Study On Liquid Fermentation Process And Sensitization Of Artificial Bee Bread

Bee food,also known as bee bread,is rich in a large number of nutrients and bioactive ingredients in natural bee bread.Compared with pollen,bee bread is easier to absorb.Bee bread is gradually accepted by people as a health food.However,due to the difficulty of manual management and the serious damage to the original ecological environment of honey powder,bee bread often fails to meet the market demand.The allergenic proteins and antinutritive factors in pollen have great influence on the application range of pollen.Proteolysis in the fermentation process can destroy the protein epitopes of allergens or change their expression,so as to improve the immune activity of pollen protein.In this study,the dominant strains were isolated from the natural rapeseed bee bread and the effects of fermentation on the sensitization of bee bread were analyzed.Furthermore,a small liquid fermentation process(30L)was established and optimized.It provides an important theoretical basis for the production of high quality and low allergenic bee bread.The conclusions of this paper are as follows:(1)10 species of microorganisms were isolated from natural rapeseed bee bread,including 3 strains of Lactobacillus plantarum;Bacillus megaterium;Lactobacillus acidophilus;Lactobacillus garvieae;Aspergillus oryzae;Aspergillus versicolor;Rhodotorula;Lactobacillus rhamnosus.(2)The acid production and antibacterial activity of the identified 6 strains of lactic acid bacteria were determined and it was found that the acid production capacity of strain D was the strongest.All the six lactic acid bacteria showed inhibitory effects on escherichia coli and staphylococcus aureus,and bacteria A and C also showed inhibitory effects on bacillus subtilis.Bacteria C,D and G showed inhibitory effects on saccharomyces cerevisiae,while bacteria A,C,D and I had inhibitory effects on candida,while only bacteria D had certain inhibitory effects on aspergillus Niger,trichoderma and rhizopus.To sum up,bacteria D was selected as an excellent fermentation strain.(3)On the basis of single factor experiments,response surface model is established and analyzed the material liquid ratio,dosage of strains,stirring speed and fermentation temperature of the interaction between four factors and get the optimum strain fermentation conditions as follows: 25 % strains and solid-liquid ratio(m/v),quantity of lactic acid bacteria(v/v): 13%,stirring speed: 415 r/min,fermentation temperature:33℃.Under this parameter,the average activity of bee bread was 2.11×107cfu/g,and the average sensory score was 4.45.On the basis of response surface results,the optimal fermentation period was determined to be 4d with the number of live bacteria and sensory score of lactic acid bacteria as indicators.(4)In vitro and in vivo desensitization analysis of fermented bee bread by bacteria D showed that compared with pollen,the binding ability of allergen in fermented bee bread by bacteria D to Ig E in serum of patients was significantly reduced.In vivo assessment: recording the score of sensitization symptoms and observing the morphology of jejunum,it was preliminarily determined that the mice were in the allergic state and the sensitization of the artificial bee diet group was significantly decreased.Serum and cell levels showed that serum specific antibody Ig G,Ig G1 and IFN-γ stimulation factor in spleen cells were significantly higher than those in the pollen group,while serum specific Ig E,m MCP-1 and IL-4,IL-5 and IL-13 factors in spleen cells were lower than those in the pollen group.It can be seen that fermentation with bacterium D is an effective processing method to reduce the allergenicity of pollen.(5)The comparative analysis of the nutritional components of artificial bee bread,pollen and natural bee bread revealed that compared with pollen and natural bee bread,the contents of sugar and crude fat in artificial bee bread decreased significantly,and the contents of protein,amino acid,total flavonoids and the content of polyphenols increased significantly.These results indicated that the beneficial nutrients of pollen were not only not lost after probiotic fermentation,but also higher than those of natural bee bread.(6)It puts forward normative requirements on the production environment,quality requirements,specifications of raw and auxiliary materials,quality testing methods,storage conditions,and pre-packaging regulations for artificial bee bread products,and initially establishes artificial bee bread product standards.