Ability of crystal promoters to delay fat bloom development in heat‐resistant compound chocolate with or without the presence of crystal inhibitor

Three additives that acted as crystal promoters (CP1, CP2 and CP3), at varying concentrations, were studied to determine their effect on fat bloom inhibition in heat‐resistant compound chocolates. CP1 was composed of mono‐ and diglycerides and polyglycerol esters from high‐oleic sunflower oil. CP2 consisted of mono‐ and diglycerides, lecithin and citric acid esters from blended canola oil and palm stearin. CP3 was composed of triglycerides from fully hydrogenated canola oil. Based on instrumental and sensory evaluations, all crystal promoters significantly (P ≤ 0.05) delayed fat bloom formation. Although compound chocolate with 0.25% CP1 showed more rapid bloom development than those with CP2 and CP3, addition of the crystal inhibitor sorbitan tristearate (STS) to the sample at 0.5% concentration further delayed (P ≤ 0.05) fat bloom development. The considerable delay in fat bloom formation suggests that the addition of carefully selected crystal modifier additives can improve the quality of heat‐resistant compound chocolates.     

The effect of process time and temperature on the accumulation of polar compounds in cottonseed oil during deep‐fat frying

The deterioration of oil during successive fryings of potato chips, especially the accumulation of polar compounds, was studied in the temperature range 155–195 °C. The content of polar compounds increased linearly with process time. The analysis of individual polar compounds showed that the products of thermal and oxidative degradation dominated over the products of hydrolytic cleavage as frying proceeded. Dimeric triglycerides increased linearly with process time, while polymerised triglycerides increased exponentially. The rate constants of the degradation reactions increased slightly with temperature, following an Arrhenius‐type equation. Oxidised triglycerides increased with frying time up to 6 h, thereafter remaining constant or increasing further upon prolonged frying. The increase was greater at higher temperature. The products of hydrolytic cleavage were not significantly affected by temperature. Mono‐ and diglycerides increased initially to reach a plateau, while free fatty acids remained almost constant throughout frying. The thermo‐oxidative alterations induced by heating the oil were also measured and compared with those observed during frying at the same temperature. Dimeric and polymerised triglycerides showed higher rates of increase during heating as compared with frying at the same temperature. © 2003 Society of Chemical Industry     

棕榈液油在调和油中应用研究

将熔点18℃棕榈液油分别与大豆油、菜籽油、玉米油和葵花籽油进行调配,得出不同季节条件下最佳调配比例;结果表明,棕榈液油作为一种调和油原料油,在春、夏、秋季均能应用于食用调和油。     

利用酯交换法改进棕榈油硬脂的加工性能

将棕榈油硬脂(ST)与大豆油(SBO)按不同比例混合再进行酯交换反应可以得到不同固脂特征的油脂。实验发现,其中的酯交换油脂IE(70%ST 30%SBO)最适合于加工成通用型起酥油。对这种酯交换油脂的打发性、软硬度及氧化稳定性进行了分析,并与目前市场上常见的全棕榈油基起酥油进行了比较,发现酯交换油脂的柔软度和打发性能均优于后者,但其氧化稳定性不及全棕榈油基起酥油。     

Trace elements and radionuclides in palm oil,soil, water,and leaves from oil palm plantations: A review

Oil palm (Elaeisguineensis) is one of the most productive oil producing plant in the world. Crude palm oil is composed of triglycerides supplying the world's need of edible oils and fats. Palm oil also provides essential elements and antioxidants that are potential mediators of cellular functions. Experimental studies have demonstrated the toxicity of the accumulation of significant amounts of nonessential trace elements and radionuclides in palm oil that affects the health of consumers. It has been reported that uptake of trace elements and radionuclides from the oil palm tree may be from water and soil on the palm plantations. In the present review, an attempt was made to revise and access knowledge on the presence of some selected trace elements and radionuclides in palm oil, soil, water, and leaves from oil palm plantations based on the available facts and data. Existing reports show that the presence of nonessential trace elements and radionuclides in palm oil may be from natural or anthropogenic sources in the environment. However, the available literature is limited and further research need to be channeled to the investigation of trace elements and radionuclides in soil, water, leaves, and palm oil from oil palm plantations around the globe.     

Influence of fried and fried‐treated oils with different filter aids on rat health

Soybean, sunflower, palm and cottonseed oils were fried continuously at 180 ± 5 °C for 12 h. Fried oil quality was regenerated by adding individually Magnesol XL, diatomaceous earth and kaolin at 2% level, then stirring mechanically at 105 °C for 15 min and filtering. A set of nutritional experiments was conducted in which rats were administered standard diets containing non‐fried, fried and fried‐treated oils with various filter aids. The safety limits of the fried‐treated oils were recognized by measuring the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (AP), and levels of total lipids, total cholesterol, HDL cholesterol and LDL cholesterol of rat sera. Also, histopathological evaluation of rat liver tissues was microscopically done to detect any damage that might occur due to feeding rats on non‐fried, fried and fried‐treated oils. Administration of fried oils to rats induced significant rises in activities of ALT, AST and AP, and increases in the levels of total lipids and total cholesterol. The results demonstrate that there were non‐significant changes in sera levels of LDL and HDL cholesterol in rats fed diets containing various types of soybean, sunflower and cottonseed oils. Administration of fried‐treated oils to rat diets indicates that the activities of ALT, AST and AP and levels of sera constituents were similar to those of rats given non‐fried oils. Palm oil exceptionally behaved differently from the other oils. Palm oil raised sera total cholesterol and LDL cholesterol and lowered HDL cholesterol level. Histopathological examination of rat liver tissues indicated that changes paralleled the biochemical data. Copyright © 2006 Society of Chemical Industry     

Palm oil: a healthful and cost-effective dietary component

Palm oil is an excellent choice for food manufacturers because of its nutritional benefits and versatility. The oil is highly structured to contain predominantly oleic acid at the sn2-position in the major triacylglycerols to account for the beneficial effects described in numerous nutritional studies. Oil quality and nutritional benefits have been assured for the variety of foods that can be manufactured from the oil directly or from blends with other oils while remaining trans-free. The oxidative stability coupled with the cost-effectiveness is unparalleled among cholesterol-free oils, and these values can be extended to blends of polyunsaturated oils to provide long shelf-life. Presently the supply of genetic-modification-free palm oil is assured at economic prices, since the oil palm is a perennial crop with unparalleled productivity. Numerous studies have confirmed the nutritional value of palm oil as a result of the high monounsaturation at the crucial 2-position of the oil's triacylglycerols, making the oil as healthful as olive oil. It is now recognized that the contribution of dietary fats to blood lipids and cholesterol modulation is a consequence of the digestion, absorption, and metabolism of the fats. Lipolytic hydrolysis of palm oil glycerides containing predominantly oleic acid at the 2 position and palmitic and stearic acids at the 1 and 3 positions allows for the ready absorption of the 2-monoacrylglycerols while the saturated free fatty acids remain poorly absorbed. Dietary palm oil in balanced diets generally reduced blood cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides while raising the high-density lipoprotein (HDL) cholesterol. Improved lipoprotein(a) and apo-A1 levels were also demonstrated from palm oil diets; an important benefits also comes from the lowering of blood triglycerides (or reduced fat storage) as compared with those from polyunsaturated fat diets. Virgin palm oil also provides carotenes apart from tocotrienols and tocopherols that have been shown to be powerful antioxidants and potential mediators of cellular functions. These compounds can be antithrombotic, cause an increase of the prostacyclin/thromboxane ratio, reduce restenosis, and inhibit HMG-CoA-reductase (thus reducing) cholesterol biosynthesis). Red palm oil is a rich source of beta-carotene as well as of alpha-tocopherol and tocotrienols.     

Influence of chemical refining process and oil type on bound 3-chloro-1,2-propanediol contents in palm oil and rapeseed oil

The formation of bound 3-chloro-1,2-propanediol (3-MCPD-ester) in oils during chemical refining process was investigated for two palm oils and one rapeseed oil. Additionally, contents of mono- and diglycerides as well as total chlorine and chloride were determined. For all oils the deodorisation step representing one part of the refining process had the main impact on formation of 3-MCPD-esters whereas a direct effect of the other process steps could be neglected. 3-MCPD values in the range of 4–5 ppm for palm oil and 1 ppm for rapeseed oil were found. The chloride content was below detection limit. However, measurable amounts of total chlorine were found in palm oil with the highest 3-MCPD-ester contents. A considerable part of this total chlorine in the refined palm oil was embedded in the 3-MCPD-esters. On the other hand, content of diglycerides as the other potential pre-cursor was between 1% and 10% exceeding the 3-MCPD-ester contents by up to five magnitudes.     

Evaluation of shortenings based on various palm oil products

Several formulations based on blends of hydrogenated palm oil (MP 41·5°C) and palm stearin (IV 44) with other liquid oils, on direct blends of palm stearin with other liquid oils, and on 100% inter-esterified palm olein, were used as feedstocks in shortening production. The shortenings were stored at 20°C over a period of one month. Physicochemical characteristics, creaming properties and baking performance of the shortenings were evaluated and compared with the best shortening on the market. Slip melting point of the shortenings ranged from 41·5 to 46·4°C. Palm-cottonseed oil shortenings had higher solid fat contents at all temperatures than palm-soya bean or palm-low erucic acid rapeseed oil shortenings. The shortenings were rich in C₅₀, C₅₂and C₅₄ glycerides. Creaming power after 12 min of beating ranged from 1·55 to 1·77 cm³ g^?1. Palm stearin-cottonseed (3:2) oil shortening showed the best creaming performance. The specific volume of cakes ranged, for the experimental shortening, from 90% to 101% from the control, with low erucic acid-palm blends showing the best performance. In applications for both aerated cream and cakes, inter-esterified palm olein was excellent.     

The physical properties of modified palm oil

Palm oil has been treated by partial lipase hydrolysis and by interesterification with excess glycerol and the effects on the chemical and physical properties have been investigated. Lipase hydrolysis preferentially removes unsaturated acids and the neutral glycerides remaining after removal of the free fatty acids therefore have an increased solids content at 20°C. Both differential scanning calorimetry (d.s.c.) and X-ray examination show that the crystalline phases present above 20°C are more heterogeneous after lipase treatment. Interesterification results in a mixture of tri- and diglycerides with an increased solids content at 20°C and a marked tendency to form β phase crystals. Some potential practical applications are discussed.     

马来西亚棕榈油在食品和饲料中的应用及油棕行业可持续发展的研究进展

目前棕榈油是全球第一大产量的植物油,其性状稳定,含有丰富的维生素 E和类胡萝卜素等营养成分,且价格具有竞争力,因此被广泛应用于食品加工及饲料等行业。马来西亚作为世界棕榈油主要生产国和出口国之一,对全球棕榈油市场具有重要贡献。综述了马来西亚棕榈油生产、贸易及可持续发展状况,并对棕榈油在食品和饲料行业的应用进行总结,以期为棕榈油的消费和应用提供参考。     

Functionality of Palm Oil as a Stabilizer in Peanut Butter

ABSTRACT: Studies have shown that palm oil is an effective stabilizer in peanut butter. The objective of our investigation was to better define the role of palm oil as a stabilizer. Peanut butters without and with palm oil added at concentrations of 1.5, 2.0, and 2.5% (w/w of peanuts), and Fix-X™ (hydrogenated rapeseed and cottonseed oils as commercial control) were stored at 0, 21, 30, and 45 °C for 23 wk. Palm oil improved the oil holding capacity (OHC) of peanut butters, but had no effect on their adhesiveness and hardness characteristics. The unstabilized and palm oil-stabilized peanut butters were not as good as the Fix-X™ stabilized peanut butters with regard to their OHC, hardness, and adhesiveness characteristics.     

EFFECT OF PRESERVATION WITH SACCOGLOTTIS GABONENSIS ON THE BIOCHEMISTRY AND SENSORY ATTRIBUTES OF FERMENTING PALM WINE

Fresh palm‐wine, from Raphia hookeri was treated with different amounts of Saccoglottis gabonensis. The alcohol content, refractive index, assimilation of sugars and assimilation of nitrates were mcnitored (for 4 days) in treated samples and untreated controls (containing no S. gabonensisj. Fermentation rates were monitored by determining CO₂ production as well as pH and tit ratable acidity changes within the same period. Sensory attributes of fresh and treated palm wine were compared. Sensory evaluation studies were carried out on (1) The fresh palm wine, (2) Palm‐wine stored for 4 days at ambient temperature (27C‐29C) and (3) Palm‐wine stored for 30 days at ambient temperature. Treatment with S. gabonensis led to increased alcohol content and CO₂ production with lower sugar content (sucrose, glucose and maltose) and pH, than in control samples. There were no significant variations in the refractive indices of treated and untreated samples. CO₂ production decreased with each successive fermentation day in both treated and untreated samples. Panelists preferred the sensory properties of fresh palm‐wine to that of palm‐wine treated with S. gabonensis. However, by the second day the sensory characteristics of treated palm‐wine was preferred. Until the 4th day, the color and taste of treated palm‐wine ‐was acceptable while the untreated samples became unacceptable. By the 30th day both treated and untreated palm‐wine samples became unacceptable.     

Changes in the lipid and fatty acid composition during maturation of seeds of white mustard (Sinapis alba)

The oil content of the seeds of white mustard (Sinapis alba) was determined 3 weeks after flowering and at weekly intervals until seeds were matured. Examination of the lipid classes by quantitative t.l.c. showed that triglycerides were the major components at all stages and were accompanied by sterol esters, diglycerides and polar lipids; monoglycerides were only detected in the first 2 samples. The fatty acid composition of the total oil and the mono-, di- and triglycerides and sterol esters was determined by g.l.c. The 7 major fatty acids, namely palmitic, stearic, oleic, linoleic, linolenic, eicosenoic and erucic acids were present at all stages of maturity. The fatty acid composition of the triglyceride fraction was similar to that of the total oil whereas the mono- and diglycerides and sterol esters contained a relatively higher proportion of saturated fatty acids. Erucic acid, the major acid of the oil from mature seeds did not become the major acid until 35 days after flowering. The results are discussed in relation to pathways of lipid synthesis in higher plants.     

In Situ Bioconversion of Coconut Oil via Coconut Solid State Fermentation by Geotrichum candidum ATCC 34614

Coconut base solid state fermentation was carried out by Geotrichum candidum ATCC 34614 for in situ coconut oil bioconversion. Coconut oil, which contains highly saturated medium chain triglycerides, was partially bioconverted into a combination of medium chain diglycerides, medium chain monoglycerides and medium chain fatty acids by this fungus lipolytic activity. The product demonstrated improved aroma, flavor, thermal behavior and antibacterial activity. Maximum triglycerides conversion (76.5 %) occurred at 40 % moisture content and 50 % oil content after 25 days of incubation. Bioconverted coconut oil revealed as much as 95 % antibacterial activity as well as altered thermal characteristic towards lower melting and higher crystallization points. The fermented culture also revealed highly fruity and flora notes which contained five main short- and medium-chain esters known as aromatic compounds. The present study established the possibility of using G. candidum ATCC 34614 in coconut solid culture for bioconversion of coconut oil, which improves the fermented product characteristics.     

PRODUCTION OF PALM OIL REFERENCE MATERIALS FOR THE DETERMINATION OF SOLID FAT CONTENT

ABSTRACT

Three palm oil reference materials were produced for solid fat content analysis employing the Malaysian Palm Oil Board (MPOB) Test Methods. Thirteen laboratories participated in the characterization study, where the solid fat content in palm oil, palm olein and palm stearin were identified at temperature range from 0 to 45C. The consensus values were calculated based on the acceptability of statistical results from collaborating laboratories. Both of the consensus values and their uncertainties (%) for each reference material are as follows: 71.12 ± 1.82% (0C), 54.07 ± 1.05% (10C), 37.44 ± 0.88% (15C), 24.18 ± 1.09% (20C), 13.32 ± 0.86% (25C), 7.64 ± 0.28% (30C), 4.05 ± 0.14% (35C) and 1.25 ± 0.49% (40C) for SFC of palm oil, 66.32 ± 1.93% (0C), 43.53 ± 1.32% (10C), 22.50 ± 0.78% (15C), 6.68 ± 1.14% (20C) and 1.40 ± 0.35% (25C) for SFC of palm olein, and 78.09 ± 1.23% (0C), 67.66 ± 0.71% (10C), 56.29 ± 1.18% (15C), 44.37 ± 1.13% (20C), 30.22 ± 1.25% (25C), 20.08 ± 0.58% (30C), 13.72 ± 0.32% (35C), 8.97 ± 0.72% (40C) and 5.06 ± 0.41% (45C) for solid fat content of palm stearin.

PRACTICAL APPLICATIONS

The implementation of the ISO 17025 accreditation should be encouraged for testing laboratories to assure the traceability of analysis performed. This accreditation requires the use of certified reference materials to ensure that the analysis performed is parallel to the ISO 17025 standards. However, the unavailability of palm oil reference materials will affect the implementation of such standards for laboratories that are performing palm oil analyses. Hence, this study is aimed to characterize and certify the palm oil reference materials for determination of solid fat content. The establishment of this study is hoped to increase the credibility of laboratories, which are involved in the palm oil analysis. This will also promote the Malaysia Palm Oil Board as a center for the certification of palm oil reference materials.     

Effect of Lipid Physical State of Palm Derivatives on β‐Carotene Bleaching

This research was addressed to study the effect of lipid physical state on bleaching kinetics of β‐carotene. To this aim, β‐carotene was added to palm oil and palm stearin and the samples were stored at increasing temperatures allowing different degree of crystallization. Phase transition properties of palm derivatives were studied by differential scanning calorimetry and synchrotron X‐ray diffraction, whereas β‐carotene bleaching kinetics were followed by measuring color changes. Bleaching proceeded at comparable rate in palm oil and palm stearin containing systems stored at 20 and ?18 °C, whereas the color changes showed a maximum rate at 4 °C in palm stearin samples and at ?7 °C in palm oil systems. Arrhenius plot clearly highlighted deviations from the linearity underlining the crucial role of lipid physical properties in determining the bleaching rate. The location and the compartmentalization of β‐carotene in the fat lattice could affect its chemical stability.     

世界棕榈油的生产贸易及我国消费现状分析

棕榈油作为世界主要油脂品种之一,其生产量和贸易量均位居世界第一,在植物油生产和消费市场中占有极其重要的地位。详细论述了近年世界棕榈油的生产及进出口贸易情况;并对近年我国棕榈油的进口数量、品种、消费以及分提加工现状进行了分析。     

棕榈油基沙拉酱的制备工艺

利用棕榈液油部分替代传统沙拉酱中的大豆油制备棕榈油基沙拉酱。研究产品配方和加工工艺条件。通过单因素实验和正交实验确定,将30%棕榈液油和70%大豆油混合制备沙拉酱,最佳配方和乳化条件:选用复合乳化剂海藻酸丙二醇酯和黄原胶(等比例),乳化剂添加量0.22%,水的加入量10%,变性淀粉添加量0.8%,乳化时间10min。在此条件下制备的沙拉酱感官性质及功能性质良好,0℃条件下存放3个月乳化体系稳定,无油水分离现象发生。对棕榈油基沙拉酱进行质构分析,结果表明该产品乳化体系稳定,其质构特征与全部用大豆油制备的沙拉酱样品相近。