Physicochemical Properties and Sensory Attributes of Medium- and Long-Chain Triacylglycerols (MLCT)-Enriched Bakery Shortening

Six binary formulations of medium- and long-chain triacylglycerols (MLCT) fat and palm stearin and four ternary formulations of MLCT fat, palm stearin, and palm olein were produced. MLCT fat and palm stearin were mixed in ranges of 40–90% with 10% increments (w/w), while for the ternary formulations, 10% and 20% palm olein were substituted to palm stearin in MS 46 and MS 55 formulations. The solid fat content (SFC) by pulsed nuclear magnetic resonance and heating profiles using differential scanning calorimeter of these formulations were determined. Results obtained from SFC and heating profiles found that all the formulations melted completely at 55 °C. The high complete melting temperature is due to the stearic acid content in MLCT fat. Generally, increasing % MLCT fat (40–90%) in the formulations lowers the SFC curves at the measured temperatures (0–60 °C). The binary samples of MS 73, MS 82, and MS 91 showed SFC between 15% and 25% at room temperature (25 °C), which indicated that these formulations were suitable for shortening production. As the production cost of MLCT fat is high (approximately USD 3/kg), an attempt to reduce the proportion of MLCT fat in the shortening formulations was done by developing the ternary formulations. Shortenings formulated with 40:40:20 (MSO 442), 50:40:10 (MSO 541), and 50:30:20 (MSO 532) of MLCT fat/palm stearin/palm olein formulations had similar SFC% at 25 °C, and they were subsequently chosen to produce shortening. Using multivariate analysis, taste attribute showed positively and highly correlated to the melting temperature and SFC at 25 °C of the MLCT-enriched shortenings. In acceptance test, high correlation (R ² = 0.98) was only found on cakes made from MSO 442 and MSO 541 shortenings. Both untrained and trained panelists rated the Madeira cakes made from MSO 532 shortening the highest for overall acceptability.     

Characteristics of Microencapsulated Palm-Based Oil as Affected by Type of Wall Material

Microcapsules containing a blend of red palm olein (red POo) and refined, bleached and deodorised palm stearin (RBD POs) in the ratio of 60:40 were prepared with various wall materials using a spray-drying technique. The total oil content of the microcapsules ranged from 398 to 683·2gkg⁻¹. Surface oil and moisture content varied from 38·8 to 158·9gkg⁻¹ and 25 to 30gkg⁻¹, respectively. Carotene retention after spray-drying and after storage depended on the oil content and types of wall materials, and ranged from 194·65 to 215·28 and 158·8 to 203·1mgkg⁻¹, respectively. Microcapsules with the best characteristics were made from wall material containing proteinaceous material.     

Discrimination of palm olein oil and palm stearin oil mixtures using a mass spectrometry based electronic nose

To discriminate mixing ratios for mixtures of palm olein oil and palm stearin oil, an electronic nose based on mass spectrometer (MS-electronic nose) and GC were used. The intensities of each fragment from the palm olein oil and palm stearin oil by the MS-electronic nose were used for discriminant function analysis (DFA). When palm olein oil is mixed with palm stearin oil, more than 3% of stearin oil can be estimated by DFA. The obtained data were used for DFA. DFA plot indicated a significant separation of pure palm olein oil and palm stearin oil. The added concentration of palm stearin oil to palm olein oil was highly correlated with the first discriminant function score (DF1). When palm stearin oil was added to palm olein oil, it was possible to predict the following equation; DF1= −0.112×(conc. of palm stearin oil)+0.416 (r²=0.95). When palm stearin oil was added to palm olein oil, peak area of GC was correlated to DF1 by MS-electronic nose with ratio of palm olein oil vs palm stearin oil. The MS-electronic nose system could be used as an efficient method for the authentication of oil.     

Enzymatic interesterification of palm and coconut stearin blends

Hard fractions of palm oil and coconut oil, blended in the ratios of 90:10, 85:15, 80:20 and 75:25, were interesterified for 8 h using Lipozyme TL IM. Major fatty acids in the blends were palmitic acid (41.7–48.4%) and oleic acid (26.2–30.8%). Medium‐chain fatty acids accounted for 4.5–13.1% of the blends. After interesterification (IE), slip melting point was found to decrease from 44.8–46.8 °C to 28.5–34.0 °C owing to reduction in solids content at all temperatures. At 37.5 °C, the blends containing 25% coconut stearins had 17.4–19% solids, which reduced to 0.4–1.5% on IE, and the slip melting point (28.6 and 28.8 °C) indicated their suitability as margarine base. The reduction in solid fat index of the interesterified fats is attributed to the decrease in high‐melting triacylglycerols in palm oil (GS₃ and GS₂U type) and increase in triolein (GU₃) content from 1 to 9.2%. Retention of tocopherols and β‐carotene during IE was 76 and 60.1%, respectively, in 75:25 palm stearin and coconut stearin blend.     

Crystallisation kinetics of palm stearin,palm kernel olein and their blends

The kinetics of isothermal crystallisation of palm stearin, palm kernel olein and their blends (20–80 g/100 g palm stearin with 20 g/100 g increment) were determined using differential scanning calorimetry (DSC). The mechanism of crystallisation (n) was calculated by applying the Avrami equation using the crystallisation curves obtained at 10, 15 and 20 °C. The DSC isothermal crystallisation data at 10, 15 and 20 °C fitted well into the Avrami equation over the entire fractional crystallisation with correlation coefficient always greater than 0.98. Based on the Avrami exponent obtained, the palm stearin and palm kernel olein have different nucleation and growth mechanisms. The suggested mechanism for palm kernel olein was high nucleation rate at the beginning of crystallisation, which decreased with time, and plate-like growth (n = 2). On the other hand, the mechanism for palm stearin was instantaneous heterogeneous nucleation followed by spherulitic growth (n = 3). For blends of palm stearin and palm kernel olein, the mechanisms of crystallisation were 2 and 3 depending on the composition of the blends and crystallisation temperatures.     

大豆油调和不同熔点棕榈液油的冷藏试验

为了制备适应不同储存温度的豆油-棕榈液油调和油,以大豆油与不同熔点棕榈液油为原料,采用冷藏试验方法优化抑晶剂种类、用量和调和油配方。结果表明,羟基硬脂精是效果最佳的抑晶剂,其最佳添加量为0.025%;调和油1(豆油70%+10℃棕榈油30% +羟基硬脂精0.025%)在0℃环境下储存可保持16h以上澄清透亮,在5℃条件可保持72h以上澄清透亮;调和油2(豆油70%+18℃棕榈油30%+羟基硬脂精0.025%)在10℃环境下可保持30h以上澄清透亮;调和油3(豆油60%+18℃棕榈油40%+羟基硬脂精0.025%)在15℃环境下可保持20h以上澄清透亮;调和油4(豆油60%+24℃棕榈油40%+羟基硬脂精0.025%)在20℃环境下可保持10h以上澄清透亮。     

四种棕榈油结晶速度的研究

报道了棕榈油、棕榈软脂、棕榈硬脂及氢化棕榈油在0℃,10℃,20℃条件下的结晶速度,指出它们在结晶速度方面的差异,这些资料对人造奶油和起酥油生产具有实用意义。     

Determination of 3-monochloropropane-1,2-diol fatty acid esters in Brazilian vegetable oils and fats by an in-house validated method

An in-house validated GC-MS method preceded by acid-catalysed methanolysis was applied to 97 samples of vegetable oils and fats marketed in Brazil. The levels of the compounds ranged from not detected (limit of detection = 0.05 mg kg^?1) to 5.09 mg kg^?1, and the highest concentrations were observed in samples containing olive pomace oil and in products used for industrial applications, such as palm oil and its fractions (olein and stearin). The content of diesters and monoesters was also investigated by employing solid-phase extraction on silica cartridges, indicating that the majority of the compounds were present as diesters. This study provides the first occurrence data on these contaminants in Brazil and the results are comparable with those reported in other countries.     

A study on monitoring of frying performance and oxidative stability of cottonseed and palm oil blends in comparison with original oils

Blending polyunsaturated oils with highly saturated or monounsaturated oils has been studied extensively; however, in literature there is negligible information available on the blending of refined cottonseed oil with palm olein oil. Blending could enhance the stability and quality of cottonseed oil during the frying process. In the present study, the effects of frying conditions on physicochemical properties of the palm olein-cottonseed oil blends (1:0, 3:2, 1:1, 2:3, and 0:1, w/w) were determined and compared to the pure oils. The frying process of frozen French fries was performed in duplicate at 170 ± 5°C for 10 h without interruption. The oil degradations were characterized during deep-frying applications; peroxide, free fatty acid, and iodine value by standardized methods, fatty acid profile by using a gas chromatography-flame ionization detector, polar and polymeric compounds by using the high-performance size exclusion chromatography/evaporative light scattering detector technique. The present study clearly indicated that the oxidative and frying performances of pure palm olein oil and cottonseed oil significantly improved by blending application. Results clearly indicated that the frying performance of cottonseed oil significantly improved by the blending with palm olein oil. Except that free fatty acid content, all the physicochemical variables were significantly influenced by type of pure and blend oils. By increasing the proportion of palm olein oil in cottonseed oil, the levels of polyunsaturated fatty acids decreased, while saturated fatty acid content increased. The progression of oxidation was basically followed by detecting polar and polymeric compounds. The fastest increments for polar and polymeric compounds were found as 6.30% level in pure cottonseed oil and as 7.07% level in 40% cottonseed oil:60% palm olein oil blend. The least increments were detected as 5.40% level in 40% cottonseed oil:60% palm olein oil blend and 2.27% level in 50% cottonseed oil:50% palm olein oil blend. These levels were considerably below the acceptable levels recommended by the official codex. Therefore, the present study suggested that blending of cottonseed oil with palm olein oil provided the oil blends (50% cottonseed oil:50% palm olein oil and 40% cottonseed oil:60% palm olein oil, w/w) with more desirable properties for human nutrition.     

Optimisation of cake fat quantity and composition using response surface methodology

The influence of fat quantity and composition on the characteristics of a chemically leavened baked product was investigated, applying a central composite design combined with response surface methodology. Fats were blends of palm oil and palm olein with different slip melting points (from 36.3 to 11.3 °C, in dependence of increasing olein content). Fat content (from 5.3% to 30.7% on batter) and percentage of olein in the fat blend (from 42.7% to 92.2%) were varied. The increase of fat quantity enhanced cake softness, while lowering the volume; higher olein contents also decreased cake firmness. An optimised formulation containing 19.7% fat with 92% olein in the fat blend and showing good structural properties, comparable to those of a 18% butter reference cake, was identified. The optimised and the butter cake showed specific volume of 2.25 and 2.23 cm³ g^?1, respectively, and load at 25% strain of 7.68 and 5.63 N. These results demonstrated the possibility to replace butter with a liquid vegetable fat blend, thus increasing unsaturated fat content and reducing total cholesterol in the product.     

Directed interesterification of a brazilian palm oil and analysis of the original and interesterified oil and its fractions

A commercial sample of the Brazilian palm oil from the north eastern State of Bahia after neutralisation, washing and drying was interesterified in the presence of sodium-potassium alloy (NaK) at 30°C in a nitrogen atmosphere. The catalyst was destroyed by addition of water in a carbon dioxide atmosphere and the interesterified oil was crystallised from light petroleum, yielding an olein and stearin fraction. The fatty acid and triacylglycerol composition of the neutralised oil was determined by gas chromatography (g.c.) and high-performance liquid chromatography (h.p.l.c.) respectively and was shown to be similar to that of Malaysian and African palm oil. The compositions of the interesterified Brazilian oil and its liquid and solid fractions were also determined. The physicochemical characteristics of the olein obtained by interesterification with NaK, such as iodine value (96.8) and its softening point (below ?8°C) indicated its suitability for the use as salad oil.     

Zero trans shortening using rice bran oil, palm oil and palm stearin through interesterification at pilot scale

Fat blends, formulated by mixing refined, bleached and deodorised (RBD) palm oil (PO) or RBD palm stearin (PS) with RBD rice bran oil (RBO) in various ratios were subjected to chemical interesterification (CIE) at pilot scale using sodium methoxide (NaOMe) as catalyst. The resultant interesterified fat was processed through a margarine crystalliser under optimised conditions. The blends before and after CIE were investigated for triacylglycerol (TAG) composition, solid fat content (SFC) and melting characteristics, polymorphic form, fatty acid composition (FAC), bioactive (tocols, sterols, oryzanol) constituents and trans fatty acids (TFA). CIE was found to be very effective in terms of rearrangement of fatty acids (FAs) among TAGs and consequent changes in the physical characteristics. The SFC of the interesterified PS/RBO blends decreased significantly ( P  ≤ 0.05) when compared with those of PO/RBO blends. The interesterified binary blends with 50–60% PS and 40–50% RBO, and 70–80% PO and 20–30% RBO had SFC curves in the range of all-purpose type shortenings. CIE facilitated the formation of β' polymorphic forms. FAC of shortenings prepared using the optimised blends contained 15–20% C_18:2 polyunsaturated fatty acid (PUFA) and no TFA. Total tocol, sterol and oryzanol content of zero trans shortenings were 650–1145, 408–17 583 and 1309–14 430 ppm. CIE using NaOMe did not affect the bioactive constituents significantly ( P  ≤ 0.05).     

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。     

Optimisation of tripalmitin‐rich fractionation from palm stearin by response surface methodology

BACKGROUND: Solvent fractionation is effective in improving separation at low temperature, resulting in higher yield and purity of the final product. Tripalmitin (PPP) is an important substrate for the synthesis of human milk fat substitute (HMFS). In this study a fraction rich in PPP was separated from palm stearin by solvent fractionation. RESULTS: The PPP‐rich fraction was concentrated from palm stearin by acetone fractionation. Response surface methodology (RSM) was employed to optimise PPP purity (Y₁, %) and PPP content (Y₂, g kg^?1 palm stearin) with the independent variables fractionation temperature (X₁, 25, 30 and 35 °C) and weight ratio of palm stearin to acetone (X₂, 1:3, 1:6 and 1:9). The predictive models for PPP purity and PPP content of the solid fraction were adequate and reproducible, with no significant lack of fit and satisfactory levels of R². PPP purity showed a positive correlation with temperature and acetone ratio, whereas PPP content exhibited a negative correlation. The optimised fractionation condition for a targeted PPP‐rich fraction with > 92% PPP purity and > 225 g kg^?1 PPP content from palm stearin was predicted. CONCLUSION: The RSM model for optimising PPP purity and PPP content in the PPP‐rich fraction from palm stearin by acetone fractionation was valid. The scaled‐up PPP‐rich fraction obtained can be used as a substrate for the synthesis of 1,3‐dioleoyl‐2‐palmitoylglycerol, which is a main component of HMFS in infant formulas. Copyright © 2010 Society of Chemical Industry     

Production of trans‐free margarine stock by enzymatic interesterification of rice bran oil,palm stearin and coconut oil

BACKGROUND: Trans‐free interesterified fat was produced for possible usage as a spreadable margarine stock. Rice bran oil, palm stearin and coconut oil were used as substrates for lipase‐catalyzed reaction. RESULTS: After interesterification, 137–150 g kg^?1 medium‐chain fatty acid was incorporated into the triacylglycerol (TAG) of the interesterified fats. Solid fat contents at 25 °C were 15.5–34.2%, and slip melting point ranged from 27.5 to 34.3 °C. POP and PPP (β‐tending TAG) in palm stearin decreased after interesterification. X‐ray diffraction analysis demonstrated that the interesterified fats contained mostly β′ polymorphic forms, which is a desirable property for margarines. CONCLUSIONS: The interesterified fats showed desirable physical properties and suitable crystal form (β′ polymorph) for possible use as a spreadable margarine stock. Therefore, our result suggested that the interesterified fat without trans fatty acid could be used as an alternative to partially hydrogenated fat. Copyright © 2010 Society of Chemical Industry     

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。     

Occurrence of 3-MCPD and glycidyl esters in edible oils in the United States

Fatty acid esters of 3-monochloropropanediol (3-MCPD) and glycidol are processing contaminants found in a wide range of edible oils. While both 3 MCPD and glycidol have toxicological properties that at present has concerns for food safety, the published occurrence data are limited. Occurrence information is presented for the concentrations of 3-MCPD and glycidyl esters in 116 retail and/or industrial edible oils and fats using LC-MS/MS analysis of intact esters. The concentrations for bound 3-MCPD ranged from below the limit of quantitation (<LOQ) to 0.09 mg kg^?1 (ppm) in 22 unrefined oils and from 0.005 to 7.2 mg kg^?1 (ppm) in 94 refined oils. The concentrations for bound glycidol ranged from <LOQ to 0.03 mg kg^?1 (ppm) in unrefined oil samples and from <LOQ to 10.5 mg kg^?1 (ppm) in processed oil samples. The highest concentrations for both 3-MCPD and glycidol were seen in refined palm oil and palm olein samples. Palm olein samples also contained a higher percentage of 3-MCPD in mono-ester form than any other type of oil.     

A high performance liquid chromatography method for determination of furfural in crude palm oil

A modified steam distillation method was developed to extract furfural from crude palm oil (CPO). The collected distillates were analysed using high performance liquid chromatography (HPLC) coupled with an ultraviolet diode detector at 284 nm. The HPLC method allowed identification and quantification of furfural in CPO. The unique thermal extraction of CPO whereby the fresh fruit bunches (FFB) are first subjected to steam treatment, distinguishes itself from other solvent-extracted or cold-pressed vegetable oils. The presence of furfural was also determined in the fresh palm oil from FFB (without undergoing the normal extraction process), palm olein, palm stearin, olive oil, coconut oil, sunflower oil, soya oil and corn oil. The chromatograms of the extracts were compared to that of standard furfural. Furfural was only detected in CPO. The CPO consignments obtained from four mills were shown to contain 7.54 to 20.60 mg/kg furfural.     

隔膜压滤机在棕榈油干法分提中的应用

隔膜压滤机用于棕榈油分提过程的固液分离,在过滤完成后,通过压缩介质(水或空气等)依靠隔膜对滤饼压榨、挤干.采用隔膜压滤机,棕榈硬脂硬度提高、棕榈液油得率增加,分离效果好.过滤过程应用自动化控制,操作方便、产品质量稳定.     

Production of lipase‐catalyzed solid fat from mustard oil and palm stearin with linoleic acid by response surface methodology

BACKGROUND: Solid fat was produced from mustard oil and palm stearin through lipase‐catalyzed reaction, in which linoleic acid was intentionally incorporated. For optimizing the reaction condition of melting point and ω6/ω3 fatty acids, response surface methodology (RSM) was employed with three reaction variables such as substrate mole ratio of mustard oil (MO) to palm stearin (PS) (X₁), reaction temperature (X₂) and reaction time (X₃). RESULTS: The predictive model for melting point of solid fat was adequate and reproducible due to no significant lack of fit (P = 0.0764), P‐value (0.0037) of the model, and satisfactory level of coefficient of determination (R² = 0.92). For the ω6/ω3 ratio model, R² and P‐value were 0.89 and 0.0132, respectively, but lack of fit was significant (P = 0.0389). The melting point of the produced solid fat was affected by substrate mole ratio, whereas reaction temperature and time had no significant effect. The ω6/ω3 ratio of solid fat was influenced by substrate mole ratio and reaction temperature but not by reaction time. Based on ridge analysis, lower ω6/ω3 ratio was predicted by decreasing substrate mole ratio and reaction time, and by increasing reaction temperature. CONCLUSIONS: For producing solid fat with a specific melting point of 34.57 °C, a combination of 1:2 (X₁), 65.17 °C (X₂) and 21.46 h (X₃) was optimized, and the optimization was confirmed under the same reaction conditions. The solid fat contained palmitic (37.8%), linoleic (24.8%), oleic (21.3%), and erucic acid (9.7%), and its solid fat content was 30.3% and 10.3% at 20 and 30 °C, respectively. Copyright © 2009 Society of Chemical Industry