Relationship between slip melting point and pulsed NMR data of palm kernel oil

A quantitative relationship between slip melting point (SMP) of palm kernel oil and pulsed nuclear magnetic resonance (NMR) data was established. Regression analysis on the SMP and solid fat content (SFC) data by NMR afforded the following relationship: SMP (°C) = 0.03278 X (SFC 10) + 0.1458 X (SFC 20) + 19.1738 where SFC 10 was the solid fat content (%) at 10°C and SFC 20 was the solid fat content (%) at 20°C. The coefficient of multiple correlation was 0.87871. The equation was tested with 12 samples of crude and refined palm kernel oil. SMPs as determined indirectly by NMR correlated well with the conventional open capillary tube results (r = 0.99998). The maximum difference observed was 0.3°C. The correlation can be applied usefully for quality control.     

Factors affecting cloud point analysis of palm oleins

Some of the factors affecting cloud point determination of palm oleins are described. These are the type of container used, method of stirring, rate of stirring and bath temperature. The repeatability and reproducibility standard deviations of the method are determined from collaborative trials. Recommendations for the test are made to reduce the large variations among laboratories.     

Polymorphism of palm oil and palm oil products

Palm oil, palm stearin, hydrogenated palm oil (IV 27.5) and hydrogenated palm olein (IV 28) were crystallized at 5°C, temperature cycled between 5 and 20°C, and kept isothermally at 5°C for 36 days. The polymorphic state of the fats was monitored by X-ray diffraction analysis. Soft laser scanning of X-ray films was used to establish the increase inβ crystal content. Palm stearin was least stable in theβ′ form, followed by palm oil. The hydrogenated oils were very stable in theβ′ form. Differential scanning calorimeter (DSC) analysis was used to complement the X-ray data.     

Determination of slip melting point in palm oil blends by partial least squares and principal component regression modeling of FTIR spectroscopic data

The determination of slip melting point (SMP) in refined, bleached, and deodorized palm oil is a common and regular requirement in the manufacture of this oil. An FTIR spectrometer in the mid-IR wavelength region (4000-750 cm⁻¹) can provide the basis for a suitable on-line and off-line quantitative analytical methodology if used with a suitable calibration model. In this study, by using data from selected regions, the calibration models, including principal component regression and partial least squares regression, have been examined and evaluated for efficacy in determining SMP directly in palm oil blends. Results indicate that orthogonal models using selected wavelength data offer superior predictive performance.     

Crystallisation and melting behaviour of palm kernel oil and related products by differential scanning calorimetry

Lauric oils are valuable sources for oils suitable for various food applications. They are particularly useful as cocoa butter substitutes for which steep solid fat content profiles are required. Palm kernel oil is one such fat, which upon fractionation and/or hydro‐genation provides a variety of oil fractions with different oil composition and properties. The stearins have excellent properties for confectionery fats, while the oleins can be further hydrogenated to improve their properties. This paper gives an overview of the properties of products of palm kernel oil, produced from fractionation and hydrogena‐tion. The melting and crystallisation properties from differential scanning calorimetry studies are discussed in relation to the triacylglycerols of the oils.     

影响E玻璃熔制质量的因素

在无碱玻璃纤维池窑拉丝生产过程中,从原料选择、配合料制备、窑炉熔化到纤维成型,影响拉丝作业的因素有很多,笔者根据本厂玻纤池窑生产的实践经验,就有关因素作一简单介绍,与同行交流。     

Synthesis of civetone from palm oil products

Metathesis of ethyl oleate, catalyzed by WCl₆ and SnMe₄, provided diethyl 9-octadecenedioate (the desired starting material for the synthesis of civetone) in 99% yield. Dieckmann condensation of diethyl 9-octadecenedioate gave 2-ethoxycarbonyl-9-cycloheptadecenone (63% yield), the hydrolysis-decarboxylation reaction of which yielded civetone (93%). Identification of all products was by¹H nuclear magnetic resonance, infrared and mass spectroscopic data. This is the first report of the synthesis of civetone from palm oil-derived products.     

Palm oil and palm kernel oil in food products

Cocoa butter equivalent (CBE) formulation, especially the compatibility of palm oil based CBE with cocoa butter, is of special interest to chocolate manufacturers. Traditionally palm oil is fractionated to obtain high-melting stearin and olein with a clear point of around 25 C, the latter serving as cooking oil. Recently, palm oil has been fractionated to recover an intermediate fraction known as palm mid-fraction (PMF), which is suitable for CBE formulations. Generally, production of PMF is based on a three-step procedure. However, a dry fractionation system, which includes selective crystallization and removal of liquid olein by means of a hydraulic press, has been developed. Iodine value, solid content (SFI) at different temperatures, cooling curves (Shukoff 0°) and triglyceride/fatty acid composition determination confirmed effectiveness of the procedure followed. A direct relationship between yield, quality of PMF and crystallization temperature during fractionation has been achieved. Yield of 60% for olein of IV 64–67 has been achieved. Yield of 30% for PMF of IV 36–38 and 10% for high melting stearin of IV of 20–22 are also being achieved. High-melting stearin may be used in oleochemical applications, soaps, food emulsifiers and other industrial applications such as lubricating oil. Olein fraction, especially after flash hydrogenation thereby reducing the IV to 62/64, has excellent frying and cooking oil characteristics. Palm olein is also suitable as dietary fat and in infant formulation. Studies on interesterification of high-melting stearin with olein showed possibilities to formulate hardstocks for margarine and spread formulations, even without using hydrogenated fat components. Palm kernel and coconut fats or fractions or derived products are used for confectionery products as partial CB replacers and as ice cream fats and coatings. Coconut oil also serves as a starting material for the production of medium-chain triglycerides.     

Differential scanning calorimetry of palm kernel oil products

A variety of fractionated and hydrogenated fats were derived from a commercial sample of Malayan palm kernel oil. These were studied by differential scanning calorimetry at different rates of cooling and heating. The resulting thermograms, and latent heats derived from them, were compared with one another and with underlying triglyceride compositions. This enabled three potential interpretations of the thermograms to be compared. The shapes of the cooling thermograms were most complicated, and dependent on the influence of the spontaneous crystallization, which followed supercooling when cooling rates of 8 C per min or more were imposed. Triglyceride composition had a less significant influence on the shapes of the curves, while polymorphism had almost no influence. The cooling thermograms, thus, are more complicated than heating thermograms, a conclusion at variance with one expressed elsewhere. The dynamic nature of the differential scanning calorimetry method is highlighted by the results of this work, and it is concluded that there are dangers in conducting differential scanning calorimetry studies at a single rate of temperature change.     

Effect of enzymatic transesterification on the melting points of palm stearin-sunflower oil mixtures

Transesterification with lipases may be used to convert mixtures of fats to plastic fats, making them more suitable for use in edible products. In our study, 1,3-specific (Aspergillus niger, Mucor javanicus, Rhizomucor miehei, Rhizopus javanicus, and Rhizopus niveus) and nonspecific (Pseudomonas sp. and Candida rugosa) lipases were used to transesterify mixtures of palm stearin and sunflower oil (PS-SO) at a 40:60 ratio in a solvent-free medium. The transesterified mixtures of PS-SO were analyzed for their percentage free fatty acids (FFA), degree and rate of transesterification, solid fat content, slip melting point (SMP), and melting characteristics by differential scanning calorimetry. Results indicated that Pseudomonas sp. lipase produced the highest degree (77.3%) and rate (50.0 h⁻¹) of transesterification, followed by R. miehei lipase at 32.7% and 27.1 h⁻¹, respectively. The highest percentage FFA liberated was also in the reaction mixtures catalyzed by Pseudomonas sp. (2.5%) lipase and R. miehei (2.4%). Pseudomonas-catalyzed mixtures produced the biggest drop in SMP (13.5°C) and showed complete melting at below body temperature. All results indicated conversion of the PS-SO mixtures to a more fluid product. The findings also suggest that the specificity of lipases may not play a significant role in lowering the melting point of the PS-SO mixtures.     

通过一步法乙氧基化反应降低棕榈硬脂的熔点

探索用Mg-AI基复合物催化剂催化环氧乙烷（EO）嵌入棕榈硬脂实现一步法乙氧基化。通过红外光谱及乳化力测定证明发生了预期反应。实验考察了催化剂的种类及反应温度的影响,并探讨了不同原料配比反应产物熔点的影响．得出n（EO）：n（棕榈硬脂）=6：1条件下产物熔点最低为19．8℃。该合成路线简便快捷,不生成副产物．是原子经济性绿色化学反应。     

DSC study on the melting properties of palm oil, sunflower oil, and palm kernel olein blends before and after chemical interesterification

Changes in DSC melting properties of palm oil (PO), sunflower oil (SFO), palm kernel olein (PKOo), and their belends in various ratios were studied by using a combination of blending, and chemical interesterification (CIE) techniques and determining total melting (ΔH _f ) and partial melting (ΔH _i°C ) enthalpies. Blending and CIE significantly modified the DSC melting properties of the PO/SFO/PKOo blends. PO and blends containing substantial amounts of PO and PKOo experienced an increase in their DSC ΔH _f and ΔH _i°C following CIE. The DSC ΔH _f and ΔH _i°C of PKOo, blends of PO/SFO at 1∶1 and 1∶3 ratios, and all blends of PKOo/SFO significantly decreased after CIE. The DSC ΔH _f and ΔH _i°C of SFO changed little following CIE. Randomization of FA distribution within and among TAG molecules of PO and PKOo led to modification in TAG composition of the PO/PKOo blends and improved miscibility between the two fats and consequently diminished the eutectic interaction that occurred between PO and PKOo.     

Comparative nutritional study of enzymatically and chemically interesterified palm oil products

A comparative evaluation of the nutritional value of palm oil, which was interesterified by lipozyme and by chemical catalysis, has been done with albino rats (Charles Foster strain). The two interesterified fats have identical coefficients of digestibility, and rats fed the two fats exhibit similar patterns of growth response and food efficiency ratio. The total lipid and total cholesterol levels in serum of rats of the two interesterified fats are nearly the same, but there is a significant difference in free cholesterol level. The lipozyme-catalyzed product creates a higher level of free cholesterol. Liver lipids of rats are identical in amount for the two groups, but the total cholesterol level of the lipozyme-catalyzed group is significantly less than the chemically catalyzed group. The positional distribution of fatty acids differs between the two interesterified products. The nutritional attributes of interesterified oils can vary depending on the specificity of the catalyst employed.     

Composition and thermal profile of crude palm oil and its products

Gas-liquid chromatography and high-performance liquid chromatography (HPLC) were used to determine fatty acids and triglyceride (TG) compositions of crude palm oil (CPO), refined, bleached, and deodorized (RBD) palm oil, RBD palm olein, and RBD palm stearin, while their thermal profiles were analyzed by differential scanning calorimeter (DSC). The HPLC chromatograms showed that the TG composition of CPO and RBD palm oil were quite similar. The results showed that CPO, RBD palm oil, RBD olein, and superolein consist mainly of monosaturated and disaturated TG while RBD palm stearin consists mainly of disaturated and trisaturated TG. In DSC cooling thermograms the peaks of triunsaturated, monosaturated and disaturated TG were found at the range of −48.62 to −60.36, −25.89 to −29.19, and −11.22 to −1.69°C, respectively, while trisaturated TG were found between 13.72 and 27.64°C. The heating thermograms of CPO indicated the presence of polymorphs β₂′, α, β₂′, and β₁. The peak of CPO was found at 4.78°C. However, after refining, the peak shifted to 6.25°C and became smaller but more apparent as indicated by RBD palm oil thermograms. The heating and cooling thermograms of the RBD palm stearin were characterized by a sharp, high-melting point (high-T) peak temperature and a short and wide low-melting point (low-T) peak temperature, indicating the presence of occluded olein. However, for RBD palm olein, there was only an exothermic low-T peak temperature. The DSC thermograms expressed the thermal behavior of various palm oil and its products quite well, and the profiles can be used as guidelines for fractionation of CPO or RBD palm oil.     

Factors affecting the nutritional quality of soya products

The nutritional quality of soya products is determined not only by the quantity and availability of the amino acids which make up the protein of such products, but is also markedly affected by the processing conditions which are employed in their manufacture. The most important factor in this regard is the application of some form of heat treatment which serves to inactivate a number of naturally occurring constituents of the soybean. Although non-toxic in the truest sense of the word, these are substances which can nevertheless elicit adverse physiological responses in animals, and, unless destroyed, can detract from the full nutritional potential of soya protein. The best known and certainly the most studied of these factors are the inhibitors of trypsin and chymotrypsin, enzymes which play a key role in the digestion of proteins in animals. These will be discussed with respect to their possible model of action in vivo, and an attempt will be made to evaluate their nutritional significance in man. Also present in soybeans are several other heat-labile components whose physiological significance is less well understood. These include the phytohemagglutinins (lectins), goitrogens, antivitamins and phytates. Less sensitive to the destruction effects of heat are a number of factors which are capable of producing a wide variety of physiological responses in animals and include saponins, estrogens, oligosaccharides and allergens. Although present in readily detectable quantities, their effect on the nutritional quality of soya protein is questionable. Not to be overlooked is the fact that harsh processing conditions such as excessive heat treatment or extraction under alkaline conditions may lead to the destruction of economic importance at the present time, brief consideration will be given to the possible effects of germination and fermentation on the nutritive quality of the protein resulting from such treatments.     

Factors affecting the composition of canadian oil seeds

Importance of climate, plant breeding, and economics to production of oil seeds in Canada is considered. The influence of temperature and rainfall on the oil content and fatty acid composition of linseed and rapeseed is discussed. Major changes in the fatty acid composition of rapeseed oil can be effected by modern techniques in plant breeding and selection, i.e. erucic acid content can be reduced from approximately 40% to 0. The impact on the oil meal market of continued selection for high oil in crops and varieties is discussed.     

Factors affecting the electrical resistivity of soybean oil

The electrical resistivity of soybean oil that had been purified to remove polar constituents was determined, and the effect of measuring conditions and the addition of polar constituents (free fatty acids, phospholipids, monoglyceride, α-to-copherol, β-sitosterol, β-carotene, peroxides, and water) on resistivity was investigated. For reproducible resistivity measurements, voltages in excess of 50 volts and charging times greater than 120 s were necessary. As temperature was increased linearly, the resistivity of the oil decreased logarithmically. For making comparisons, a temperature of 24°C, a potential of 50 volts, and 120 s charging times were chosen. All polar constituents decreased the resistivity of the purified soybean oil, but water, phospholipids, and monoglycerides had the greatest effects. Water increased the resistivity-lowering effects of all other constituents except for free fatty acids, which were affected by water only slightly. The synergistic effect of water was much greater for phospholipids and monoglyceride than for other constituents.     

Effects of refining on chemical and physical properties of palm oil products

Some chemical changes in the composition and physical properties of palm oil products are discussed. The effects of bleaching and deodorization on oxidative properties and possible isomerization and interesterification of the fatty acids were indicated from laboratory refining experiments. Investigation of commercial samples of refined palm oil products showed that the conjugated dienes and trienes formed are minimal, indicating the use of good quality raw materials and mild processing conditions. Very little isomerization occurred in commercial refined products as indicated from the level oftrans acids, and changes in the POP to PPO triglycerides due to possible interesterification were insignificant. Changes in physical properties were inevitable due to the removal of free fatty acids and diglycerides and to minor impurities.