria baicalensis Georgi are traditional Chinese medicines.As famous region drugs of Shanxi province,modern researches show that they have many functions,such as internal heat or fever,antimicrobial and diminish inflammation.Forsythia suspense leaves are the dried leaves of Forsythia suspense,their chemical components are highly similar to the fruit,but the Forsythia suspense leaves resources has not yet been fully exploited.The results showed that Forsythia suspense leaves and Scutellaria baicalensis Georgi have antioxidation and antibacterial activies,and their principal active components are forsythiaside A and baicalin,baicalein.At the same time,it has been reported the scutellaria extracting solution gave fair good preservation effect for strawberry and Chinese royal pear,and the forsythia extracting solution has applied successfully in the preservation process of sausage.Compatibility of Chinese Medicine,the quintessence of the theory of Traditional Chinese Medicine,which could give play to the complementary effects on drug interactions,so that attain the purpose of synergism and attenuation.Thus,the active components of Forsythia suspense leaves and scutellaria with antibacterial,antioxidant and inhibiting nitrosamine formation activities were screened in this paper,and the active components were further complexed for the antiseptic and fresh-keeping of sausage products.The details are as follows:1.The aqueous extraction of Forsythia suspense leaves were initially separated,the separated components and crude extract were analyzed by HPLC,and the total phenols content were determined by UV spectrophotometry.Meanwhile,the antioxidative,antibacterial and the inhibiting effects on the formation of N-nitroso compounds were also studied.The results showed that the content of total polyphenol of Fr2 was 45.40 g/100 g,and the highest among all the components.In addition,Fr2 has most capacities of DPPH· scavenging(IC50 = 3.72 ?g/mL),nitrite removing(IC50 = 38.57 ?g/mL and nitrosamine formation inhibiting(IC50 = 1.06 mg/mL),what's more,it has strong antibacterial effect on staphylococcus aureus(MIC = 0.078 mg/mL)and Escherichia coli(MIC = 5 mg/mL).Thus,Fr2 was the active components of Forsythia suspense leaves.Meanwhile research result showed that forsythiaside A was one of the main activity ingredients of Forsythia suspense leaves to play its inhibiting nitrosamine formation.At the same time,the results showed that forsythiaside A was one of the main active components in the Forsythia suspense leaves for inhibiting nitrosamine formation.2.The study on ethanol extraction of scutellaria was the same as above-mentioned.The results showed that the content of total polyphenol(53.11%)and total flavonoid(59.08%)of S4 was the highest among all the components.In addition,S4 has most capacities of DPPH· scavenging(IC50 = 3.72 ?g/mL),and nitrosamine formation inhibiting(IC50 = 1.06 mg/mL),what's more,it has strong antibacterial effect on staphylococcus aureus(MIC = 0.0625 mg/mL)and Escherichia coli(MIC = 0.25 mg/mL).Thus,S4 was the active components of scutellaria.HPLC analysis showed that the content of baicalein was the abounding(43.96%)in S4,which was one of the main active substances.3.Synergistic antioxidant and antibacterial activities of active components Fr2 and S4 were studied by Isobologram assay and checkerboard dilution method.The results showed that there was no significant difference between the complexes and the single component in the antioxidant and antibacterial activities.4.Taking into account the antioxidant and antibacterial activities of Fr2 and S4,in this experiment,Fr2: S4 = 1:3 was selected to study the preservation of sausage.The results showed that the complexe with different dosages(0.25%,0.5%,1%)had better preservation effect on sausages.When the sample addition amount was only 0.25%,the preservation effect of sausage was better than that of Vc-Na.Meanwhile it can effectively inhibit the p H value,POV value,TBA value,TVB-N value and the increase of nitrite content and thereby prolonging the shelf life of sausage. |
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