| The mushrooms have been used since earliest times not just only as food items or food flavoring materials,but also for medicinal and functional purposes throughout the world,especially in China.The production of many the mushroom edible products in the industries lead to quality deterioration,such as browning and moisture loss,caused due to the changes in enzymatic activity.Consumer demand has blown up for the processed products that can preserve their maximum original characteristics.The Shiitake(Lentinula edodes)is an edible mushroom that has been cultivated for centuries in the Asian countries like China,Korea,Japan,Singapore,and Thailand.The Shiitake mushrooms grow naturally on decaying wood of hardwood trees and have traditionally been grown on short lengths of freshly-cut logs.The mushrooms are richer in water content,but after reaping,the higher ratio of water is lost because of the fact that there is no fence to defend them from evaporation of water.The mushrooms have short and limited shelf-life,about fewer days,therefore it becomes necessary to preserve them for future use and get maximum income from it.This dissertation concentrates on the following four areasIn the first part of the study was carried out to develop and formulate a value added product in the form of pickle incorporated with and without mustard oil.Shiitake mushroom used to prepare two pickled and were evaluated for their physicochemical properties,antioxidant capacity and sensory characteristics.The two pickled were termed as mustard oil MOVS,without mustard oil,vinegar and salt SWVS.Pickled formulated with MOVS was found to be excellent in color,flavor,texture,taste and overall acceptability as compared to pickled formulated with SWVS.The pickle formulated with MOVS showed highest score 5.7 for overall acceptability of pickle no significant difference(P>0.05)was obtained between the texture and overall acceptability.The antioxidant activity MOVS and SWVS pickles demonstrated a significant result in scavenging free radicals except for DDPH.However results indicated that they have good antioxidant activity.The p H of the both types of pickles decreased significantly(p<0.05).However,HPLC analysis of both pickles revealed organic acids during the fermentation in the MOVS malic acid at 4.354,lactic acid at 5.069,citric acid at 5.489 and succinic acid at 7.301 at the retention time of 4.2,4.3,4.5 and 6.8 minutes respectively.Whereasthe SWVS pickle showed the peak for three acids present in the pickle sample,where the first peak indicates malic acid at 4.303 with the retention time of 4.2 min,the second peak indicates acetic acid at 6.573 with the retention time of 6.2 min,and the final peak was found of succinic acid at 7.304 with the retention time of 6.8 min.Further study of pickles products during storage conditions is required.In the second portion of this dissertation,the Lactobacillus L.casei,Lactic culture BB-46,and Vegetable starter culture 60 were used as a starter culture on the quality of Shiitake mushroom pickle.The aim of this study was to determine the effects of starters cultures(LAB)on the nitrite and organic acid content of the pickled mushroom.The population of LAB in the three kinds of starter's products was over 107 logs CFU/m L throughout the fermentation process.During fermentation,nitrite content decreased until15 thday and remained unchanged thereafter.Whereas,no apparent nitrite peak was observed for the pickle inoculated with L.casei,BB-46,and vegetable starter culture 60,while only small fluctuations in nitrite concentration were observed for pickle inoculated with starter cultures of L.casei.Furthermore,it was observed pickled sample contained three acids.The first peak at 9.368 indicates malic acid with the retention time of 10 min,the second peak at 11.671 indicates lactic acid with the retention time of 12 min and the final peak was found of citric acid at 12.605 with the retention time of 13 min.Our results thus suggest that L.casei should be used as a starter culture in the production of fermented pickled mushrooms.The third area of this dissertation to determine a better method to process the fruiting body of Shiitake mushroom for pickles product and were investigated for the changes in the volatile composition,texture analysis,organic acid,5'-nucleotides compound using solid phase micro extraction combined with gas chromatography-mass spectrometry and an electronic nose.In this study pickled prepared with different lactobacillus strains the volatile composition of freeze dried pickled was analyzed by SPME,GC-MS.Results identified and quantified in control pickle,including 2 sulfur compounds namely 1,2,4-Trithiolane and Lenthionine,Whereas in lactic culture L.casei pickled sample only detected one sulfur compound Lenthionine and further in lactic culture BB-46 sample detected 4 sulfur compounds 1,2,4-Trithiolane,1,2,4,5-Tetrathiane,Lenthionine and 1,2,3,4,5,6 Pentathiepane respectively.Results of texture analysis of pickled samples decreased during fermentation in the range of 203.27±36.52(Table-1).5'-nucleotides were observed in the pickled including GMP,CMP and UMP.While 5'-GMP contain only two pickles but did not contain in BB-46 and L.casei sample30.86mg/m L,29.88 mg/m L respectively(Table-2).Antioxidant activity demonstrated a significant result in DDPH except in ABTS and reducing power.Furthermore the three acids were found in the L.casei sample malic acid,citric acid and acetic acid as compared to BB-46 sample.The fourth part of this dissertation covered a study on crude water-soluble polysaccharides.Three different mushrooms were used in this study for comparison including Shiitake(Lentinus edodus),Auricularia auricula,and Poria cocos were termed as AAP,LDP,and PCP,respectively.Results of the “Fourier Transform-Infrared(FTIR)showed that the three crude polysaccharides were all composed of ?-glycoside linkages3304-1000cm-1,and continued until 658-1000 cm.-1.FTIR analyses suggest that there were no significant differences among chemical compositions of crude polysaccharides isolated.Further three fractions were analyzed for monosaccharide compositions it was observed that AAP and LDP were consist of L-rhamnose,D-galactose,D-glucose,arabinose and D-mannose whereas the PCP was found to consist of D-mannose,Dgalactose,and D-galactose.However,the antioxidant activity of AAP demonstrated a significant result in scavenging free radicals than PCP. |
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