Comparison of the stability of palm olein and a palm olein/canola oil blend during deep‐fat frying of chicken nuggets and French fries

Stability of palm olein (PO) and a blend 50% palm olein/50% canola oil (POC) during deep‐fat frying at 180 °C of French fries (FF) or chicken nuggets (CN) was studied through the determination of physical and chemical parameters in the fresh and used oils. Degradation at the end of the study resulted in total polar compounds of 12–13.5% for PO and 11.5–14.5% for POC and viscosity of 65–123.3 cP for PO and 63–72.8 cP for POC. Lower peroxide values (5.33–6.32) were obtained for the blend (PO had 5.21–8.55). Food type affected colour parameters and p‐anisidine value of the oils. For CN, the lowest fat content and higher hardness were obtained when they were fried in PO. CN caused a faster deterioration in the oils, in comparison with FF, especially in POC. Gas chromatography allowed to observe differences in fatty acids composition for both used oils.     

亚麻籽油和棕榈液油煎炸油条过程中的品质变化

为了获得亚麻籽油的最适煎炸条件,在（180±5） ℃下,以GB 2716—2018中规定极性化合物含量达到27%为煎炸终点,对亚麻籽油和棕榈液油在油条连续煎炸过程中理化指标进行检测和比较,同时对油条进行感官评定。结果表明：在连续煎炸油条过程中,两种植物油的酸值、总氧化值、极性化合物及聚合物含量均随着煎炸时间的延长而不断增加,但在4 h以内,亚麻籽油极性化合物含量较低;亚麻籽油的极性化合物含量在煎炸13 h后达到27.78%,而棕榈液油的极性化合物含量在煎炸18 h后达到27.27%;相较于棕榈液油,在油条煎炸过程中,亚麻籽油中多不饱和脂肪酸含量不断减少,尤其是α-亚麻酸下降幅度更大;亚麻籽油140 ℃下的氧化诱导期均在1 h以内,远低于棕榈液油;油条感官评定表明棕榈液油更适宜于油条煎炸。研究表明亚麻籽油适合短时（<4 h）高温煎炸,不建议长时间深度煎炸。     

Comparative study of fatty acid composition,vitamin E and carotenoid contents of palm oils from four varieties of oil palm from Côte d'Ivoire

BACKGROUND: Fatty acid, tocopherol, tocotrienol and carotene contents were assessed in four oil palm species from the National Centre of Agronomical Research of Côte d'Ivoire, two of which were the basal Lamé (HP1) and Deli (HP2) collections and two of which resulted from crossings between HP1 and HP2 varieties of Eleais guineensis, HP3 and HP4 being identified as the first and second cycle selection, respectively. RESULTS: Palm oil species were characterized by the richness in polyunsaturated fatty acids composition (48–60%) compared to saturated fatty acids (40–52%), especially the first variety, which was from the base collection, and the two hybrids ensuing from crossing. Total carotene content of those varieties was higher and accounted for 832–3575 µg g^?1, and the β‐carotene level (580–2390 µg g^?1) was predominant. Total vitamin E content was 864–1124 µg g^?1, with a notable higher content of tocotrienols, especially γ‐and α‐tocotrienol, ranging from 400 to 515 µg g^?1 and from 238 to 350 µg g^?1, respectively. CONCLUSION: Crossing seemed to be useful in improving the performance and analytical characteristics of the base collection materials. Copyright © 2009 Society of Chemical Industry     

油炸对鸡肉中反式脂肪酸含量及棕榈油品质的影响

以棕榈油作油炸油,油炸表面涂抹蜂蜜水的鸡腿,研究棕榈油连续使用时间对鸡肉中反式脂肪酸含量的影响,并测定棕榈油的酸价和羰基值,探究其品质变化规律。结果表明:以棕榈油作油炸用油,油炸后鸡肉中所含的主要反式脂肪酸为C18∶1 9t;棕榈油使用2~10 h,鸡肉中总反式脂肪酸含量显著增加。棕榈油酸价在油炸过程中一直符合食用油煎炸过程中卫生标准;而羰基值在160℃下使用10 h时达到54.66 meq/kg,超过国标规定的最大限量,180℃下使用8 h即将超标,而200℃时已经超标。因此,以棕榈油进行油炸加工鸡肉时,应选择160℃左右的加工温度,并控制棕榈油使用时间不超过10 h。      

毛细管气相色谱法检测方便面中棕榈油主要脂肪酸含量

方便面经酸水解后用乙醚提取，其中脂肪酸用ＫＯＨ一甲醇快速甲脂化，用毛细管气相色谱法测定，并重点对某企业生产的方便面产生异味原因进行剖析     

Influence of composition on degradation during repeated deep‐fat frying of binary and ternary blends of palm,sunflower and soybean oils with health‐optimised saturated‐to‐unsaturated fatty acid ratios

The American Heart Association recommended the fatty acid balance contributed by all the fats in our diet, suggesting it would be best at approximately 1:1:1 for saturated (SFA), monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA), respectively. Three individual oils: palm oil (PO), soybean oil (SBO) and sunflower oil (SNF) and their binary and ternary blends were prepared and used for repeated deep‐fat frying of French fries. The acid value, peroxide value, p‐anisidine value and Totox values, as well as oxidative stability, contents of total polar compounds, tocochromanols, triacylglycerol dimers and oligomers, were determined in individual and blended oils. The lowest Totox value and highest stability were found for PO, and the opposite data were obtained for SNF and SBO. The degradation of tocochromanols in blends ranged from 91% to 95% after 4 days of frying, while in individual oils, it was 63% in SBO, 71% in SNF and 100% in PO. The lowest formation of dimers and oligomers was observed for the PO: SNF blend. Obtained results showed that only pure PO was a better frying medium than its blends with SBO and SNF. However, a prepared blend had a better fatty acid composition for human health and was more stable than pure SBO and SNF.     

The effect of palm oil or canola oil on feedlot performance,plasma and tissue fatty acid profile and meat quality in goats

Twenty-four entire male Kacang kid goats were fed diets containing 3% canola (n = 12) or palm oil (n = 12) supplements for 16 weeks. The goats had an initial live weight of 14.2 ± 1.46 kg and were fed a mixed ration ad libitum (10.4 MJ/ME and 14% crude protein). There was no difference in feedlot performance due to diet. Inclusion of canola oil reduced (P < 0.05) kidney fat weight and increased (P < 0.05) linolenic acid (18:3n − 3) concentration in the blood plasma, m. longissimus lumborum (LL), liver, and kidney. The palm oil diet increased (P < 0.05) myristic (14:0) and palmitic (16:0) acid content in the blood, but this did not alter these fatty acids in the LL muscle. Lipid oxidative substances in the liver and LL from palm oil fed kids were higher (P < 0.05) than those from canola supplemented kids. The incorporation of canola oil into the goats' diet increased muscle omega-3 fatty acid content, but lipid oxidation was lowered in the blood and muscle LL.     

油炸中棕榈油与鸡柳脂肪酸组成的变化及其相互影响

为研究油炸过程中棕榈油及鸡柳脂肪酸组成变化及相互影响规律,利用气相色谱法对棕榈油以及炸鸡柳中脂肪酸组成的变化进行分析,并用国标法测定油炸油的酸价和过氧化值,借助主成分分析法探讨油炸油脂肪酸组成对油脂氧化稳定性的影响。结果表明:油炸温度较低(≤200℃)时,棕榈油脂肪酸没有明显变化,在温度极高(>200℃)时,棕榈油中不饱和脂肪酸含量显著下降(p<0.01),反式脂肪酸的含量显著增加(p<0.01)。鸡柳在油炸过程中吸收油炸油,并且吸收油脂的量随着炸制时间的延长而增加。同时,鸡柳中浓度高的脂肪酸C20∶4、9c C16∶1、9c12c C18∶2、9c12c15c C18∶3也会释放到棕榈油中。主成分分析结果显示棕榈油中多不饱和脂肪酸C18∶2和C18∶3对于酸价和过氧化值的影响最大。      

Detection of fresh palm oil adulteration with recycled cooking oil using fatty acid composition and FTIR spectral analysis

There is a growing concern over the food safety issue related to increased incidence of cooking oil adulteration with recycled cooking oil (RCO). The objective of this study was to detect fresh palm olein (FPO) adulteration with RCO using fatty acid composition (FAC) and Fourier-transform infrared spectroscopy (FTIR) spectral analyses combined with chemometrics. RCO prepared in the laboratory was mixed with FPO in the proportion ranged from 1% to 50% (v/v) to obtain the adulterated oil samples (AO). FACs for FPO, RCO, and AO were determined using gas chromatography equipped with a flame ionization detector (GC-FID). The compositions of most fatty acids in RCO lied within the normal ranges of Codex standard, except for C8:0, C10:0, C11:0, C15:0, trans C18:1, and polyunsaturated fatty acids (PUFAs), C20:5. PUFAs showed a consistent decreasing trend with increasing magnitude of change with respect to increasing adulteration level and thus might be a good indicator for detecting FPO adulteration with RCO. The evaluation parameters (coefficient of determination, root mean standard error) of the FTIR-partial least square (PLS) model of palm oil adulteration with recycled oil are R² = 0.995 and 3.25, respectively. For FTIR spectral analysis, the distinct variations in spectral regions and aberrations in characteristic bands between FPO and RCO were observed. The optimized PLS calibration model developed from normal spectral of the combined region at 3602–3398, 3016–2642, and 1845–650 cm^?1 overpredict the adulteration level. On the other hand, the discriminant analysis classification model was able to classify the FPO and AO into two distinct groups. Improvement of the principles of combined techniques in authenticating AO from fresh oil is beneficial as a guideline to detect adulteration in cooking oil.     

Extraction and physicochemical properties of low free fatty acid crude palm oil

Response surface methodology was applied to optimize the pre-treatment of oil palm (Elaeis guineensis) fruit spikelets before oil extraction. The treatment applied was drying at different times and temperatures. The dried spikelets were then subjected to mechanical processes and crude oil was extracted. A central composite design was employed to study the responses, namely percentage of free fatty acids (FFA) and oil yield, and the optimum conditions for minimum FFA and maximum oil yield were identified from their respective contour plots. It was concluded that the pre-treatment should be carried out for 12.8 h at 66.8 °C. Under the optimum conditions, the corresponding response values for FFA and oil yield were 1% and 33.6%, respectively. Some of the physicochemical properties of the extracted oil were then determined. The low free fatty acid crude palm oil exhibited good physicochemical properties and could be useful for industrial applications.     

棕榈油与猪油在组成结构和功能特性上的比较

比较了3种棕榈油和6种猪油产品在理化指标、营养与功能特性指标以及脂肪酸组成及其在甘油三酯Sn-2位上的分布情况,以判断棕榈油对猪油的可替代性.结果表明,棕榈油和猪油的熔点、碘值、酸值、过氧化值等理化指标很接近;棕榈油不含胆固醇,具有比猪油较高的V_E含量和氧化稳定性;在可塑性方面,精炼棕榈油与猪板油相当,而且好于猪杂油和猪膘油,棕榈硬脂与猪骨油相当,棕榈液油与猪皮油相当;虽然棕榈油和猪油的脂肪酸组成具有相似性,猪油的不饱和脂肪酸含量略高于棕榈油的不饱和脂肪酸含量,但是棕榈油的Sn-2位上主要分布不饱和脂肪酸,而猪油的Sn-2位上主要分布饱和脂肪酸,使棕榈油比猪油更加容易消化吸收.     

热加工过程中棕榈油理化特性、脂肪酸与自由基的变化研究

以棕榈油（24℃）为原料,采用国标法测定棕榈油在不同温度（160、180、200℃）下常规理化指标（酸价、过氧化值、丙二醛值、p-茴香胺值和总氧化值）随时间的变化,在此基础之上,分别采用GC-MS法与电子自旋共振（ESR）法对180℃下棕榈油脂肪酸组成和自由基含量变化进行测定。结果表明,加热温度越高和加热时间越长棕榈油理化指标值越大,其中过氧化值呈现先上升后下降趋势。脂肪酸组成结果表明,棕榈油中饱和脂肪酸与不饱和脂肪酸比例约为1∶1,且随着加热时间延长,比例基本不变。ESR实验表明,加热时间越长,2-苯叔丁基硝酮（PBN）捕获的自由基量越多,棕榈油氧化程度越深。      

火麻油总脂肪酸及sn-2位脂肪酸组成分析

采用气相色谱法测定火麻油中总脂肪酸和sn-2位脂肪酸的组成和含量,并与其他9种常见植物油进行对比,旨在为火麻油的营养价值研究提供基础数据。结果表明,3种不同品牌火麻油主要由软脂酸（C16∶ 0）、硬脂酸（C18∶ 0）、油酸（C18∶ 1n9c）、亚油酸（C18∶ 2n6c）、α-亚麻酸（C18∶ 3n3）组成,其中多不饱和脂肪酸含量为70.57%~78.73%,sn-2位多不饱和脂肪酸含量为77.61%~83.74%,说明以亚油酸和α-亚麻酸为主的多不饱和脂肪酸更易连接在甘三酯结构的sn-2位上。另外,对比其他9种常见植物油,火麻油总脂肪酸和sn-2位脂肪酸中油酸含量均最低,亚油酸和亚麻酸含量较高;多不饱和脂肪酸含量均最高,分别为77.90%和83.74%;n-6系脂肪酸与n-3系脂肪酸比例分别为3.7∶ 1和4.2∶ 1。研究结果表明,火麻油是一种不饱和脂肪酸含量较高且易于被人体吸收代谢的植物油。     

Separation/fractionation of triglycerides in terms of fatty acid constituents in palm kernel oil using supercritical CO2

Separation of triglycerides in terms of fatty acid constituents in palm kernel oil (PKO) from dehulled ground palm kernel using supercritical carbon dioxide (SC‐CO₂) as a solvent at 40 and 80 °C and pressures of 20.7, 27.6, 34.5, 41.4 and 48.3 MPa was studied. The extraction was continuous and PKO was fractionated into four fractions. Triglycerides with differing fatty acid contents of caprylic (C8), capric (C10), lauric (C12), myristic (C14), palmitic (C16), stearic (C18:0), oleic (C18:1) and linoleic (C18:2) acid were separated in different percentages in different fractions. About 70% of PKO comprises triglycerides with C8–C12 fatty acids and these fatty acids were mostly extracted in fractions 1and 2. As a result, higher yields were observed in these fractions, especially at pressures higher than 27.6 MPa. The C16 and C18:2 components were extracted in fractions 3 and 4. These triglycerides form only a part of the remaining 30% of the fatty acid composition of PKO, hence the evidently diminishing yield in the later fractions. However, the compositions were found to be statistically significant for higher pressures and fraction times according to the type of fatty acid constituents. Copyright © 2006 Society of Chemical Industry     

Application of hydrogenated palm kernel oil and palm stearin in whipping cream

Non-dairy creams made from hydrogenated palm kernel oil (HPKO) are generally more stable than dairy creams. However, in summer the emulsion tends to separate. This paper outlines some steps that were taken to modify the HPKO with the intention of increasing the stability without affecting whipping performance. This was achieved by blending HPKO with palm stearin (POs). Interesterification was employed to eliminate the increase in solid fat content at 37°C and 40°C. Results of the experiment showed that an interesterified HPKO: POs 66:34 blend proved to have satisfactory whipping performance when compared to creams made with HPKO alone.     

不同熔点棕榈油脂肪酸组成和SFC测定分析

分析七种不同棕榈油脂肪酸组成及在0℃~25℃(5℃间隔)温度下固体脂肪含量(SFC)及其变化规律。结果表明:随熔点降低,棕榈酸含量有逐渐降低趋势,而油酸和亚油酸含量则逐渐上升;饱和脂肪酸含量逐渐减少,而不饱和脂肪酸含量则逐渐升高;低熔点棕榈油营养价值要比高熔点棕榈油高;在不同温度段,SFC值增加幅度有所不同。该试验为棕榈油进一步深加工研究提供参考数据。     

Determination of free fatty acids in palm oil samples using non-aqueous flow injection titrimetric method

Flow injection (FI) non-aqueous titrimetric methods for the determination of free fatty acids (FFA) in palm oil samples are described. Single-line and two-line FI manifolds using phenolphthalein (PHP) and bromothymol blue (BTB) as indicators were developed. The method is based on the monitoring of the changes of absorbance of the indicators used from basic–acidic–basic form (pink–colourless–pink for PHP, blue–yellow–blue for BTB) as a result of the neutralization of KOH that was used as carrier stream by the injected FFA sample. FI parameters such as carrier and reagent concentration, flow-rate, length of reaction coil, size of mixing chamber and injected volume were optimized. The single-line manifold with PHT as indicator is recommended for the determination of samples with acidity degree (a.d.) higher than 0.4, but the oil samples need to be diluted with 2-propanol before their injection. For lower acidities (a.d. < 0.4), a two-line manifold with BTB as indicator is recommended. The two-line manifold allows direct injection of oil samples (no off-line dilution required). The optimized FIA method is linear over the range 0.4–10.0 a.d. (based on palmitic acid) for single-line manifold and 0.11–0.50 a.d. for the two-line manifold. Sample throughput of 35–74 and 21–46 samples h⁻¹ for single-line and two-line manifolds, respectively, were achieved. Fifty different samples of palm oils were tested using the appropriate FIA manifolds, and results were compared with the standard PORIM procedure which involves manual titration. Good correlations between the two methods were obtained (r², at least 0.92) UV–VIS absorption spectra indicate that the absorption of these oil samples were minimum at the detection wavelengths (562 nm for PHP and 627 for BTB), indicating that the method is negligibly interfered from the background colour of the samples.     

Effect of varying levels of fatty acids from palm oil on feed intake and milk production in Holstein cows

To determine the optimum feeding level of fatty acids of palm oil (PALM; Energizer RP10; 86.6% palmitic acid) on milk production, lactating cows (n = 18) were randomly assigned to a treatment sequence in replicated 4 × 4 Latin squares. Animals were assigned to squares by parity (3 multiparous and 1 primiparous squares with primiparous in the incomplete square). The 4 diets were designed to provide 0, 500, 1,000, and 1,500 g of PALM per day. Cows were fed individually with feed intake measured daily. Each period lasted 16 d with milk production and composition determined the final 2 d. Milk production, milk composition and feed intake data were analyzed using the MIXED procedure of SAS. Milk yields were 30.9, 34.0, 34.2, and 34.2 kg/ d (SEM = 1.9) for the 0, 500, 1,000, and 1,500 g levels, respectively. Milk yield was increased by the addition of PALM; however, there were no differences among the levels of PALM. Milk fat percentage was also increased from 3.44% for 0 g to 3.95% (SEM = 0.17) across all levels of PALM but there were no differences among the PALM treatments. Dry matter intakes were 23.3, 26.4, 24.7, and 23.8 kg/d (SEM = 1.4) for the 0, 500, 1,000 and 1,500 g levels, respectively. The addition of PALM increased milk yield and milk fat percentage, and no adverse effects on dry matter intake were observed.