| Jerusalem artichoke is composite helianthus perennial herb,which be commonly called as Jerusalem artichoke,it have good nutrition and health protection function,which contain abundant nutriments,such as Inulin,fructooligosaccharides,amino acid and vitamin.In recent years,used the modern separation technology,inulin,fructooligosaccharides and ultra-high fructose syrup were produced from Jerusalem Artichoke tuber which has recognized its high nutritional value and health effects in the internation.Jerusalem artichoke wine has widely development foreground because of it's nutrition component.In this paper,slected fresh Jerusalem Artichoke as material, after Helianthus analysis of the Jerusalem Artichoke tuber's fine fraction,take the inulin as the main carbon source in liquid inulin fermentation,obtaining the inulinase exonuclease through this test.Then using inulinase exonuclease acting on the Jerusalem artichoke extract to preparate the sugar liquid;used Response Surface Optimization of Aspergillus niger inulinase fermentation conditions for the fermentation process.Specific studies content and result were as follows:(1) Inulase can catalyze levan of Jerusalem artichoke hydrolyze as fructose or fructooligosaccharides.25 strains capable of producing inulinase were isolated from rhizosphere soil of Jerusalem artichoke.Of all,three strains with high inulinase productivity were obtained. Selecting the bacterium A18(its inulinase productivity is 14.5U/ml) to further screening.Observed and identified by bacterium morphological and microscopic,A18(Aspergilhts niger 18)was dentified as Aspergillus niger.(2) By single factor test,the optimum carbon source:Jerusalem artichoke powder(consider the cost,in this papar,used the extract of Jerusalem artichoke as carbon source),the optimum nitrogen source were peptone and NH4H2PO4.After studying on its fermentation condition,the optimum condition for higher inulinase production by Aspergillus niger A 18 was determined as shown below:extract of Jerusalem artichoke 7.0%,peptone 0.60%,0.5%NH4 H2PO4,pH5.5,inoculated with 1.0-2.0ml of spore suspensions(2.5×106CFU/mL ).Maximal inulinase activity of A 18 obtained after 96 h of growth in shake cultures(50 mL of medium in 250 mL flasks),temperature is 28-30℃. agitation speed 240 r / min are optimumconditions for A18.(3) Used RSM analytical method,eight factors twelve tests were designed by Plackett-Burman, significant factors of Aspergillus niger A18 inulinase production were the Jerusalem artichoke extract,peptone,(NH4) H2PO4.used Box-Behnken RSM analytical method to get a regression equation:Y1=33.1+0.7875*X1+0.2875*X2+1.425*X3-3.475*X1*X1-0.1*X1*X2+ 1.625*X1*X3-0.025*X2*X2-0.925*X2*X3-4.5*X3*X3。the best fermentation conditions of the hightest activity which aspergillus nigerA 18,produced the result as follows:Jerusalem artichoke extract7.8%, peptone 0.65%,(NH4) H2PO4 0.55%,initial pH5.5,shake flask speed160r / min,28℃culture for 4 days.The hightest enzyme activity reached 34.6U/mL,and increased nearly 50%than optimizing the pre-activity.(4) Studied on the enzymology properties of inulinase by the above-mentioned culture liquid that Optimization culture medium fermentated,the result of the best Optimization inulinase hydrolysis as follows:temperature 55-60℃,concentration of substrate 12%,the amount of enzyme 9U / g,enzyme hydrolysis time 10h,enzyme hydrolysis rate of 89%.(5) Studied on the Saccharomyces cerevisiae Hansen,some factors that affect the properties of Jerusalem artichoke alcohol fermentation were studied,such as initial pH,temperature, concentration of initial sugar,inoculate measure,the result of the fermentation condition as follows:pH4-5,temperature 22℃,concentration of initial sugar 18.8%,inoculate measure 0.1%. And different concentrations of Jerusalem artichoke extract fermentation experiments were carried out.(6) The result of alcoholic fermentation RSM test showed to get a regression equation: Y2=9.641111+0.375101X1+0.379761X2+0.786481X3-0.422529X1X1 0.1X1X2+0.15X1X3-0.316463X2X2+0.05X2X3-0.457884X3X3 slected the exact of Jerusalem Artichoke as material,enzyme hydrolyzed by Inulase,the Optimization fermentation conditions that Saccharomyces cerevisiae Hansen produced ethanol as followed:Temperature 22℃,pH 5.0,sugar degree of fermentation liquid 18.8%,speed of fermentation moderate,the conversion rate of alcohol was highest,the content of ethanol in the fermention processing reached 9.98%after fermentating six days.At the same time,this paper mensurated the alcohol level,the reducing sugar,total sugar,pH,soluble solids,total acid in the Jerusalem artichoke wine.result to determine which alcoholicity is 10.63 ml/100mL,total sugar-content 0.82g/100mL,acid-content is 0.8g/100mL,solubility- content is 3.5g/100mL.(7) The aroma components of Jerusalem artichokes wine were isolated and identified by capillary GC-MS method,68compounds were identified in the sample,including 21 alcohols,15 acid,12 esters,7 ketones,2 hydroxybenzene,3 hydrocarbons,8 other aroma component. |
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