氢化棕榈硬脂结晶特性及其对蜡烛外观的影响.docx

氢化棕榈硬脂结晶特性及其对蜡烛外观的影响赵雪丹1，肖宇峰2，许淑芳2，徐学兵1，2，毕艳兰1，张虹1，2(1．河南工业大学粮油食品学院，郑州450001;2．丰益(上海)生物技术研发中心有限公司，上海200137)摘要:为解决分提棕榈硬脂用作蜡材时渗油的问题，对其进行了不同程度的氢化。利用差示扫描量热仪、脉冲核磁共振仪、偏振光显微镜和X－射线衍射仪等手段对其结晶行为进行研究，并比较了氢化前后化学组成的变化。结果表明:棕榈硬脂氢化的第一个阶段，部分油酸和亚油酸迅速转变为反式油酸，它促进了α型晶体的形成及其向β型的转变，虽然45℃以下时固体脂肪含量高于原料油，但其熔点却降低;氢化的第二个阶段，大量油酸和反式油酸转变为硬脂酸，高熔点组分增加，虽然晶型仍处于β型，但此时熔点及各温度下的固体脂肪含量均高于原料油。氢化15min后低熔点峰基本消失，蜡烛渗油现象也消失;继续氢化至20min后样品结晶峰狭窄、尖锐，蜡烛容易断裂。因此，适度氢化样品(氢化15～20min)较适合用作蜡材。关键词:棕榈硬脂;氢化;结晶行为;蜡烛中图分类号:TS224;TQ645文献标志码:A文章编号:1003－7969(2014)09－0074－06CrystallizationcharacteristicsofhydrogenatedpalmstearinanditsinfluenceonappearanceofcandleZHAOXuedan1，XIAOYufeng2，XUShufang2，XUXuebing1，2，BIYanlan1，ZHANGHong1，2(1．CollegeofFoodScienceandTechnology，HenanUniversityofTechnology，Zhengzhou450001，China;2．Wilmar(Shanghai)BiotechnologyＲ＆DCenterCo．，Ltd．，Shanghai200137，China)Abstract:Fractionatedpalmstearinwashydrogenatedatdifferentdegreesinordertosolvetheproblemofgreasyappearanceasarenewablecandlematerial．Thecrystallizationbehaviorofhydrogenatedpalmstea-rinwasstudiedbydifferentialscanningcalorimetry，nuclearmagneticresonance，X－raydiffractionandpolarizedlightmicroscopy，andthechemicalcompositionsofpalmstearinandhydrogenatedpalmstearinwerecompared．Theresultsshowedthatinthefirststageofhydrogenation，partofoleicacidandlinoleicacidrapidlyconvertedtotrans－oleicacid，whichpromotedtheformationofαtypecrystalanditstrans-formationtoβtypecrystal;thoughthesolidfatcontentofhydrogenatedpalmstearinbelow45℃washigherthanthatofpalmstearin，itsmeltingpointreduced;inthesecondstageofhydrogenation，plentyofoleicacidandtrans－oleicacidconvertedtostearicacid，therebythecontentofcomponentswithhighmeltingpointincreased，andthesolidfatcontentsatalltemperaturesandthemeltingpointwerealsohigh-erthanthoseofpalmstearinalthoughthecrystalwasstillβtype．Thelowmeltingpointpeakdisap-pearedafterpalmstearinwashydrogenatedfor15min，andthegreasyappearanceofcandledisappearedaswell;whenhydrogenationtimewasmorethan20min，thecrystallizationpeakbecamesharpandnar-row，andthecracki