糧油加工工藝學(xué) 課件 Chapter 6 淀粉加工

第六章

淀粉加工Chapter6Starchprocessing第五章

淀粉加工Chapter5Starchprocessing教學(xué)要求：知識(shí)要求：1.掌握淀粉生產(chǎn)的基本工藝流程；2.了解淀粉的性質(zhì)；3.掌握淀粉制糖工藝。能力要求：1.具備實(shí)際生產(chǎn)淀粉的能力；2.根據(jù)淀粉的性質(zhì)，開發(fā)相應(yīng)的產(chǎn)品。素質(zhì)要求：1.培養(yǎng)創(chuàng)新精神，嚴(yán)謹(jǐn)?shù)目茖W(xué)素養(yǎng)淀粉組成StarchComposition01CONTENTS目錄淀粉性質(zhì)Starchproperties02淀粉分離Starch

Isolation03淀粉制糖Starch

hydrolysates04一、

淀粉組成StarchComposition直鏈淀粉（Amylose）

D-葡萄糖基以a-(1,4)糖苷鍵連接的多糖鏈聚合度（degreeofpolymerization，DP）:180-320,分子量（molecularweight，MW）~106.Branchapproximatelyevery200glucoseunits支鏈淀粉（Amylopectin）a-（1，4）糖苷鍵的糖鏈外，還有a-（1，6）糖苷鍵連接的分支MW~108Amylose:amylopectin~1:3WaxystarchesallamylopectinHighamyloseupto70%amylose第五章

淀粉加工Chapter5StarchprocessingAmyloseLinearcomponentofstarch1,4-α-糖苷鍵Molecularweight:lessthan0.5million可形成線圈（coils），包埋碘（iodine）而變藍(lán)第六章

淀粉加工Chapter5StarchprocessingAmylopectinBranchedcomponentofstarchContains1,4-alpha-glucosidicaswellas1,6-alpha-glucosidicbondsMolecularweight:50-500millionLimitedcoilingcausespurplish-red（紫紅色）colorwheniodineadded第五章

淀粉加工Chapter5StarchprocessingStarchGranule支鏈淀粉在同心圓中形成，直鏈淀粉分散在中間通過氫鍵結(jié)合在一起顆粒在水中受熱時(shí)發(fā)生溶脹由于淀粉具有不溶于冷水和比重大于水兩個(gè)基本特征，這是淀粉得以制取的根本原因。由于制取淀粉的過程中需要大量用水，故有“水磨法”之稱（wet-milled）。第五章

淀粉加工Chapter5Starchprocessing

Amaranth（莧菜籽）starch(Bar:1μm)Arrowroot（竹芋）starch

(Bar:20μm)Buckwheat（蕎麥）starch

(Bar:5μm)

Cassava[k??sɑ:v?]starch

(Bar:10μm)Cornstarch

(Bar:10μm)Oatstarch

(Bar:5μm)

Potatostarch

(Bar:50μm)Ricestarch

(Bar:2μm)Kidneybeanstarch

(Bar:20μm)二、淀粉性質(zhì)

Starchproperties1.糊化（Pasting）、糊化（膠凝）（Gelatinization）當(dāng)?shù)矸墼谒屑訜釙r(shí),氫鍵斷裂，水進(jìn)入顆粒,顆粒膨脹,直鏈淀粉從顆粒中遷移出來水和支鏈淀粉之間的氫鍵增加自由水的減少改變了淀粉混合物的粘度，使其增稠第五章

淀粉加工Chapter5StarchprocessingStarchgelatinizationisthecollapse(disruptionofmolecularorder)withinthestarchgranule,manifestedinirreversiblechangesinproperties

suchasgranularswelling,nativecrystallinemelting,lossofbirefringence（雙折射）

andstarchsolubilization.”Unheatedpotatostarchgranule（25℃）Heatedstarchgranule1.糊化（Pasting）、糊化（膠凝）（Gelatinization）“Pastingisthephenomenonfollowinggelatinizationinthedissociationofstarch.

Pasting是淀粉在解離過程中發(fā)生糊化后的現(xiàn)象Itinvolvesgranularswelling,exudation滲出ofmolecularcomponentsfromthegranule;andeventuallythetotaldisruptionofthegranules.”第五章

淀粉加工Chapter5StarchprocessingRaw,uncookedstarchgranulesheatedinwaterSwellingisevidentNoticelossofamylosefromthegranulesGelatinizationandpastingarecomplete

Somegranuleshavecollapsed.Nowwestarttocool.GelationNoticeareasofassociation.Thesearecalledjunctionzones.Thispictureisnotyetcompleteaswehaven’taccountedforthewaterinthesystem.waterwaterwaterwaterwaterwaterThisisastarchgelEffectofcontinuousheatinginexcesswaterResultsinformationofstarchpastedueto:furthergranuleswellingbeyondreversiblepointadditionalleachingofsolublecompoundstotaldisruptionofgranulesViscosityandTypeofStarch纖維素納米晶對(duì)甘薯淀粉糊化特性的影響Gel

連接起來的分子或粒子形成的連續(xù)的三維網(wǎng)絡(luò)，將大量的連續(xù)液相包裹起來，就像海綿一樣在許多食品中，凝膠網(wǎng)絡(luò)由聚合物分子或由聚合物分子通過氫鍵、疏水締合、離子交叉橋、纏結(jié)或共價(jià)鍵連接在結(jié)合部位形成的纖維組成，液相是低分子量溶質(zhì)和部分聚合物鏈的水溶液。三、淀粉分離StarchIsolationStarchcanbeextractedusingvariousprocesses,dependingontheplantsourceandenduseofthestarch.Wetmillingprocessingiswidelyusedincerealstarchproduction.

濕磨加工在谷物淀粉生產(chǎn)中應(yīng)用廣泛。Thepurposeofwetmillingistoseparatethekernel(grain)intoitsconstituentchemicalcomponents.濕磨的目的是將籽粒(谷物)分離成其組成化學(xué)成分Figure7.1presentsthemajorproceduresforextractingstarchesfromcerealgrainsandtubers.第五章

淀粉加工Chapter5Starchprocessing玉米淀粉生產(chǎn)的基本工藝流程Themainpurposesofthesteepingprocessaretoloosenthegranulesinthepackedcellstructure.

浸泡過程的主要目的是疏松堆積細(xì)胞結(jié)構(gòu)中的顆粒。flashdryer氣流干燥器四、淀粉制糖Starchhydrolysates淀粉糖是以淀粉為原料，通過酸或酶的催化水解反應(yīng)生產(chǎn)的糖品的總稱，是淀粉深加工的主要產(chǎn)品。Thehydrolysisofstarchtosweetenersbymineralacidwasdiscoveredin1811.Enzymesareemployedtoproducestarchfromsyrupswithapreponderanceofmaltoseorglucoseandtoisomerizesomeoftheglucoseinhigh-glucosesyrupstofructose,soastoenhancesweetness.酶被用來從以麥芽糖或葡萄糖為主的糖漿中生產(chǎn)淀粉，并將高葡萄糖糖漿中的一些葡萄糖異構(gòu)化為果糖，以提高甜度。第五章

淀粉加工Chapter5Starchprocessing1.淀粉糖的種類與性質(zhì)

TypesofStarchhydrolysatesGeneralclassificationsofsweetenersareasfollows1.Cornsyrup(glucosesyrup):Thepurified,concentratedaqueoussolutionofnutritivesaccharidesobtainedfromediblestarchandhavingaDEof20ormore.玉米糖漿(葡萄糖漿)：從食用淀粉中獲得的、DE為20或更多的營養(yǎng)性糖的純化、濃縮水溶液2.Driedcornsyrup(driedglucosesyrup):Cornsyrupfromwhichthewaterhasbeenpartiallyremoved.2.干玉米糖漿(干燥葡萄糖糖漿)：部分去除水的玉米糖漿。3.Dextrosemonohydrate:PurifiedandcrystallizedD-glucose,containingonemoleculeofwaterofcrystallization.

水合葡萄糖：純化結(jié)晶的D-葡萄糖，含有1分子結(jié)晶水。4.Dextroseanhydrous:PurifiedandcrystallizedD-glucosewithoutwaterofcrystallization.

無水葡萄糖：純化結(jié)晶的D-葡萄糖，不含結(jié)晶水。1.淀粉糖的種類與性質(zhì)

TypesofStarchhydrolysates5.Maltodextrin:Apurified,concentratedaqueoussolutionofnutritivesaccharidesobtainedfromediblestarchorthedriedproductderivedfromsaidsolutionandhavingaDEoflessthan20.5.麥芽糖糊精：從食用淀粉或從該溶液中提取的干燥產(chǎn)品中獲得的營養(yǎng)糖的純化、濃縮水溶液，其DE值小于20。6.HFCS(High-fructosecornsyrup):Apurified,concentratedaqueoussolutionofnutritivesaccharidesobtainedfromediblestarchandhavingaportionoftheglucoseisomerizedtofructose.6.HFCS(高果糖玉米糖漿)：一種純化的、濃縮的營養(yǎng)性糖水溶液，從食用淀粉中獲得，部分葡萄糖異構(gòu)化為果糖。1.淀粉糖的種類與性質(zhì)

TypesofStarchhydrolysates淀粉糖工業(yè)常用葡萄糖值(dextroseequivalent)簡稱DE值(糖化液中還原性糖全部當(dāng)做葡萄糖計(jì)算，占干物質(zhì)的百分率稱葡萄糖值)來表示淀粉水解的程度。DEofaproductofhydrolysisisitsreducingpowerasa%ofreducingpowerofpuredextrose(D-glucose)1.淀粉糖的種類與性質(zhì)

TypesofStarchhydrolysates2.生產(chǎn)方法

ProductionmethodsStarch,gelatinizedbyheat,maybehydrolyzedbyacid,enzyme,orbyacombinationofthetwo,dependingonthepropertiesrequiredintheproduct.淀粉經(jīng)熱糊化后，可能被酸、酶或兩者的組合水解，這取決于產(chǎn)品所需的性質(zhì)。Thekeytogoodconversionisuniformityoftreatmentsoastominimizeresidualtracesoflong-chainmolecules,whichtendtoreassociate,givingahazyproduct-partofthephenomenonofretrogradation.良好轉(zhuǎn)換的關(guān)鍵是處理的均勻性，以盡量減少長鏈分子的殘留，這些分子往往會(huì)重新結(jié)合，從而產(chǎn)生一種模糊的產(chǎn)品--部分老化現(xiàn)象。（1）Acidhydrolysis(conversion)Apartialhydrolysisofstarchisreadilycarriedoutbytreatmentwithacidathightemperature.淀粉的部分水解很容易通過高溫下的酸處理進(jìn)行。Moderninstallations

utilizecontinuous-flowpressurizedreactorsinwhichtheacidifiedstarchismaintainedatatemperatureof135-150℃for5-8min.現(xiàn)代裝置采用連續(xù)流動(dòng)加壓反應(yīng)釜，其中酸化淀粉在135-150℃的溫度下保持5-8分