Palm Mid Fraction Research Articles

Effects of hydrophobic emulsifier additives on crystallization behavior of palm mid fraction in oil‐in‐water emulsion

AbstractUltrasonic velocity measurements and X‐ray diffraction were employed to monitor the crystallization behavior of palm mid fraction (PMF) in oil‐in‐water emulsions (20 vol%). Three hydrophobic emulsifiers—sucrose oligoesters (SOE) containing palmitic acid (P‐170) and stearic acid (S‐170) moieties and a polyglycerine ester (DAS‐750) containing a stearic acid moiety—were added to PMF in an attempt to increase the rate and extent of crystallization of PMF, which are otherwise suppressed owing to emulsification of the oil phase into many droplets. The results revealed that the hydrophobic emulsifiers accelerate the nucleation of PMF in the emulsion system, while retarding the rate of crystal growth. As a results, the crystallization temperature (Tc) of PMF increased with increasing concentrations of the hydrophobic emulsifiers. The effects of the three additives were different; in particular the addition of DAS‐750 remarkably enhanced crystallization at low concentrations. By adding the emulsifiers at higher concentrations, the polymorphic behavior of PMF crystallization was also modified to different degrees, depending on the type of emulsifier. With addition of SOE, PMF crystallized predominantly in the β′ form; with addition of DAS‐750, the extent of β′ nucleation was reduced by comparison with that observed with SOE. The results were explained in terms of adsorption of the hydrophobic emulsifier additives at the oil‐water interface, which provides a template for acceleration of surface heterogeneous nucleation of PMF in the emulsion system.

Preparation of sharp‐melting hard palm midfraction and its use as hard butter in chocolate

AbstractPreparation of hard palm midfractions (PMF) and its use as a cocoa butter equivalent ingredient were studied. Hard PMF is obtained by multistep fractionation of palm oil involving dry fractionation (DF) and/or solvent fractionation (SF), usually using hexane or acetone. From our experience, in acetone, a polar solvent, symmetrical 1,3‐disaturated triacylglycerols tend to selectively crystallize more than nonsymmetrical 1,2‐ or 2,3‐disaturated triacylglycerols, making it suitable for obtaining the solid midfraction. Unfortunately, triacylglycerols are very soluble in hexane, and temperatures at least 15 degrees lower than those required for acetone must be used for equivalent crystal yields. On the other hand, DF is a less expensive and safer process. Thus, multistep fractionation combining DF and SF using acetone was developed to achieve sufficient removal of high‐melting components, and further enrichment of 1,3‐dipalmitoyl‐2‐oleoylglycerol and the hard PMF was obtained by triple‐step fractionation of palm olein or double‐step fractionation of soft PMF. Compared to conventional hard PMF, this hard PMF had a steeper melting curve and better snapping and sharp‐melting qualities when used in chocolate. Heat resistance of the hard PMF chocolate was similar to the conventional hard PMF chocolate, and its bloom resistance could be improved by adding polyglycerol fatty acid esters.

Use of palm mid-fraction in dark chocolate as base filling centre at different storage temperatures

Dark chocolates filled with palm mid-fraction (PMF) were stored at different temperatures to evaluate the physical and chemical changes. Storage at low temperature (18°C) reduces the PMF migration to negligible extent. Higher storage temperatures (30 and 35°C) increased the PMF migration from the filling centre into the chocolate coating. As a consequence of fat migration, fatty acid composition, triglyceride composition, hardness, solid fat content, melting point and polymorphic structure changed, leading to bloom formation, which started by fat migration and was influenced by recrystallization tendency within the chocolate coating.

Characteristics of Red Palm Oil, a Carotene- and Vitamin E–rich Refined Oil for Food Uses

A novel process involving pretreatment of crude palm oil, followed by deacidification and deodorization using molecular distillation, can be used to produce a carotene-rich refined edible palm oil. the product is a refined red palm oil that meets standard refined edible oil specifications and retains up to 80% of the carotene and vitamin E originally present in the crude palm oil. the oil contains no less than 500 ppm carotene, 90% of which is present as α- and β-carotene. the vitamin E content is about 800 ppm, 70% of it in the form of tocotrienols (mainly as α-, β-, and γ-tocotrienols). Other valuable minor components present in this oil are ubiquinones and phytosterols. the process is also applicable for the commercial production of other natural vitamin-rich palm fractions, such as stearin, olein, and palm mid-fraction. Such products are currently available and can be used in various food applications, both as cooking media and as ingredients that enhance the appearance and nutritional value of foods.

Use of Palm Mid-Fraction in White Chocolate Formulation

Samples of two types of palm mid-fraction (PMF I, a commercial sample and PMF II, from a laboratory-scale acetone fractionation of PMF I) and a Malaysian deodorised cocoa butter sample were used as the main components in the fat phase for white chocolate formulation. The monounsaturated triacylglycerol contents of these fats were 853, 899 and 903 g kg -1 , respectively. All the fats had free fatty acid contents of less than 10 g kg -1 and melting points in the range of 34.0-34.5°C. The solid fat content profiles for the three fats were very steep. Differential scanning calorimeter analyses showed that all the fats had two melting peaks, T1 and T2. Results of the study showed that the tempering time to produce a well-tempered chocolate using PMF I was longer than that using PMF II, whereas, the time to produce a well-tempered cocoa butter chocolate increased with increase in the tempering temperature. Chocolates made with PMF I and II were well tempered between 17 and 19°C and with cocoa butter at 23°C. Thermal analyses, carried out on the chocolate showed that PMF I and II produced three melting peaks, T1, T2' and T2 whereas most of the cocoa butter chocolates exhibited only one melting peak, T2. Storage studies showed that most of the chocolates had good bloom resistance for up to 12 weeks storage.

Food Uses of Palm Oil in Japan

Palm oil has many advantageous properties that make it well suited for manufacturing and processing food products in Japan. Its principal uses are in making margarine and shortening, and for deep frying instant noodles, tempura, and snack foods. Palm oil now enjoys a 22% share of all oils and fats used in preparing these foods. In addition, palm oil fractions such as palm olein, palm stearin, and palm midfraction are used increasingly in a variety of other food products, ranging from vegetable ghee and hard butter to chocolate and ice cream. According to official statistics, palm oil consumption in Japan has now increased to around 320,000 tons per year, and the indications are that its use in the food industry will continue to increase despite the fact that liquid oils remain the major oils in domestic cooking.

Thermal analysis of palm mid‐fraction, cocoa butter and milk fat blends by differential scanning calorimetry

AbstractCommercial samples of anhydrous milk fat (AMF), Ivory Coast cocoa butter (CB) and palm mid‐fraction (PMF) were blended in a ternary system. The melting characteristics of the blends were studied by differential scanning calorimetry (DSC). Results suggest that in the studies of interaction involving more than two fats, partial area (Ai) under the melting peak should be converted to partial enthalpy (ΔHi) rather than to solid fat index. The ΔH values of the blends decreased as the amount of AMF was increased and increased as the amount of CB was increased. In general, the effect of PMF was less pronounced compared to the effect of the other two fats. Eutectic effects within the ternary system could be detected by measuring the deviation of melting enthalpy by DSC, and from the corresponding values that were calculated for the thermodynamically ideal blends. The deviation reached a maximum when the amount of AMF was about 33%. On the binary line of CB/PMF, the eutectic effect was maximum at about 50–75% PMF. The interaction effect in the system was more noticeable at 30 and 20°C than at lower temperatures. Evaluation at 30°C was preferred because both the effect of AMF in the ternary system and the effect of PMF on the binary line were more readily observed.

Effect of oleo‐disaturated triacylglycerol content on properties of palm mid fraction, sal stearin and borneo tallow blends

Binary blends of palm mid fraction (PMF) with Borneo tallow (IP) and PMF with sal stearin (SLs) showed eutectic behavior. To produce a cocoa butter extender with steep melting profiles and containing not less than 70% solid fat at 20°C, the maximum amount of PMF1 (IV=49.2) and PMF2 (IV=39.8) that could be added to IP in PMF:IP binary systems were about 10% and 33%; whereas the amount of PMF2 that could be added to SLsl (IV=33.4), SLs2 (IV=31.7) and SLs3 (IV=30.3) in PMF2:SLs binary systems were about 7%, 10% and 38%, respectively. Blends of any PMF with an iodine value of 37 or lower with IP could fulfill the above specifications at any blend ratio.

Palm oil and palm kernel oil in food products

AbstractCocoa 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.