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1.
酯交换是重要的油脂改性技术之一,其改性过程中不产生反式脂肪酸。酯交换方法可采用工业酶法和化学法,这两种方法对原料油的含磷量、含水量和过氧化值都有很高的要求,生产出的产品性能较为相近。化学法酯交换通常采用批次式生产,过程中需要采用碱性催化剂。酶法酯交换反应器一般由多个固定化床串联,可以实现连续生产,但酶需要定期更换。酯交换方法的选择需要综合考虑投资费用、操作费用、操作稳定性等因素。  相似文献   

2.
以棕榈硬脂、油茶籽油及棕榈仁油为原料,利用酶法酯交换制备塑性脂肪。在单因素实验的基础上,采用Design Expert软件进行响应面优化设计,反应条件包括:反应时间、反应温度和酶添加量,以滑动熔点作为衡量指标。优化后得到最优反应条件为:反应时间4.2h,反应温度64℃,酶添加量为7.2%,在最优反应条件下的酶法酯交换产物的实际滑动熔点可达37.9℃。对物理混合、酶法酯交换以及化学酯交换样品进行了氧化稳定性研究,在储藏30d内物理混合样品的过氧化值为1.13~120.46meq/kg,低于酶法酯交换样品(1.16~138.88meq/kg)及化学酯交换样品(1.26~148.49meq/kg)。物理混合样品的氧化稳定性高于酶法酯交换样品,酶法酯交换样品的氧化稳定性高于化学酯交换样品。  相似文献   

3.
利用固定化脂肪酶催化棕榈油硬脂和葵花籽油进行酯交换反应,制备零反式脂肪酸涂抹脂基料油。考察了不同搅拌速度、反应温度、酶加量和反应时间对酯交换反应的影响,并对反应前后油脂的熔点、晶型和结晶速率等结晶行为进行了分析和比较。结果表明:搅拌速度200 r/min,酶加量6%,在70℃下反应3 h为最优的酯交换条件。酯交换产物的熔点大幅下降,晶型主要以β’晶型为主,结晶速率变慢。  相似文献   

4.
研究了以猪油和棕榈硬脂为原料经酶法酯交换制备的零反式脂肪酸起酥油的性质。相同质量的猪油和棕榈硬脂在反应温度60℃、固定化酶用量8%(以底物质量计)、反应时间1 h的条件下进行酯交换反应。通过对混合油酯交换前后的晶体形态、熔化性质、甘油三酯组成、脂肪酸组成分析发现:经酯交换后混合油结晶更加均匀细腻;混合油甘油三酯组成发生显著变化,不对称甘油三酯含量显著增加;混合油脂肪酸组成基本无变化,无反式脂肪酸生成;酪化性显著变好。  相似文献   

5.
在油脂酯交换反应过程中,产物油脂往往需要进行Sn-2位脂肪酸组成的鉴别与分析,由于反应生成物(如脂肪酸,脂肪酸甲酸,甘三酯,甘一酯,甘二酯等)的性质十分相似,要研究酯交换过程中甘三酯的Sn-2位脂肪酸组成,所需要甘三酯的量往往需要很多块TLC板的分离才能实现,致使实验费用增加,效率降低,本文主要研究了脂肪酸,脂肪酸甲酯以及硅胶对油脂Sn-2位脂肪酸的影响。实验结果证明:脂肪酸、脂肪酸甲酸以及硅胶在一定的条件下不影响油脂Sn-2位脂肪酸组成分析的结果,这种方法是对国际纯粹化学和应用化学联合会(IUPAC)方法的改进和补充,大大简化了分析过程,可以广泛地应用于相关的研究与分析中。  相似文献   

6.
研究了固定化脂肪酶Lipozyme RM IM催化猪油和棕榈硬脂酯交换制备起酥油的工艺,考察了反应温度、酶添加量、反应时间对酯交换反应的影响.并以反应后体系在20℃下的固体脂肪含量(SFC)为指标,确定了理想的工艺条件:反应温度60℃,酶添加量8%,反应时间1h.利用等温曲线和X-射线衍射技术研究了混合体系酯交换前后的相容性和晶体形态,结果表明:经酯交换后,混合体系的相容性得到显著改善,晶型由β型转变为β’型,适宜用作焙烤起酥油.  相似文献   

7.
以丝瓜籽为原料,研究水酶法提取丝瓜籽油的最佳工艺并对其脂肪酸组成、理化特性进行分析。经单因素试验与混料试验,确定了水酶法提取丝瓜籽油的分步酶解条件为:首先添加2.0%的复合酶(其中维素酶、果胶酶、半纤维素酶的配比为0.663∶0.237∶0.100),在pH 4.8、温度45℃、液料比7∶1条件下,酶解2.5 h;再加入1.0%的中性蛋白酶,在pH 6.8、温度45℃条件下,酶解1.5 h,最终丝瓜籽油提取率达到93.85%。该油富含不饱和脂肪酸,其酸价、过氧化值等指标符合国家食用油卫生标准。水酶法提取丝瓜籽油是一种有效的油脂提取方法。  相似文献   

8.
研究了以大豆油和极度氢化棕榈油为原料,采用脂肪酶Lipozyme TLIM催化酯交换反应制备的零反式脂肪酸食品专用油脂基料的性质。酶法酯交换反应条件为反应温度60℃、反应时间3 h、酶添加量4%(占油脂总质量)、大豆油与极度氢化棕榈油质量比4∶3。对比了酯交换反应前后混合油脂的热性质、固体脂肪含量、晶体形态和微观形态。结果表明:酶法酯交换反应后,产物熔融、结晶温度均降低;酯交换产物以β'晶型为主,晶体颗粒均匀、较小;当温度高于25℃后固体脂肪含量减小,产物在高于45℃时可全部融化。因此,酯交换油脂适用于制备烘焙型食品专用油脂基料。  相似文献   

9.
10.
水溶性蜂王浆酶法制备条件的优化及其特性的研究   总被引:1,自引:0,他引:1  
采用4种不同蛋白酶水解蜂王浆,研究水解物的特性和酶作用条件.研究结果表明,不同蛋白酶对蜂王浆的水解效果不同,以复合植物蛋白酶的水解效果较好,其最佳水解条件为:水解时间2 h,底物浓度1:3(W/V),酶用量为鲜浆的0.3%,pH 8.0,加热温度50℃.所制备的酶解物的酸、热稳定性及水溶性均优于原浆.  相似文献   

11.
利用脂肪酶Lipozyme TLIM催化棕榈硬脂(PS)与大豆油(SO)(PS∶SO分别为9∶1,8∶2,7∶3,6∶4,5∶5,wt%)酯交换反应,研究酯交换反应前后混合油脂体系中甘三酯组成的变化及其与油脂物理性能的关系。结果发现,酯交换后油脂中PPP、LLL、POP、PPL、PLL、PLO六种甘三酯含量发生明显变化,其中PPP、LLL含量下降,PPL、PLL、PLO含量增加,而POP除9∶1外,其含量均下降;SSS(S代表饱和脂肪酸)和UUU(U代表饱和脂肪酸)型甘三酯含量下降,而SUU和SUS含量增大,导致油脂熔点和固体脂肪含量(SFC)均不同程度下降,从而可制备不同SFC要求的塑性脂肪。PS∶SO为7∶3、6∶4、5∶5时,酯交换后油脂β’晶型增多,可为人造奶油、速冻专用油脂等塑性脂肪提供理想晶型。   相似文献   

12.
The effect enzymatic interesterification (EIE) on the functional performances of beef tallow (BT) blended with coconut oil (CO) in varying proportions was investigated. BT and three different proportions of CO, containing 20%, 30% or 40% CO were interesterified in a solvent-free system with a commercial immobilised lipase, Lipozyme TL IM. The interesterified oils (IOs) were also processed into margarines, and their textural properties, microstructure as well as their sensory properties, were determined. The IO with 40% CO has the best properties for margarine production, with a low content of high melting-point triacylglycerols, which should minimise the ‘waxy’ mouth-feel of BT-based margarines. The fat in IO-based margarine (M-IO) was mainly in the β′ crystal form and the crystals were more evenly distributed than in BT-based margarine (M-BT). A sensory and textural evaluation determined that the texture of M-IO was more compact, and that its colour and flavour were better than M-BT. The IO obtained may be used as a base oil to replace BT in margarine and has potential application in the margarine industry.  相似文献   

13.
进行了固定化脂肪酶Lipozyme TL IM催化棕榈油硬脂和大豆油酶法酯交换的研究,考察了酶法酯交换分批操作的反应动力学曲线,发现5%的加酶量、70℃下反应,反应3 h内达到平衡,反应温度在70~90℃对反应速度无明显影响。采用填充床式反应器进行连续反应,结果表明通过装有10 g脂肪酶柱子的最佳流速为30 g/h。对化学酯交换和酶法酯交换产品性质的比较发现,二者SFC无明显差异。采用填充床式反应器对40∶60和30∶70的棕榈油硬脂和大豆油的混合物进行酶法酯交换反应,测定了反应产物的SFC曲线,为将来的应用开发提供参考数据。  相似文献   

14.
Tang L  Hu JN  Zhu XM  Luo LP  Lei L  Deng ZY  Lee KT 《Journal of food science》2012,77(4):C454-C460
It is known that Cinnamomum camphora seed oil (CCSO) is rich in medium-chain fatty acids (MCFAs) or medium-chain triacylglycerols (MCTs). The purpose of the present study was to produce zero-trans MCTs-enriched plastic fat from a lipid mixture (500 g) of palm stearin (PS) and CCSO at 3 weight ratios (PS:CCSO 60:40, 70:30, 80:20, wt/wt) by using lipase (Lipozyme TL IM, 10% of total substrate) as a catalyst at 65 °C for 8 h. The major fatty acids of the products were palmitic acid (C16:0, 42.68% to 53.42%), oleic acid (C18:1, 22.41% to 23.46%), and MCFAs (8.67% to 18.73%). Alpha-tocopherol (0.48 to 2.51 mg/100 g), γ-tocopherol (1.70 to 3.88 mg/100 g), and δ-tocopherol (2.08 to 3.95 mg/100 g) were detected in the interesterified products. The physical properties including solid fat content (SFC), slip melting point (SMP), and crystal polymorphism of the products were evaluated for possible application in shortening or margarine. Results showed that the SFCs of interesterified products at 25 °C were 9% (60:40, PS:CCSO), 18.50% (70:30, PS:CCSO), and 29.2% (80:20, PS:CCSO), respectively. The β' crystal form was found in most of the interesterified products. Furthermore, no trans fatty acids were detected in the products. Such zero-trans MCT-enriched fats may have a potential functionality for shortenings and margarines which may become a new type of nutritional plastic fat for daily diet.  相似文献   

15.
利用固定化脂肪酶Lipozyme TLIM催化质量比为38∶3的天然可可脂与亚麻籽油进行酯交换反应,得到熔点为(36.52±0.34)℃的油脂(称为酯交换可可脂)。酯交换可可脂中亚麻酸的含量由反应前0.64%±0.01%升高至3.10%±0.28%,主要甘三酯POP、POS和SOS的含量由84.52%降至62.72%,低熔点甘三酯UUU和SUU含量分别由0.92%和6.85%增加至10.94%和16.60%。酯交换可可脂的固体脂肪含量(SFC)在5~30℃时低于天然可可脂的SFC,但其随温度变化的趋势与天然可可脂的相一致,当温度高于34℃时,酯交换可可脂的SFC略高于天然可可脂的SFC,37℃时酯交换可可脂的SFC为1.64%。以酯交换可可脂为原料制备的含亚麻酸巧克力表面光滑,口感细腻,具有可可和亚麻籽油独特的香味。加速氧化实验结果表明该巧克力20℃时的货架期为428 d,约61周,具有良好的贮藏稳定性。   相似文献   

16.
The structure of triacylglycerols in vegetable oil blends was enzymatically modified, and the blends were incorporated into skim caprine milk to produce goat milk-based infant formula analogs, homologous to human milk. A modified lipid containing palmitic, oleic, and linoleic acids, resembling the composition of human milk fat, was synthesized by enzymatic interesterification reactions between tripalmitin and a vegetable oil blend containing a 2.5:1.1:0.8 ratio of coconut, safflower, and soybean oils. A commercial sn-1,3-specific lipase obtained from Rhyzomucor miehei, Lipozyme RM IM, was used as the biocatalyst. The effects of substrate molar ratio and reaction time on the incorporation of palmitic, oleic, and linoleic acids at the sn-2 position of the triacylglycerols were investigated. The fatty acid composition and sn-2 position of the experimental formulas were analyzed using gas chromatography. Results showed that the highest incorporation of palmitic acid was obtained at 12 h of incubation at 55°C with a substrate molar ratio of 1:0.4 of tripalmitin to vegetable oil blend. However, the modified milk interesterified for 12 h at a 1:1 molar ratio had a greater resemblance to human milk compared with the other formulas. The level of oleic acid incorporation at the sn-2 position increased with the molar ratio of tripalmitin to vegetable oil blend. It was concluded that, unlike the original goat milk and other formulas, the formulated caprine milk with a molar ratio of 1:1 and a 12-h incubation was similar to the fatty acid composition of human milk.  相似文献   

17.
Abstract: Total of 3 different mixtures of rice bran oil (RBO), sheaolein (SO), and palm stearin (PS) (RBO : SO : PS, 40 : 35 : 25; 15 : 40 : 45; 10 : 35 : 55) were modified by enzymatic interesterification (EIE) using TLIM as a bio‐catalyst. After interesterification, a physicochemical properties of selected ratio (10 : 35 : 55; RBO : SO : PS) was compared with chemical interesterification (CIE). CIE sample showed higher SFC than EIE in each measured temperature. DAG content was lower in CIE than EIE sample. Besides, each EIE or CIE products were compared with blends, where higher SFC, longer induction time was observed in the blends. Oxidative stability was measured based on Rancimat and peroxide value (PV) where EIE sample showed longer induction time and lower PV compared to CIE sample. Further, EIE sample was selected for oxidation studies and kept at 60 °C for 22 d after the addition of antioxidants (EGCG, rosemary) where induction time was significantly increased compared to control. EGCG containing sample showed longer induction time and lower PV compared to rosemary containing sample. Practical Application: This research can show the application of SO in the bakery industry, which is a byproduct of shea butter production. There is very limited published information about SO application in bakery food. In addition, it could be useful for industrial application to compare the physicochemical properties of enzymatic interesterification compared to chemical interesterification.  相似文献   

18.
新疆薄皮核桃的化学组成及特性的研究   总被引:1,自引:0,他引:1  
核桃作为一种健康营养的食品,对其化学组成及特性的研究显得尤为重要。为了更有利于新疆薄皮核桃的开发和利用,采用国标方法测定核桃的化学组成,采用气相色谱法测定脂肪酸组成,采用液相色谱法测定氨基酸组成。结果显示:核桃仁蛋白质含量高达17.66%,粗脂肪含量达60.84%;核桃脱脂粉的氮溶解指数(NSI)为2.74%;核桃仁油含较高的多不饱和脂肪酸,总含量为75.05%,其中亚油酸含量高达64.03%,亚麻酸达11.02%。赖氨酸(Lys)是核桃蛋白质氨基酸的第一限制必需氨基酸。核桃蛋白质中含有较多的谷氨酸和精氨酸,含量均超过其它几种氨基酸。除了蛋氨酸(Met)、苯丙氨酸(Phe)和赖氨酸(Lys)含量低于FAO/WHO推荐给2~5岁幼儿的标准,其它几种必需氨基酸均高于标准值。  相似文献   

19.
Lipase-catalysed interesterification was performed to produce low-trans spreadable fat (LTSF) with anhydrous butterfat (ABF), flaxseed oil (FSO), and palm stearin (PS) using biocatalysts (Lipozyme RM IM and Novozym SP435). The reaction was carried out for 24 h at 60 °C in a shaking water bath (180 rpm). Seven substrate blends for the production of LTSF were prepared: 12:6:2, 10:6:4, 9:6:6, 8:6:6, 6:6:8, 6:6:9, and 4:6:10 (ABF/PS/FSO, by weight). After 24-h interesterification, decreased saturated fatty acid (SFA) contents in LTSFs were observed with ranges from 67% to 41%. LTSFs exhibited low atherogenic index (AI) with ranges from 2.8 to 0.8, compared with 3.3–4.7 AI of butter fat. Equivalent carbon number (ECN) 42–46 in the newly produced triacylglycerol (TAG) increased according to rearrangement of FAs on TAG backbone. The α-linolenic acid contents (mol%) of each LTSF were 5.6% (12:6:2), 10.7% (10:6:4), 15.1% (9:6:6), 15.8% (8:6:6), 20.8% (6:6:8), 22.4% (6:6:9) and 26% (4:6:10). The trans fatty acids in the LTSFs was not more than 2%. Melting point ranges of LTSF were from 37 (9:6:6) to 32 °C (4:6:10).  相似文献   

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