棕榈油与棕榈油中熔点分提产物相容性及结晶形态研究

利用等温相图和偏光显微技术研究了棕榈油(PO)与棕榈油中熔点分提产物(PMF)在混合体系中的相容性及晶体形态.结果表明:PO与PMF混合体系在0～40℃相容性良好,仅在桌些温度范围内存在轻微的共晶/偏晶现象;结晶形态研究表明甘三酯组成对混合体系晶形有显著影响.     

基料油相容性及乳化剂对人造奶油结晶行为的影响

利用低场脉冲核磁共振仪和偏振光显微镜、粉末X-射线衍射等分析手段分别对棕榈油基混合体系的相容性以及乳化剂种类对以此为基料油制备的人造奶油结晶行为的影响进行了研究。结果表明:经混料回归设计的1号(POs∶PMF∶PKO,0.8∶0.1∶0.1)、4号(POs∶PMF∶PKO,0.45∶0.45∶0.1)配方相容性最好,6号(POs∶PMF∶PKO,0.1∶0.45∶0.45)配方出现严重共晶现象,且在20℃左右共晶最为严重;向1号配方添加丙二醇酯及向4号配方添加聚甘油酯所得产品b和c均为β’晶型;产品c的晶体形态最易受温度波动的影响。     

巧克力涂层基料油的理化性质及其相容性研究

选用棕榈油中间分提物(PMF)、全氢化棕榈仁液油(HPKOL)、可可脂(CB)作为巧克力涂层的基料油,对其理化性质及其相容性进行分析。结果表明,当两相体系PMF-HPKOL中PMF含量在30%以下时,共晶现象较弱。PMF和HPKOL混合可以作为涂层油脂配方,用于开发无反式脂肪酸巧克力涂层。添加可可脂会导致三相体系(PMF-HPKOL-CB)严重的共晶现象,因此在代可可脂涂层配方中不宜再添加可可脂。     

棕榈油硬脂和棕榈油中间分提物性能及相容性研究

为改善油脂可塑性和口溶性,及为开发以棕榈油产品为主要原料专用油脂产品提供理论依据,研究棕榈油硬脂(PSt)、棕榈油中间分提物(PMF)两者间相容性。测定二元混合体系固体脂肪含量(SFC)值,并通过计算其理论值与实测值之间差值△SFC,结合T–△SFC曲线、二元等温曲线等直观分析,结果表明:PSt与PMF混合物在25℃、PSt含量为30%～50%时,二者间偏晶现象严重;而在35℃～50℃时,二者间共晶现象较为严重;在0℃～10℃和30℃～35℃范围内,二者间具有较好相容性。     

巧克力涂层基料油理化性质和相容性的研究北大核心CSCD

选用棕榈油中间分提物(PMF)和氢化棕榈油(HPO)作为巧克力涂层的基料油,对两种油脂的理化性质进行了分析。同时,通过等温曲线和实测固体脂肪含量与理论固体脂肪含量的偏差曲线分析PMF和HPO的相容性。实验结果表明:PMF和HPO在脂肪酸和甘三酯的组成上相似,PMF和HPO具有良好的相容性,PMF和HPO按照比例3∶7(质量比)混合可以作为巧克力涂层基料油配方。     

巧克力涂层基料油理化性质和相容性的研究

选用棕榈油中间分提物(PMF)和氢化棕榈油(HPO)作为巧克力涂层的基料油,对两种油脂的理化性质进行了分析。同时,通过等温曲线和实测固体脂肪含量与理论固体脂肪含量的偏差曲线分析PMF和HPO的相容性。实验结果表明:PMF和HPO在脂肪酸和甘三酯的组成上相似,PMF和HPO具有良好的相容性,PMF和HPO按照比例3∶7(质量比)混合可以作为巧克力涂层基料油配方。     

棕榈油部分替代猪板油及其相容性研究

选用棕榈液油(OL)与棕榈硬脂(ST)部分替代猪板油,对其理化性质及相容性进行分析,并使用欧式距离法确定复配棕榈油替代猪板油配方。结果表明:棕榈油替代猪板油在理化性质、健康方面具有明显的优势;棕榈油与猪板油之间的相容性与温度和质量分数有密切的关系,整体来看,二元体系低温下易出现偏晶现象,高温下易出现共晶现象,温度越低,相容性越差,温度在35~40℃之间时,相容性较好;通过相似度比较得出,质量分数为30%的ST和70%的OL复配时,可以作为部分替代猪板油的配方。     

猪油与3种植物油二元混合体系相容性研究

油脂相容性是影响调和油脂品质及稳定性的重要因素,本文通过测定猪油(LO)、菜籽油(RO)、大豆油(SBO)和椰子油(CNO)的基本理化性质,利用碘值、固体脂肪含量等温曲线(SFC-T)及偏差曲线(ΔSFC-T)对LO与RO/SBO/CNO的二元混合体系的不饱和度及相容性进行分析研究。结果表明:RO/SBO可以提高其与LO混合油脂的不饱和度,且与两种植物油脂质量分数呈正相关性,CNO则相反;不同比例的LO与RO/SBO/CNO混合油脂在5、10℃出现轻微共晶现象,在15~50℃出现偏晶现象;3种植物油脂中RO/SBO与LO相容性较好,CNO较差;混合油脂比例分别为1∶9(RO∶LO)、1∶9/2∶8(SBO∶LO)及1∶9(CNO∶LO)时,ΔSFC值在-1.5%~2%范围内,油脂相容性最佳。     

椰子油与棕榈硬脂油物理混合及其结构脂熔融特性的比较研究

油脂的相容性和非等温结晶性质对油脂的口感品质有重要影响。为了拓宽椰子油和棕榈油的应用范围,开发以其为主要原料的专用油脂产品,本文通过GC-MS测得椰子油和棕榈硬脂油不同混合比例的总脂肪酸和Sn-2位脂肪酸组成,研究了脂肪酸组成与熔融特性的相关性,再利用脉冲核磁共振仪研究了椰子油和棕榈油的相容性,并用差式扫描量热仪对二者按一定比例混合的复配体系和酶法制备结构脂的非等温结晶行为进行研究。结果表明:不同比例酶法制备结构脂中Sn-2位的月桂酸含量(12.35~46.72%)明显高于物理混合油(5.86~30.75%)。该复配体系整体上存在一定程度的共晶现象,在较高温度(25~45℃)时,相容性较好。在非等温结晶过程中,在同一降温速率条件下,随着椰子油比例的增加,2倍链长的β′型晶体,转变为低熔点的3倍链长β′晶型。     

棕榈仁油与五种油脂相容性的研究

利用等温相图,研究了棕榈仁油与5种常见人造奶油基料油———棕榈油、棕榈油硬脂、棕榈油软脂、氢化棕榈油和牛脂之间的二元相容性。结果表明,棕榈仁油与棕榈油系列油混合物在20~25℃内出现严重的共晶现象,与牛脂在10℃内出现偏晶现象,在20~25℃出现严重的共晶现象。     

Physicochemical properties and crystallisation behaviour of bakery shortening produced from stearin fraction of palm-based diacyglycerol blended with various vegetable oils

The stearin fraction of palm-based diacylglycerol (PDAGS) was produced from dry fractionation of palm-based diacylglycerol (PDAG). Bakery shortening blends were produced by mixing PDAGS with either palm mid fraction, PMF (PDAGS/PMF), palm olein, POL(PDAGS/POL) or sunflower oil, SFO (PDAGS/SFO) at PDAGS molar fraction of X_PDAGS = 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%. The physicochemical results obtained indicated that C16:0 and C18:1 were the dominant fatty acids for PDAGS/PMF and PDAGS/POL, while C18:1 and C18:2 were dominant in the PDAGS/SFO mixtures. SMP and SFC of the PDAGS were reduced with the addition of PMF, POL and SFO. Binary mixtures of PDAGS/PMF had better structural compatibility and full miscibility with each other. PDAGS/PMF and PDAGS/SFO crystallised in β′+β polymorphs in the presence of 0.4–0.5% PDAGS while PDAGS/POL resulted in β polymorphs crystal. The results gave indication that PDAGS: PMF at 50%:50% and 60%:40% (w/w) were the most suitable fat blend to be used as bakery shortening.     

Evaluation of high oleic-high stearic sunflower hard stearins for cocoa butter equivalent formulation

Cocoa butter equivalents (CBEs) are produced from vegetable fats by blending palm mid fraction (PMF) and tropical butters coming from shea, mango kernel or kokum fat. In this regard, high oleic-high stearic (HOHS) sunflower hard stearins from solvent fractionation can be used in CBE production since their compositions and physical properties are similar to those found in the above-mentioned tropical butters. In this work, three sunflower hard stearins (SHS) ranging from 65% to 95% of disaturated triacylglycerols and a shea stearin (used as reference) were blended with PMF to evaluate their potential use in CBEs formulation. Isosolid phase diagrams of mixtures of PMF/SHS showed eutectic formation for SHS 65 and SHS 80, but monotectic behaviour with softening effect for SHS 95. Three CBEs from SHS and shea stearin were formulated according to phase behaviour diagrams and solid fat content data at 25 °C. Isosolid phase diagrams of mixtures of these CBEs with cocoa butter showed no eutectic behaviour. Therefore, CBEs elaborated from SHS exhibited full compatibility with cocoa butter.     

Interactions of milk fat and milk fat fractions with confectionery fats

The objectives of this study were to provide a better understanding of the effects of triacylglycerol (TAG) and non-TAG components (minor lipids) of milk fat on phase and crystallization behavior of binary mixtures of palm kernel oil (PKO) and the physical properties of corresponding compound coatings. Binary mixtures of a fractionated PKO with the different milk fats were examined for melting profiles, crystallization kinetics, and crystalline microstructures, and polymorphic changes during storage. Compound coatings were made with equivalent binary fat mixtures and measured for hardness and bloom formation. Milk fat and milk fat fractions affected crystallization rates of fractionated PKO, depending on the melting point of the fat. High-melting components resulted in more rapid crystallization, whereas the original milk fat and low-melting components inhibited crystallization. The crystal structure (e.g., number, size, shape) of the PKO crystals was influenced significantly by the addition of milk fat fractions and was influenced by the presence or absence of the minor lipids in milk fat. Milk fat and milk fat fractions had a softening effect on fractionated PKO, which was apparent in the binary mixtures as well as the compound coatings. In general, as the solid fat content (at 25 degrees C) of the binary mixtures increased, the hardness of the respective coatings increased. This also was related to an increased rate of bloom formation during storage.     

Physico-chemical properties of various palm-based diacylglycerol oils in comparison with their corresponding palm-based oils

Palm-based diacylglycerol (P-DAG) oils were produced through enzymatic glycerolysis of palm kernel oil (PKO), palm oil (PO), palm olein (POL), palm mid fraction (PMF) and palm stearin (PS). High purity DAG (83–90%, w/w) was obtained and compared to palm-based oils (P-oil) had significantly (P < 0.05) different fatty acid composition (FAC), iodine value (IV) and slip melting point (SMP). Solid fat content (SFC) profiles of P-DAG oils as compared to P-oils had less steep curves with lower SFC at low temperature range (5–10 °C) and the higher complete melting temperatures. Also, P-DAG oils in contrast with P-oils showed endothermic as well as exothermic peaks with higher transition temperatures and significantly (P < 0.05) higher crystallisation onsets, heats of fusion, and heats of crystallisation. Crystal forms for P-DAG oils were mostly in the β form.     

Effects of variation in the palm stearin: Palm olein ratio on the crystallisation of a low-trans shortening

Changes in the rheological properties during crystallisation and in the crystal size and morphology of blends containing rapeseed oil with varying percentages of palm stearin (POs) and palm olein (POf) have been studied. The crystals formed from all three blends were studied by confocal laser scanning microscopy, light microscopy and environmental scanning electron microscopy, which revealed the development of clusters of 3–5 individual elementary “spherulites” in the early stages of crystallisation. The saturated triacylglycerol content of the solid crystals separated at the onset of crystallisation was much greater than that in the total fat. Fat blends with a higher content of palm stearin had a more rapid nucleation rate when observed by light microscopy, and this caused an earlier change in the rheological properties of the fat during crystallisation. Using a low torque amplitude (0.005 Pa, which was within the linear viscoelastic region of all samples studied) and a frequency of 1 Hz, the viscoelastic properties of melted fat during cooling were studied. All samples, prior to crystallisation, showed weak viscoelastic liquid behaviour (G″, loss modulus >G′, storage modulus). After crystallisation, a more “solid like” behaviour was observed (G′ similar to or greater than G″). The blend having the highest concentration of POs was found to have the earliest onset of crystallisation (27% w/w POs; 12 mins, 22% w/w POs; 13.5 mins, 17% w/w POs, 15 mins, respectively). However, there were no significant differences in the time to the point when G′ became greater than G′ among the three blends.     

Distinguishing lard from other animal fats in admixtures of some vegetable oils using liquid chromatographic data coupled with multivariate data analysis

Detection of animal fat adulterants in vegetable oils is of great importance from commercial and health perspectives. Distinguishable identification of lard contamination in some vegetable oils has been attempted in this study. Vegetable oils, namely palm oil (PO), palm kernel oil (PKO), and canola oil (CLO), were spiked with different proportions of animal fats, such as lard (GLD), beef tallow (BT), and chicken fat (CF). High-performance liquid chromatographic (HPLC) analyses were performed to monitor the triacylglycerol (TAG) compositional changes in the oil samples before and after adulteration. The results showed that qualitative determination of lard contamination in PKO was possible by a visual comparison of TAG profiles of PKO adulterated with different animal fats with those of the animal fats. This approach was not useful for PO and CLO. However, by subjecting liquid chromatographic data to multivariate procedures, distinguishable grouping of lard-contaminated samples was achieved for all three oils.     

VISCOELASTIC PROPERTIES OF TABLE MARGARINE PREPARED FROM LIPASE-CATALYZED TRANSESTERIFIED MIXTURES OF PALM STEARIN AND PALM KERNEL OLEIN

A controlled-stress rheometer was used to evaluate dynamic viscoelastic (VE) performance of an experimental table margarine prepared from a transesterified palm stearin (PS):palm kernel olein (PKO) mixture (40:60 ratio) using Rhizomucor miehei lipase as the biocatalyst. Comparison was made using a commercial table margarine made of palm oil and palm kernel oil. The experiments were carried out over a period of three months with the margarines kept at 20 and     

核桃油与棕榈硬脂复配体系在涂抹脂基料油中的应用

对棕榈硬脂与核桃油复配体系的相容性及结晶性质变化进行探究,考察复配体系在涂抹脂基料油中的应用。结果表明,当核桃油含量达到20%以上时,复配体系的固体脂肪含量(Solid Fat Content,SFC)变化趋势符合涂抹脂的最佳SFC曲线特征,适合用作涂抹脂基料油;在温度高于33.3℃时,核桃油与棕榈硬脂在复配比例(1∶9、2∶8、3∶7、4∶6)下可以完全相容;在核桃油比例达到3∶7以上时,复配体系的屈服值符合涂抹脂的最佳屈服值范围;在温度低于30℃时,棕榈硬脂及复配体系具有较强的晶体网络结构,能在运输和贮藏过程中维持稳定的形态,在接近体温时也能快速熔化,产生涂抹脂类似的口感,复配体系中晶体以β′晶型为主。该结果为棕榈硬脂及核桃油复配体系在涂抹脂中的应用奠定基础。     

茶多酚棕榈酸酯在棕榈油中的抗冻应用

在10度和14度棕榈油中添加50、100、200mg/kg的茶多酚棕榈酸酯（TP）,通过检测5℃或8℃条件下的抗冻时间、完全结冻样品在30℃条件下的解冻现象,结果发现：添加50mg/kg的样品,抗冻时间即可成倍延长,含量越高,抗冻时间越长;添加TP后解冻性并无显著差异;14度油中加入一定比例TP后,抗冻性可达到10度类似效果。