Research On Preservation Technology Of Tricholoma Matsutake In Changbai Mountain

Tricholoma matsutake is a kind of respiratory climacteric mushroom,which is prone to open umbrellas and browning after harvest.How to develop reasonable and effective measures to preserve Tricholoma matsutake is the key to determine the edible quality and commercial value of Tricholoma matsutake after harvest.In order to study the preservation technology of Tricholoma matsutake in Changbai Mountain and extend its shelf life,the experiment of preservation of Tricholoma matsutake was carried out with low temperature,air conditioning and composite packaging film respectively.The evaluation model of preservation technology of Tricholoma matsutake in Changbai Mountain was established with the indexes of respiratory intensity,weight-loss rate,total soluble sugar,Browning rate,polyphenol oxidase activity,cell membrane permeability and sensory quality.The experimental results of low temperature storage and controlled atmosphere storage show that temperature,humidity and gas ratio can directly affect the respiration and transpiration of Tricholoma matsutake after harvest.The best storage temperature is 2?4?,the best storage relative humidity is 85%?90%,the best controlled atmosphere ratio is V(O2):V(CO2):V(N2)=3:15:82,and the shelf life can be extended for 7 days.In the experiment of low temperature storage,it was found that there were sunken browning spots on the stalk and canopy of Tricholoma matsutake at the 12th hour of storage under the condition of 1?,so it was concluded that the critical temperature of Tricholoma matsutake cold damage was 1?,and there was no injury of low oxygen and high carbon dioxide in each treatment group in the experiment of controlled atmosphere storage.In order to reserch the packaging film preservation material suitable for matsutake of changbai mountain,burdock extract was selected as the modified material and gelatin was used as the substrate to prepare the composite film.The results of the experiment showed that the burdock extract stored at 4? had better bacteriostasis than room temperature,the bacteriostasis of the burdock extract was not affected by temperature,the hydroxyl radical scavenging rate and superoxide anion scavenging rate were not affected by temperature,and the burdock extract could be stored for up to 4 days.Through chicken skin and rabbit skin gelatin film were prepared to study the preparation of composite membrane materials with different properties,determination of physical properties of each composite membrane and structure characterization,found in the skin for material preparation of gelatin composite membrane burdock extract optimal concentration of 5%,the ratio of the composite membrane water vapor transmittance under 1.91g(m·s·Pa)-1·10-8,the tensile strength is 33.1 MPa,hydroxyl free radical clearance rate is 59.98%;The optimal concentration of burdock extract was 6%when the gelatin composite film was prepared from rabbit skin,and the water vapor permeability of the composite film was 2.43g(m·s·Pa)-1·10-8,the tensile strength is 64.32Mpa,and the hydroxyl radical scavenging rate is 63.43%.Through according to the results of infrared spectrum analysis of composite membrane with the increase of concentration of burdock extract,amide I gradual migration,it also suggests that happened after the burdock extract and gelatin blending of polymerization,the formation of hydrogen bonds to enhance the overall performance of composite membrane.Amide I belt is three helical structure of collagen protein secondary structure,through the study of characterization results,amide I belt can be further analysis of burdock extract impact on the secondary structure of the composite film.The composite membrane with different burdock extract concentration in 1700-1600cm-1.The results of spectral band fitting showed that with the increase of burdock extract concentration,a-helix and irregular curl decreased gradually,?-fold and ?-turn increased gradually,which indicated that the secondary structure of composite gelatin film changed to ?-fold and ?-turn due to the addition of burdock extract,which indicated that the addition of burdock extract made the molecular chain of gelatin polypeptide expand and expand,and gelatin It polymerizes with phenols,ketones and related groups in burdock extract,which reduces the hydrophilicity of gelatin and weakens the polymerization between gelatin peptide chains.The composite membrane was observed by SEM electron microscope.When the concentration of arctium lappa extract was within the experimental range,no phase separation appeared on the surface of the two composite membranes,indicating that there was a good compatibility between gelatin and arctium lappa extract.When the concentration of burdock extract gradually increased to the optimal ratio,the white crystals produced by the polymerization of burdock extract and gelatin were significantly increased,while the white crystals were decreased when the concentration of burdock extract exceeded the optimal ratio.The experimental results showed that the respiratory intensity,weight loss rate,total soluble sugar,browning rate,polyphenol oxidase activity,cell membrane permeability and sensory quality of Tricholoma matsutake kept fresh by different packaging films were studied.It was found that the good performance of burdock chicken skin gelatin film and burdock rabbit skin gelatin film in water vapor permeability,antibacterial and antioxidant capacity,The fresh-keeping effects of different packaging films on Tricholoma matsutake were as follows:Burdock rabbit skin gelatin film>burdock chicken skin gelatin film>polyethylene film.Through the establishment of a comprehensive evaluation model for the preservation technology of Tricholoma matsutake in Changbai Mountain,it is found that the comprehensive score of using burdock extract/rabbit skin gelatin composite film for the preservation of Tricholoma matsutake is the highest,which is 0.739,followed by air-conditioned preservation,which is 0.535,and finally low-temperature storage,which is 0.478.In practice,the comprehensive use of various methods can be considered,and the comprehensive score can be used as the basis of the method selection sequence.