高油酸花生油酶促酯交换合成类可可脂工艺优化

为促进高油酸花生油的高值化利用,在无溶剂体系中以高油酸花生油为原料,棕榈酸乙酯、硬脂酸乙酯为酰基供体,酶促酯交换合成类可可脂。以目标甘三酯1,3-二棕榈酸-2-油酸(POP)、1-棕榈酸-2-油酸-3-硬脂酸(POS)、1,3-二硬脂酸-2-油酸(SOS)含量,硬脂酸指数和酰基位移率为评价指标,在单因素实验的基础上采用响应面法对酶促酯交换合成类可可脂的工艺条件进行优化。结果表明：酶促酯交换合成类可可脂的最佳工艺条件为硬脂酸乙酯与棕榈酸乙酯物质的量比1.3∶1、酰基供体与高油酸花生油物质的量比12∶1、加酶量2.7%(以底物质量计)、反应温度60℃、反应时间7 h,在该条件下产物甘三酯中POP、POS、SOS的含量分别为14.55%、48.87%、25.17%,硬脂酸指数为0.56,酰基位移率为7.35%。产物的目标甘三酯组成和脂肪酸组成与可可脂相近,可作为可可脂替代品应用。     

影响酶催化制备类可可脂过程中酰基位移和酯交换因素研究

该文研究棕榈油中间熔点物(POMF)与硬脂酸(StA)进行酶酯交换制备类可可脂。利用胰脂酶定向水解和Lipozyme TL IM脂肪酶酯交换的特性,结合TLC和GC法分析Sn–2位酰基转移率和酯交换的程度。从而得出棕榈油中间物制备类可可脂的反应条件:POMF为5 g,水活度为0.43,加酶量为10%,底物质量比为1∶1.8,振荡速度为150 r/min,反应温度60℃,反应时间10 h。此时,酯交换程度为75.70%,酰基转移率为12.30%,产品的滑动熔点为31³5℃,酸值为1.2mgKOH/g。     

无溶剂系统酶促POMF酯交换反应生产CBE的正交实验研究

本文运用正交实验研究了在无溶剂系统中,利用1,3位置特异性脂肪酶催化POMF与硬脂酸甲酯进行酯交换反应制取类可可脂。结果表明：应以Lipozyme IM做为催化剂,反应温度为55℃,振荡速度为150r／min,酶／底物配比为300U／10g,硬脂酸甲酯／POMF配比为1,且其产品经过差示扫描量热法（DSC）分析,热性能符合类可可脂质量的要求。     

茶油酶促改性一步反应影响因素研究

中国南方几省茶油有一定产量，而国外茶油产量极小，基本上没有市场。利用茶油的特殊结构进行酶促改性制类可可脂很少见有报道。选择１，３位定向脂肪酶，在茶油、硬脂酸、软脂酸混合非水溶剂（己烷）体系中进行一步酯交换反应，最终制出了类似可可脂结构和组成的代用品。本研究主要对茶油酶促改性的主要影响因素进行了探讨。     

1-棕榈酸-2-油酸-3-硬脂酸甘油三酯对巧克力霜变行为的影响机制及其酶法制备研究进展

类可可脂具备与可可脂一致的甘油三酯类型,以单不饱和对称型甘油三酯为主要组成,合理开发类可可脂资源可解决可可脂供不应求的困境,然而目前关于类可可脂的理解、制备和应用还存在诸多问题。介绍了具备工业化开发前景的类可可脂资源,论述了在单不饱和对称型甘油三酯体系中缺乏1-棕榈酸-2-油酸-3-硬脂酸甘油三酯（POSt）易引发巧克力起霜的机制,指出该问题已成为类可可脂应用的一大瓶颈;进而基于不同的脂质底物,提出酶法酯交换制备富含POSt类可可脂的技术路径。     

酶促酯交换桕脂的改性

在脂肪酶 Lipozyme 的作用下,将桕脂与硬脂酸甲酯(SME)或硬脂酸甘油酯(SSS)酯交换,可获得一种可可脂类似物.其三甘酯组成与可可脂极为相似,主要三甘酯为 POS 与 SOS(P:棕榈酸;O:油酸;S:硬脂酸)。在对脂肪酶作用原理讨论之后,给出了其在油脂工程中进一步应用的可能性。     

高油酸花生油酶促酯交换制备1,3-二棕榈酸-2-油酸甘油三酯

旨在为可可脂生产提供新的基料油,同时为高油酸花生油的高值化利用提供研究基础,以高油酸花生油和棕榈酸乙酯为原料,脂肪酶NS40086为催化剂,在无溶剂体系下酶法合成1,3-二棕榈酸-2-油酸甘油三酯(POP)。采用单因素实验研究反应条件对POP含量、酰基位移、sn-2位油酸相对含量的影响,并采用响应面法进行优化。结果表明：高油酸花生油酶促酯交换制备POP的最佳反应条件为反应时间3 h、底物(棕榈酸乙酯与高油酸花生油)物质的量比11∶1、酶添加量(以底物总质量计)3%、反应温度50℃,在此条件下POP含量为86.48%,酰基位移为3.25%,sn-2位油酸相对含量为72.88%。     

棉籽油与棕榈硬脂化学酯交换法制备零反式脂肪酸起酥油的研究

通过研究甲醇钠催化棕榈硬脂和棉籽油酯交换反应,以酯交换产物在20℃条件下固体脂肪含量(SFC)为指标,考察了反应温度、催化剂用量、反应时间对酯交换反应的影响。确定的最佳酯交换条件为:反应温度90℃,催化剂用量0.5%,反应时间60 min。通过酯交换产物SFC与市售焙烤型起酥油全统酥油SFC比较以及晶型分析,得出棕榈硬脂与棉籽油质量比为1∶1的酯交换产物,其SFC与市售焙烤起酥油全统酥油相似,结晶形态为β'型,且不含反式脂肪酸,符合零反式脂肪酸起酥油性质要求,适宜用作焙烤起酥油。     

有机相中脂肪酶催化棕榈油酯交换反应生产代可可酯的研究

本文研究在有机相中,固定化1,3-位置特异性脂肪酸Lipozyme~(IM)催化棕榈油中的区分物(POMF)与硬脂酸之间的酯交换反应,考察了反应温度、有机溶剂、酰基供体、酶浓度、水活性等因素对酯交换反应的速度和产物组成的影响。由棕榈油生产代可可脂的最佳反应条件是:Lipozyme~(IM):POMF:硬脂酸:正庚烷=1:3:6:9(wt/％),a_w=0.55,温度60～65℃。     

樟树籽油酯交换法制备生物柴油的研究

以浓H2SO4为催化剂,樟树籽油与甲醇预酯化生成酯化油;再以NaOH为催化剂,酯化油与甲醇进行酯交换制备生物柴油。在单因素试验的基础上,利用正交试验优化酯交换反应条件。结果表明:当甲醇与酯化油摩尔比为4.0∶1、催化剂与酯化油摩尔比为0.050∶1、反应时间为80 min、反应温度为55℃时,酯交换率最高,达94.38%。经气相色谱分析,樟树籽油生物柴油的脂肪酸甲酯组成为:癸酸甲酯53.67%,月桂酸甲酯42.92%,肉豆蔻酸甲酯0.44%,棕榈酸甲酯0.37%,油酸甲酯2.11%,亚油酸甲酯0.26%。     

Enzymatic synthesis of cocoa butter analog through interesterification of lard and tristearin in supercritical carbon dioxide by lipase

Substrate oil composition, reaction time, acyl donor, temperature, and pressure affected the triacylglycerol (TG) content of cocoa butter analog during the interesterification reaction catalyzed by lipase in a supercritical carbon dioxide (SC-CO₂) system. Among oil sources used to interact with tristearin, the content of 1(3)-palmitoyl-3(1)-stearoyl-2-monoolein (POS) (P, palmitate; O, oleate; S, stearate) and 1-palmitoyl-2, 3-dioleoylglycerol (POO) in analog was most similar to the corresponding TG content of cocoa butter when analog was prepared with lard. The optimized interesterification reaction using lard and tristearin (at a mole ratio of 1.4) as substrates to produce cocoa butter analog in a SC-CO₂ system was at 17 MPa, 50 °C, pH 9, for 3 h with an immobilized lipase, Lipozyme IM-20, from Mucor miehei. The lyophilized enzyme facilitated the production of cocoa butter analog in anhydrous substrates (a_w 0.33). The yield and melting point of the purified cocoa butter analog by a silica column was 63% and 34.5 °C, respectively, when the analog was produced under optimal conditions.     

Cocoa butter equivalent from enzymatic interesterification of tea seed oil and fatty acid methyl esters

Cocoa butter equivalent (CBE) was prepared by interesterification of tea seed oil, methyl palmitate and methyl stearate with lipase. The lipase was immobilized on macroporous resin selected from eight carriers. The rate of reaction of lipase immobilized on macroporous resin was 6.9 times higher than that of the free enzyme. After repeating application five times, 83.50% activity, of the immobilized lipase, was retained. Factors such as reaction time, temperature, water content, enzyme load and substrate ratio were studied. Three major acyls (palmitoyl, oleoyl and stearoyl) in triacylglycerols of the product were similar to those of cocoa butter. The melting range and dilatation–temperature curves of the prepared CBE were close to that of the cocoa butter.     

均匀设计在酯化樟树籽油制备单甘酯中的应用

以樟树籽油为原料、对甲基苯磺酸为催化剂,通过酯化将樟树籽油中的游离脂肪酸转化为单甘酯。采用均匀设计和偏最小二乘回归法,以酯化率(Y1)和单甘酯的含量(Y2)的最大值为优化目标,考察反应温度、催化剂的用量、醇油物质的量配比、反应时间对樟树籽油酯化反应的影响。对两个试验指标进行回归建模,模型拟合的决定系数分别为0.9801、0.9739。最优目标函数值Y1、Y2 分别为98.2%、12.2%,实测值分别为95.6%、14.4%,最佳酯化反应条件为反应温度132℃、催化剂的用量3.5%(油重)、醇油物质的量配比1.8:1、反应时间2h。     

固体碱催化合成中碳链脂肪酸聚甘油酯

以聚甘油、樟树籽仁油脂肪酸为原料,固体碱KOH/Al2O3为催化剂,催化酯化合成中碳链脂肪酸聚甘油酯.采用单因素试验研究反应温度、反应时间、聚甘油与中碳链脂肪酸质量比、催化剂用量对酯化率的影响,通过正交试验优化中碳链脂肪酸聚甘油酯的合成工艺.最优合成工艺条件为反应温度220℃、反应时间2.5h、聚甘油与中碳链脂肪酸质量比2∶1、催化剂用量4.5％,该条件下酯化率为87.5％,所得中碳链脂肪酸聚甘油酯的酸值(KOH)、皂化值(KOH)、碘值(Ⅰ)、熔点分别为1.86 mg/g、148.4 mg/g、2.9 g/100 g、47.3℃.     

Fatty acid tryptamides as shell indicators for cocoa products and as quality parameters for cocoa butter

The methods used to date to determine the shell content in cocoa products are very time-consuming, protracted and not specific enough, meaning that with the development of a new high-performance liquid chromatography (HPLC) method using fluorescence detection, a considerably more specific process is now available. Fatty acid tryptamides can be drawn on as indicator substances for detecting the shell content in cocoa products. The relevant substance species are docosanoyl-2-(3-indolyl)ethylamide (behenic acid tryptamide, BAT) and tetracosanoyl-2-(3-indolyl)ethylamide (lignoceric acid tryptamide, LAT). To allow conclusions on the average levels of fatty acid tryptamides (FAT) in cocoa products to be drawn, 433 cocoa samples were analysed. The natural tryptamide concentrations in cocoa shells and cocoa nibs or cocoa liquors varied significantly. The average ratio of cocoa shells to cocoa nibs/cocoa liquors is 16:1. As a result of these differences in concentration, the shell content can be determined with a high degree of accuracy via the fatty acid tryptamides in cocoa. This method also allows conclusions to be drawn on the quality of cocoa butter. The tryptamide concentrations in pressed cocoa butter and in expeller butter respectively vary greatly, so that it is possible through the FAT levels determined to gain an insight into the method of production of cocoa butter.     

添加茶多酚对茶籽油酸值的影响

茶多酚是茶叶中提取的一种天然抗氧剂,具有优良的抗氧化性能。本实验以茶多酚为添加剂,考察了紫外光、温度、CuCl2和KClO3对茶籽油酸值的影响。实验结果表明,分别用紫外光辐射和90℃加热7h,添加茶多酚茶籽油的酸值比不加茶多酚分别低22.8%和12.06%;用0.08mol/LCuCl2和KClO3氧化7h,添加茶多酚茶籽油的酸值比不加茶多酚分别低3.63%和7.63%。     

Enzymatically modified tea seed oil as cocoa butter replacer in dark chocolate

Cocoa butter replacer (CBR) was prepared by enzymatic interesterification of hydrogenated and solid fraction (SF) of tea seed oil at weight percent ratio of 30:70, using sn‐1,3 specific lipase from Thermomyces lanuginosus. Dark chocolate samples were then prepared with the prepared CBR as a replacement for 5%, 10%, 15% and 20% of cocoa butter (CB) and the effect of the replacement on hardness (as a key quality factor in chocolate) of the chocolate samples was investigated. Results showed that chocolate samples containing 5% and 10% of interesterified sample (EIS), had the closer texture to that of CB chocolate than other samples. The solid fat content (SFC) profiles also revealed that blending 10% of EIS with CB in chocolate formulation dose not affect the sharp melting point of CB. Based on the results taken from bloom formation, polymorphic structure and sensory evaluation, adding up to 10% of EIS in chocolate formulation reduces the bloom development without adverse affecting the desirable β crystal formation and sensory qualities in the chocolate samples.     

非水相酶促酸解制备类可可脂的工艺研究

在非水相条件下,利用固定化脂肪酶催化棕榈油中熔点分提物(POMF)与硬脂酸(St)进行酸解反应制备类可可脂(CBE).考察了不同固定化酶、酶添加量、反应溶剂、酶的水分活度、底物质量比和反应温度对反应产率、速率以及产物中甘三酯组成的影响.结果表明:Lipozyme RM IM<'IM>添加量8%(以底物质量计),环己烷为溶剂,酶水分活度0.54,St与POMF质量比2:1,反应温度60℃为最佳酸解条件;在此条件下反应150 min,产物中主要甘三酯POP、POS、SOS含量分别达到19.36%、44.17%和25.54%.这与天然可可脂组成(POP 18%、POS 42%、SOS 27%)较为相似,满足CBE指标要求.     

水酶法提取茶叶籽油工艺条件研究

采用水酶法提取茶叶籽油,通过单因素实验和正交实验优化提取工艺条件。结果表明,水酶法提取茶叶籽油优化工艺条件为:纤维素酶用量1.1%、果胶酶用量2.0%、蛋白酶用量0.2%,料液比1:6,酶解温度45℃、酶解pH值5.0、酶解时间8h,茶叶籽油得率28.64%。     

响应面优化超声波辅助水酶法提取茶叶籽油工艺

利用响应面法(RSM)优化超声波辅助水酶法提取茶叶籽油工艺条件,在单因素试验基础上,选取复合酶用量、酶解pH、酶解温度、酶解时间为影响因子,茶叶籽油得率为响应值,应用Box-behnken中心组合试验设计建立数学模型,进行响应面分析。结果表明,超声波辅助水酶法提取茶叶籽油工艺优化条件为:高压蒸煮20min,超声处理20min,超声温度60℃,料液比1:5、复合酶用量1.75%,酶解pH4.6,酶解温度44℃,酶解时间6.9h。茶叶籽油得率为29.88%。