Study On The Determination Of Flavor Substances And Preparation Technology

Twelve kinds of edible fungi was studied, including Grifolafrondosa, Agrocybe cylindracea, Tricholomataceae, Hericiumerinaceus, Tricholoma matsutake, Agaricus blazei Murrill, Cantharelluscibarius, Cordyceps militaris, Boletus edulis, Pleurotus eryngii, Coprinuscomatus and Lentinus edodes. This thesis main focused on the study ofvolatile compounds and nonvolatile taste components using differenttechniques. Based on the result Lentinus edodes and Agaricus blazeiwas selected as the next material, a preliminary study was carried outabout the preparation process of taste components. These findingsprovided an important scientific basic for us to better develop and usethe food value of edible fungi.The main results were as follows:1) Compared the smell components of Lentinus edodes by steamdistillation, simultaneous distillation and extraction, supercritical fluidextraction and solid phase micro-extraction method. According to thedetection of sulfur compounds and eight-carbo compoundsHeadspace solid-phase microextraction was suitable for the rapidextraction and steam distilation for large fabricated.2) Headspace solid-phase microextraction combined with gaschromatography-mass spectrometry(HS-SPME-GC-MS) was used toidentify the volatile flavor compounds of other species. Results suggestthat the main components of each type of mushroom aroma wererequired.The flavor components of edible fungi are very complex, notsimply a compound contribute to, but a variety of compounds.3) Electronic nose technology was used to assist analysis thearoma components. Experimental results show that:the fingerprint ofedible fungis is characterized by P10/1, P10/2, P40/1, TA40/1, TA/2sensorresponse values were higer(0.4-0.6), and LY2/G, LY2/AA, LY2/GH,LY2/gCT sensors respones values were negative. However, it is significantly different from the trends of other aroma such as tea, beef,wine and cheese. Principal component analysis and discriminant factoranalysis can well distinguish the different edible mushroom aroma.4) Nonvolatile taste components in twelve kinds of edible fungi,including water-soluble sugar, free amino, taste nucleotide and organicacid, were analyzed. The main water-soluble sugar in edible fungi weremannitol and trehalose, displayed by high performance anionchromatography-pulsed amperometric detection. And the significantcomposition effecting the taste of edible fungi was umami and sweettaste amino, indicated by automatic amino acid analyzer. AHPLC-based method for determination of six kinds of taste nucleotidewas set up. Optimal separation was achieved by loading10μ L sampleson to an Ultimate AQ-C18column(250mm×4.6mm,5μ m), and thenusing a flow rate of1.0mL/min at30℃eluting with KH2PO4buffer(pH4.68). The samples were scanned from200nm to400nm and monitoredat259nm. Using the method, twelve kinds of taste nucleotide wereanalyzed and5’-guanine nucleotide was main nucleotide of the flavorof edible fungus. Even more, a HPLC-based method for determinationof organic acid was also described. Optimal separation was achievedby loading10μ L samples on to an Ultimate AQ-C18column(250mm×4.6mm,5μ m), and then using a flow rate of1.0mL/min at30℃elutingwith KH2PO4buffer(pH2.8). The samples were scanned from200nm to400nm and monitored at210nm. The results showed significantdifference in content of different organic acid types in different ediblefungi.5) In this study, as raw materials of suitable for the development ofumami taste five matirials including Agaricus blazei Murrill, Coprinuscomatus, Agrocybe cylindracea, Tricholoma matsutake and Lentinusedodes were filtered by calculating the EUC value, which was88.27,86.82,45.38,31.93and20.67. Better ultrasonic process conditions for the ultrasonic time was30min and the ultrasonic power is400W. Theenzymatic hydrolysis process of flavourzyme and papain for Lentinusedodes was studied with the content of α-amino nitrogen as marker bymeans of single factor experiment and orthogonal tests. The resultsshowed that optimal hydrolysis conditions were that flavourzyme,papain, time and temperature are0.25%,0.50%,6h,50or60℃.6) The contents of flavor nucleotides, free soluble and free aminoacid in fresh Lentinus edodes and Agaricus blazei Murrill dried bydifferent drying methods (hot air, natural air, vacuum, vacuum freeze)were investigated by various methods.Results showed that dry goods byvacuum drying with a rich mushroom flavor and contain high levelflavor nucleotides, free soluble and free amino acid. Thus, using thevacuum drying method make better use of species development, butdue to poor rehydration performance can not be edible as dry goodsbubble.