Optimization Of Explosion Puffing Drying Process For Pleurotus Geesteranus At Variable Temperature And Pressure Difference And Analyze Of Taste Components And Volatile Components

Pleurotus geesteranus is famous for its beautiful shape,rich nutrition,taste,and rarity.However,due to its storage instability and increasing output by year,an improved way of processing is necessary to expand the producing industry.Hence this experiment uses the response surface method for the technology of explosion puffing drying at variable temperature and pressure difference of Pleurotus geesteranus was optimized and analyzed the aroma components before and after puffing.In the first part,the production process of Pleurotus geesteranus was generally determined utilizing single-factor experiment.The response surface methodology was used to optimize the three conditions of pre-drying time,vacuum temperature and vacuum time,which has established by measuring the color difference value,moisture content,hardness,and crispness as four indicator control.A quadratic regression equation was then established in order to determine the optimal processing requirement.The second part uses high performance liquid chromatography,amino acid analyzer,and electronic tongue to measure taste components analysis of Pleurotus geesteranus before and after explosion puffing drying at variable temperature and pressure difference;headspace solid-phase microextraction(HP-SPME)and gas chromatography-mass spectrometry(GC-MS)methods are then used to analyze the aroma components of Pleurotus geesteranus before and after puffing.The results are shown below:1.It was determined that the length of Pleurotus geesteranus 8cm,pre-drying time 3.8h,vacuum temperature 70℃,and vacuum time 2h were determined by experiments.The hardness of the Pleurotus geesteranus chips was 2098±42.65 g,and the crispness was 10±1.84 pieces.The moisture content was 4.83±0.15%,and the color value was 19.1±0.4,which was close to the predicted value.The appearance,taste,and quality were all very good.2.Taste nucleotides and taste amino acids are extruded maximum 1.68mg/g,19.171mg/g,respectively,reached the flavor of amino acids content is much greater than the 5’-nucleotide content,The total number of flavor amino acids and flavor nucleotides rose first and then decreased.With fresh samples as reference,the salty and umami values of the pretreated samples increased,the bitterness values of the astringent tastes did not change significantly,and the acidity values decreased.3.The aroma components of Pleurotus geesteranus were mainly alcohols,and the amount of alcohols after processing was reduced.The relative content of the alcoholic substances in the pre-treated Pleurotus geesteranus was reduced from 75.51% to 5.15%,and then decreased to zero after puffing.The 1-octen-3-ol with a characteristic aroma gradually decreases to zero as the processing proceeds.After temperature-expanding differential pressure expansion and drying,the variety of aroma components was 19 species of fresh oyster mushroom,16 species after pre-drying with hot air,and 15 species with variable temperature and pressure difference after expansion and drying.There are 11 kinds of 15 components disappeared after the hot air pre-drying treatment and the variable temperature differential pressure expansion and drying treatment.The special flavoring substances generated after expanding are: heptaldehyde,p-isopropyl-benzaldehyde,2-Heptone,2-phenylcrotonaldehyde,2,3-octanedione,methylmercapto ketone,isovaleric acid,dipentene,p-xylene,o-dichlorobenzene.