Study On Technology Of Extracting Nucleotide From Edible Fungi And Exploitation Seasoning Products

Edible fungus is nutritious, delicious and its unique flavor (including the smell and taste).The nucleic acid is rich in it, and its nucleic acid mainly is RNA, which is hydrolyzed into umami5’-nucleotide easily. Mushroom is rich in resources, the use of its flavor compounds to develop natural seasonings is an important direction of deep processing in edible fungi.This paper has studied on the methods of nucleic acid extraction, conditions of hydrolyzing nucleic acid into nucleotide and high performance liquid chromatography for determining nucleotide.Also, this text has studied the conditions of separation and purification nucleotide, and preparation method of mushroom sauce as using mushroom picked scraps for the basic materials preliminarily. Major tests and results are as follows:Firstly, chose Agaricus bisporus as material and use phosphorus method to determine the total nucleic acid content, has compared the enzymatic, heat reflux, ultrasonic and microwave method to extract nucleic acid. The results showed that the microwave method is superior to other methods, so chose microwave method for extracting nucleic acid. By doing single factor (time, power, salt concentration, pH value) experiments and orthogonal test, we’ve got the best extraction conditions:30min,300w,4%aCl, pH value of11. Measured the nucleic acid content of Agaricus bisporus, Flammulina, the shiitake and handle cover of Mushrooms were2.78%,2.96%,2.50%nd1.67%, respectively.Secondly, a method for determination of nucleotides in Agaricus bisporus by HPLC is reported. Ultraviolete detector,260nm wavelength Eclipse XDB-C18column was used, with column temperature was25℃. Mobile phase:water:methyl alcohol:acetic acid: tetrabutylammonium hydroxide=894.5:100:5:0.5. The speed of mobile phase was1.0mL/min. The relative coefficient of four nucleotides were all higher than0.999.Using phosphodiesterase to hydrolyse agaricus bisporus nucleic acid. To obtain the optimum processing condition for enzymetic nucleic acid, with substrate concentration was2mg/mL, preliminarily studied its hydrolysis conditions:time, temperature, pH and enzyme concentration by single factor experiment. The results showed that the conditions: time of3h, temperature of40℃, pH of5.8and enzyme/substrate of1300U/g were better than others, the hydrolysis rate of nucleic acid is68.1%.The effect of10different ion-exchange resins adsorption and separation of edible nucleotide hydrolysis were screened by static adsorption and desorption test. The overall nucleotide adsorption and desorption rates of D201GF are all higher than others.Through t using D201GF ion-exchange resin dynamic adsorption and desorption nucleotide tests showed that under the conditions of pH10.0nucleotide has better dynamic performance, flammulina nucleotide-like solution on the amount of resin size and the best ratio was8:1(mL nucleotide solution/g wet resin); using0.6mol/L HCl lution is best, elution rate can be achieved80.3percent. Through D201GF adsorption resin adsorption and elution, the nucleotide concentration could be increased by5-6times.At last, has researched on using edible fungi scraps to develop innovative seasoning products.Examined the process of using edible fungi scraps to develop umami seasonings. Extracted edible fungi scraps by microwave, then used papain and5’-phosphodiestera se enzyme to hydrolyze its protein and nucleic acids. Cmpared the amino acid and nucleotide levels before and after enzymatic hydrolysis, showed that, after hydrolysis flavor amino acids and nucleotides all increased significantly, up to four times at most. Then concentrated and dried, grinded the three kinds edible fungi hydrolyzate.Based on flavor amino acids, nucleotides and salt interact with each other for fresh principle, put the three kinds edible fungi hydrolyzate powder separately with different proportions of salt, monosodium glutamate,tasted by the staff to determine the formula, got the edible fungi seasoning base material.Studied the process and formulations of using edible fungi scraps hydrolyzate to prepare Maillard reaction meat seasoning. By single factor experiments to determine a better reaction formula for Maillard reaction:glucose consumption was4.0%,xylose consumption was2.0%, glycine0.3%osage, dosage of0.3%lanine,cysteine dosage of1.0%, thiamine hydrochloride dosage was0.5%. Through the single-factor experiments and orthogonal test for Maillard reaction conditions, obtained the optimum reaction conditions were:temperature of120℃, time of70min, pH6.0. Used GC-MS to analysis the volatile components of meat seasonings, obtained the main flavor compounds included furans, thiazoles, carboxylic acids, heterocyclic, sulfur, and some other flavor of meat as the aldehyde class, ketones, esters and alcohols and other compounds. Using hydrolyzate of edible scraps could be obtained realistic style meat seasoning.