Research On Preparation And Embedding Technology Of Milk Flavoring Materials

Milk flavor has a great market value in the field of food additive development andresearch,and there were many researches on the preparation technology of dairy base but few reports on the research of embedding technology.This article mainly studied the effect of two-step enzymolysis method on the flavor of milk base material to prepare a baked flavored milky base material.Through complex coacervation,the gelatin-acacia gum was used as a wall material to embed the milky base material in order to obtain capsules and nanocapsules,and explored the changes of their characteristic aroma components before and after embedding.The main findings were as follows:(1)The sensory evaluation and acid value were used as indicators to explore the effect of different supplemental substrates and the amount of enzyme added on the aroma produced by the dairy base.The results showed that whey powder 1 was the best co-substrate,the optimum amount was 12.5% of butter quality,and the optimal addition amount of vanillin was 0.75% of butter quality.The optimum addition amount of lipase A was 0.75% of butter mass,0.2% of the mass of butter oil,and 5 hours of enzyme hydrolysis time.The optimum amount of protease B was 0.03% of butter mass and the hydrolysis time was 8 hours.Under this condition,the aroma was the most intense and pure,with a strong roasted flavor.(2)Using particle size(DLS)and morphological distribution observed under an optical microscope as indicators,explored the impact of core/wall ratio,emulsification rate and other factors on the embedding effect of micro-capsules for milky base materials,and optimized the process using the response to its preparation process.The results showed that the p H was 4.20,the ratio of core to wall was 1:1,the homogenization speed was 13000 rpm,the re-polymerization temperature was 40°C,and the re-polymerization time was 40 min.Under these conditions,microcapsules with a high sphericity of 140 ?m and uniform size were obtained.(3)Using DLS(particle size),PDI(polydispersity index)and Zeta(potential)as indexes,the influence of p H value,emulsifier addition amount and other factors on the embedding effect of nano-capsules of milk-based nano-capsules was investigated.And in response to its preparation process for optimization,the results showed that: p H 4.85,the core wall ratio of 1:3,emulsifier addition amount of 0.4%,homogenization speed of 13000 rpm,stirring speed of 300 rpm.The average particle size of the milk flavored nanocapsulesprepared under this test condition was 108.99 nm,the PDI was 0.221,and the potential was-29.87 m V.(4)The GC-MS and electronic nose technology were used to compare and analyze the changes of the characteristic aroma components of the milk base before and after embedding.The simultaneous distillation and extraction(SDE)and solid phase microextraction(SPME)were investigated.Volatile component extraction effect.The results showed that the best extraction condition of SDE method was that dichloromethane used as the extractant and the extraction time 2h.The optimum extraction conditions of SPME method were 75?m extraction fiber,extraction temperature 55°C,extraction time50 min.(5)The embedding effect was evaluated with the representative aroma component vanillin,the difference between vanillin before and after embedding was very significant,and the nature of nanocapsules was more stable.The electronic nose could obviously separate the samples before and after embedding,and the aroma released by the capsule when heated at 100°C was closer to the aroma of the non-embedded cream base.