Studys Of The Protein Extract And Utilization Of Producing Protein Feed From Tea Residues

The main content of this paper is divided into tow parts:First, low-concentration alkali solution was adopted to extract the protein of tea residues, the best extraction condition was obtained after study, and then, precipitation and decoloration which were two parts of purification were researched preliminary, the best condition was obtained after study; Second, microbial solid fermentation was adopted to ferment tea residues into protein forage, the best fermentation condition was obtained after study.The main content and results as follows:(1) Low-concentration alkali solution was adopted to extract the protein of tea residues, the extraction condition was researched by single factor experiment and orthogonal design experiment, the best extraction condition was:pH 12,90℃(extraction temperature),50:1 (water to solid ration),60min(extraction time),the extraction rate of protein was about 29.71%. The precipitation and decoloration condition was researched after extraction. Three different methods such as isoelectric point precipitation,ammonium sulfate precipitation,IE-ammonium sulfate precipitation were researched respectively, the result was:the isoelectric point of tea protein extract was 5, the precipitation rate of protein was about 37.05% by the method of isoelectric point; The precipitation rate of tea protein was about 82.88% by ammonium sulfate precipitation, and the concentration of ammonium sulfate was 80%; The best precipitation method was IE- ammonium sulfate precipitation, the conditions were:pH5,80% ammonium sulfate concentration, the precipitation rate of tea protein was about 82.88%. Four different materials of decolorizer (granular active carbon,powder active carbon,diatomite,acetone)were used to decolor the crude protein of tea residues, The best decoloring conditions were researched by single factor experiment and orthogonal design experiment:the dosage of power active carbon was 1.5%,50℃(decoloring temperature),60min(decoloring time), the yield of tea protein was88.53%, and the tea crude protein was yellow grey;(2) The method which was adopted to ferment tea residues into protein forage was microbial solid fermentation. Three different of inorganic nitrogen source(carbamide,ammonium sulfate,potassium nitrate) were researched, The best selection and dosage of inorganic nitrogen source on the solid state fermentation was carbamide and the dosage was 2%; Three different methods of (Aspergillus niger Single strains fermentation saccharomycetes Single strains fermentation and mixed strains) were researched, fermentation condition was:the dosage of strain was 10% into 20g tea residues culture medium,40% water,29℃,the dosage of carbamide was 2%,5 days, the result showed that:mixed strains was better than other methods, and the best selection was mixed strains. Different proportioning ration of mixed strains were researched respectively, and the best proportioning ration was 1:3 (Aspergillus niger dosage to saccharomycetes dosage, v/v). Four main factors (the dosage of strains,fermentation temperature,the dosage of water,fermentation time) were researched by single factor experiment and orthogonal design experiment, the result showed that:the best fermentation condition was 1:3(Aspergillus niger dosage to Saccharomycetes dosage),the dosage of strains was 12%,the dosage of carbamide was 2%,28,40% water,7days, the protein content of fermentation products was 29.84%, the protein content increased 11.28% compared with control, the fermentation effect was remarkable.