Effect Of Cooking And Reheating Methods On The Quality Of Lentinus Edodes Soups And Prediction Of Shelf Life Of Lentinus Edodes Soups Products

Lentinus edodes(L.edodes),the world's second largest edible fungus,is an edible fungus,which is well-loved by people for its rich nutrition and delicious taste.What L.edodes is processed into L.edodes soups is a common cooking method of L.edodes during family-cooking.With rapid developing economy,fast-paced life has promoted the development of instant products.Therefore,the exploitation of convenient,delicious and nutritious L.edodes soups products will occupy certain market spaces.In this research,we studied that effect of cooking and reheating methods on the quality of L.edodes soups,and predicted the shelf life of L.edodes soups products.Main results were shown below:1.Effect of different cooking methods on the taste and non-volatile flavor components of L.edodes soups were detected using electronic tongue and HPLC.It was discovered that the content of soluble sugars,organic acids,taste nucleotides,free amino acids and equivalent umami concentration(EUC)value were the highest in L.edodes soups cooked by traditional atmospheric pressure cooking method(100?20 min).The content of soluble sugars and organic acids were lowest in L.edodes soups cooked by high temperature cooking method(120? 10 min).The content of taste nucleotides,free amino acids and the EUC value were lowest in L.edodes soups cooked by variable temperature cooking method(120? for 10 min,then 120?100?for 10 min).The intensity of umami in the L.edodes soups cooked by the traditional atmospheric pressure and variable temperature cooking methods were higher than L.edodes soups cooked by high temperature cooking method.The soups cooked by high temperature cooking method had higher the intensity of sourness and bitterness.The cooking methods had no significant effect on the rheological properties of L.edodes soups(P>0.05).2.Effect of different cooking methods on the aroma characteristic and volatile flavor compounds of L.edodes soups were analyzed by electronic nose and gas chromatography-mass spectrometry(GC-MS).The results indicated that the main volatile flavor compounds in L.edodes soups cooked in high temperature cooking method were 35 kinds,in variable temperature cooking method were 34 kinds,in traditional atmospheric pressure cooking method were 27 kinds.High temperature and variable temperature cooking methods helped the formation of volatile flavor compounds,while L.edodes soups cooked by traditional atmospheric pressure cooking method had the highest content of the L.edodes characteristic volatile flavor components(sulfur compounds)and aldehydes and ketones compounds.There was significantly different in the odor of the L.edodes soups cooked in three ways by electronic nose analysis(P<0.05).3.The time to reheat the L.edodes soups products in different ways was determined.The microwave(600 W)reheating time required 114 s;the steam(120?)reheating time required 450 s.Effect of reheating methods on the nutrients contents of L.edodes soups was analyzed.Results manifested that reheating methods had no significant influence on the content of soluble solids,ash and sodium in L.edodes soups(P>0.05).Contents of total sugar and reducing sugar were lower in the steam reheated L.edodes soups.Fat and protein contents were lower in the microwave reheated L.edodes soups.The taste and flavor characteristics of L.edodes soups were detected by electronic tongue,electronic nose and gas chromatographyion mobility spectrometry(GC-IMS).It was found that taste of L.edodes soups were similar among reheated L.edodes soups.The aroma characteristic of reheated L.edodes soups was significantly different(P<0.05).It was known from the GC-IMS results that the reheating method changed the content of volatile flavor substances in the L.edodes soups.Volatile flavor substances in microwave reheated L.edodes soups were more abundant than those of unreheated L.edodes soups and steam reheated L.edodes soups.4.While coliforms,aerobic plate count,color,pH and the lipid oxidation values(TBARs)were used as evaluation indicators,the accelerated shelf life test(ASLT)was carried out at constant temperature(40? and 50?)to study the quality change and to predict shelf life of L.edodes soups.Results indicated that the coliforms and aerobic plate count did not change significantly during storage(P<0.05),color changed significantly(P>0.05),the pH decreased,and the TBARs values increased with storage time.The correlation analysis showed that pH and TBARs values were key factors affecting the shelf life of L.edodes soups,and TBARs value had a greater impact.Based on the Q10 shelf life prediction model,we calculated the theoretical shelf life of L.edodes soups stored at 25? storage conditions was 226 d.