Study On Extraction Of Agaricus Bisporus Flavor Enhancer

Agaricus bisporus is very rich in flavor amino acids and nucleotides, such asglutamic acid, aspartic acid and inosine monophosphate, guanosine monophosphateand cytidine, all of which have strong fresh effect on foods. These flavor ingredientscan be used as a natural flavor enhancer source applied to the food industry, especiallyin the condiment industry.In this study, A. bisporus was used to extract flavor enhancer as raw materials.This research studied extraction of bisporus flavor enhancer from fruit bodies andmycelia of A. bisporus respectively. The main contents and results of the study were asfollows:1. Study on flavor agent extraction from fruit bodies of A. bisporusHydrolyzed A. bisporus by adding different kinds of enzyme. Firstly, chose theappropriate protease used in the hydrolysis;then studied the adding method of cellulase;the factors affecting the proteolytic effect were discussed, and then designedorthogonal test to determine the optimal process of enzyme hydrolysis.5’-phosphodiesterase hydrolysis conditions were also explored to determine theoptimum hydrolysis conditions as proteolytic experiment.Results: Neutral protease was chosen as the proteolytic enzyme;added thecellulose to enzymatic hydrolysis first, then determined the hydrolysis process. Theoptimum technical conditions were: adding cellulase first, solid to water ratio was1:20,amount of enzyme250U/g, pH6.0, temperature55℃to hydrolyze120min, thenadding neutral protease enzyme, amount of enzyme1500U/g, temperature45℃, pH6.5to hydrolyze150min. After hydrolyzed by these two enzymes, the content of α-aminonitrogen was36.96mg/g.And then the5’-phosphodiesterase enzymatic hydrolysis experiment was carriedon, the best technology was determined as this: the amount of enzyme600U/g, pH7.0, hydrolysis temperature70℃, hydrolysis time was150min, the content of5’-nucleotidase was9.43mg/g.2. Study on decolouration of the A. bisporus hydrolyzateThe decolorization process of activated carbon of hydrolyzate was studied. Theoptimum decolorization process was determined by single factor experiments andorthogonal test. Results of the study: activated carbon2.0%, pH5.0, bleaching temperature50℃,bleaching time40min. Under these conditions, the decolorization of the hydrolyzatewas85.66%, α-amino nitrogen loss rate was8.24%.3. Submerged fermentation process of A. bisporus（1） Studied the influence of medium mycelium through the bisporus liquidfermentation process on biomass. Carbon, nitrogen, trace elements and growth factorswere studied to determine the optimal fermentation medium by orthogonal test.Experiment results: the optimum carbon source was glucose, nitrogen source wassoybean meal. The best formula of the fermentation medium was glucose2.5%,soybean meal0.8%, KH₂PO₄0.2%, MgSO₄0.08%, V_B10.001%.（2） To optimize the fermentation conditions of bisporus, including the thefermented initial pH, and culture temperature conditions, rotation speed, thefermentation time. Determined the optimum fermentation process by orthogonal test.The results of experiment showed that: the optimum fermentation conditions were:10%of the inoculum size, initial pH7.5, the liquid volume100mL, incubationtemperature24℃, the rotation speed100r/min, incubation time7d. Under theseconditions, the mycelia biomass reached9.19g/L.4. Flavor enhancer extraction from Bisporus myceliumCollected the fermentation mycelium, dried them under80℃,then grinded,hydrolyzed these mycelium by enzyme with method like hydrolyzing the fruit bodiesof A. bisporus. Determined the optimal hydrolysis process.Results of experiments: solid to water ratio was1:15, added cellulase first, amount ofenzyme200U/g, pH6.0, temperature60℃to hydrolyze for120min,then added neutralprotease enzyme, amount of enzyme1000U/g, pH7.0, temperature55℃to hydrolyzefor150min. After hydrolyzed by these two enzymes, the content of α-amino nitrogenwas29.72mg/g.Optimum process of5’-phosphodiesterase hydrolysis: the amount of enzyme500U/g, pH7.0, reaction temperature70℃, the hydrolysis time was150min. After beenhydrolyzed, the content of5’-nucleotidase reached11.21mg/g.