棕榈油干法分提条件研究

以碘价为54棕榈油为原料,采用干法分提制备棕榈油中间熔点物(POMF)。在单因素试验基础上,采用响应面优化实验,研究结晶温度、冷却速率和养晶时间对干法分提效果影响。得出棕榈油干法分提最佳工艺条件为:结晶温度16.83℃,冷却速率1.31℃/h,养晶时间13.39 h。在此条件下棕榈油中间熔点物(POMF)得率为30.3%,熔点为35.0℃,熔程为32℃³6℃。实验测定结果为:棕榈油中间熔点物(POMF)得率为29.9%,熔点为35.3℃,熔程为32℃36℃。实验测定结果为:棕榈油中间熔点物(POMF)得率为29.9%,熔点为35.3℃,熔程为32℃³6℃。     

棕榈油干式分提的应用和进展

干式分提是油脂物理改性过程,可得到高碘值的棕榈油（IV65和IV71）和高饱和度的棕榈硬脂。随着结晶罐结构（带超冷）的改进和膜式过滤机的使用,缩短了结晶时间,提高了液体油的得率和硬脂的纯度,使用PLC系统可准确控制结晶过程和过滤过程,降低分提成本。     

棕榈油干法分提的工艺实践与研究

采用干法分提工艺对棕榈油进行分提,通过实践分析了工艺中结晶设备、原料组成、冷却状况、晶体异构对冷却结晶过程的影响,研究了压滤过程中的影响因素,给出了相关的技术参数,以期为实际生产提供指导和参考.     

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.     

缩短棕榈油干法分提结晶时间的探索与应用

对棕榈油干法分提工艺进行了改进,将棕榈油结晶过程由不分时间段的持续降温改为分若干个时间段的快速降温、恒温、慢速降温的阶段式结晶方式,并对该改进工艺和主要设备性能进行阐述。实践表明,该改进工艺可以缩短结晶时间,降低能耗,提高生产效率,而且有利于保持产品质量的稳定。     

棕榈油干式分提工艺结晶回温的原因及解决办法

简要说明了棕榈油干式分提工艺结晶回温的害处,并详细分析了回温的原因。回温是由于RBD棕榈油熔点偏高或偏低,或者是结晶菜单不适合造成的。针对不同的回温原因,分别提出了不同的解决办法:当RBD棕榈油熔点偏低时,结晶菜单主结晶段设置温度应下调、时间应减少;当RBD棕榈油熔点偏高时,结晶菜单主结晶段设置温度应上调,时间应增加;当结晶菜单设置不合适时,可归类于RBD棕榈油熔点偏低或偏高进行调整。     

棕榈油的分提方法

棕榈油的分提方法有:干法分提、溶剂分提及表面活性剂分提.综述了这三种方法的原理及加工条件,尤其是干法分提工艺及设备.     

棕榈油中间分提物(PMF)在冰淇淋中应用研究

通过对棕榈油中间分提物(PMF)理化性质分析,表明棕榈油中间分提物理化性质能满足生产冰淇淋要求,并用此特定油脂进行冰淇淋配方研究,确定PMF油基冰淇淋最佳配方:PMF添加量为6%、脱脂乳粉添加量为8%、糖添加量为13%、乳化剂添加量为0.5%、稳定剂添加量为0.2%。     

Physical,chemical and stability properties of buffalo butter oil fractions obtained by multi-step dry fractionation

Chemical, physical and stability properties of buffalo butter oil fractions, obtained by stepwise crystallization at several temperatures between 15 and 40 °C, were investigated. Saponification, iodine, Reichert-Meissl, Polenske and Krishner values of low-melting fractions (LMF) were significantly higher (P<0.05) than high-melting fractions (HMF) or the original butter oil. Cholesterol, fat-soluble vitamins (A, D and E) and lactones tended to concentrate more in LMF than middle-melting fractions (MMF) and HMF. Refractive index and specific gravity of MMF lie between those of LMF and HMF. LMF showed the lowest stability toward thermal oxidation (5.6 h) when compared to MMF (7.7–11.2 h) and HMF (11.1–16.0 h). Rate of hydrolysis of LMF was the highest (7.8 ml of 4 g/l NaOH) among all the obtained fractions, while HMF was the lowest (4.9–1.6 ml of 4 g/l NaOH). Differences in chemical and physical properties of the fractions were attributed to differences in fatty acid composition.     

Crystallization kinetics of palm oil in blends with palm-based diacylglycerol

Crystallization kinetics of palm oil (PO) in the presence of different concentrations (2, 5, 10, 30 and, 50% w/w) of palm-based diacylglycerol (PB-DAG) were investigated over different ranges of crystallization temperatures. Addition of 30 and 50% (w/w) of PB-DAG (high concentrations) increased significantly (P < 0.05) the melting point and crystallization onset while addition of 2 and 5% PB-DAG did not have significant (P > 0.05) effect. PO and PO blends with 2 and 5% of PB-DAG showed crystal transformation at crystallization temperatures (T_Cr) of 26, 26, 26.5 °C, respectively as reflected in corresponding changes of the Avrami parameters at below and above these T_Cr. This was especially evident for the blends containing 2 and 5% of PB-DAG. Individual comparison of induction time (T_i), Avrami exponent (n), Avrami constant (k) and half-time of crystallization (t_1/2) of blends classified under various supercooling ranges based on the supercooling closeness (± 0.1 °C), showed that addition of 5% of PB-DAG in most of the supercooling ranges significantly (P < 0.05) reduced nucleation rate as well as crystal growth velocity of PO. This was reflected in the significantly (P < 0.05) higher T_i and t_1/2 and lower k. Although the presence of 2% of PB-DAG was found to have inhibitory effect on PO crystallization, this effect was not significant (P > 0.05). Mode of crystal growth attributed to n was changed significantly only in presence of 5% of PB-DAG. Furthermore, presence of 10% PB-DAG showed ??'-stabilizing effect on PO. On the other hand, high concentrations of PB-DAG were found to significantly (P < 0.05) reduce T_i as well as t_1/2 and also increase k suggesting their promoting effects on nucleation and crystallization rate of PO even with the close supercoolings. In addition, they changed crystal growth mode of PO. Amongst the different concentrations of PB-DAG investigated, blend containing 50% of PB-DAG as compared to PO, not only, have healthier benefits but also, may have greater potential applications in plastic fat products due to its unique physical properties.     

棕仁原油在温度梯度场中的结晶动力学研究

以棕仁原油为研究样品,借助于自行开发的试验装置,研究样品在不同温度梯度场中的结晶行为,得出晶体生长速率Rg以及结晶效率Y的变化规律并观察其晶体形态;同时借助于Avrami方程对试验数据进行模拟,得出确切的结晶动力学参数,如晶体形态n、结晶速率k、结晶半周期t1/2等,并采用双对数图对Avrami方程的拟合程度进行检验,以确定Avrami模型的适用性。     

Crystallization and rheology of palm oil in the presence of sugar

Palm oil is an alternative to partially hydrogenated vegetables oils for fat-based confections given its semi-solid consistency and zero trans fat content. However, its slow crystallization behaviour results in hardening during storage and an objectionable texture. While there are numerous studies on palm oil solidification and storage properties in bulk, the impact of sugar in this context has yet to be reported. In this study, the crystallization and rheology of two commercial palm oils in both bulk and mixed 1:1 (wt.%) with confectioner's sugar were explored over four weeks of storage. The palm oil with the higher diacylglycerol and saturated triacylglycerol content experienced significantly higher solid fat contents and viscous/elastic moduli with storage time. The presence of sugar reduced the solid fat content of both palm oils, but increased their solid-like character, an effect we ascribed to the role of the dispersed sugar on oil viscosity. Principal component analysis on lipid composition identified the key species contributing to these properties. These findings establish a foundation for the optimization and improvement of palm-based confections.     

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.     

Preservation of oil palm fruit and oil palm fruit mesocarp by gamma irradiation

Experiments were conducted to determine the potential of gamma radiations in the extension of the shelf-life of oil palm fruit and oil palm fruit mesocarp. In the course of the experiment, it was observed that even though palm fruits in their harvested form, went bad within 3 days post-harvest, their shelf-life can be extended to at least 2 months through preparation of dry oil palm fruit mesocarp. Furthermore, despite the fact that gamma radiation cannot be used to prolong the shelf-life of oil palm fruit proper, it can be used to drastically reduce the mould load in the dry palm fruit mesocarps, thereby further enhancing their keeping quality and consumer acceptance. Chemical and organoleptic analyses of fat extracted from irradiated, dry oil palm fruit mesocarp show that there is practically no radiation effect. The significance of these observations is discussed in relation to the possible acceptance of radiation-preservation of oil palm fruit mesocarp commercially.     

棕榈油大豆油为原料调和油冷冻性能研究

对碘值60棕榈油与大豆油调和而成调和油在0℃、10℃、20℃三种温度条件下进行冷冻性能研究。在0℃情况下,即使棕榈油含量仅10%,也会很快混浊和结冻;在10℃情况下,含20%棕榈油的棕榈油大豆油调和油可保持15天以上澄清透明;在20℃情况下,含40%棕榈油的棕榈油大豆油调和油可保持25天以上而澄清透明。     

棕榈油和棕榈仁油的地位和现状

中国是一个油脂资源非常贫乏的国家 ,每年都要从国外进口大量的油脂以满足人民生活及工业需要。据统计 ,1997年中国进口的大豆油是 2 0 0万吨 ,棕榈油 16 2万吨 ,棕榈仁油 1 5万吨 ,其中棕榈油的消费量已位居第 4(见表 2 )。预计 ,至 2 0 0 5年 ,世界棕榈油的消费量将超过大豆油 (见表 1)。作为具有巨大市场潜力和价值的油脂资源 ,国外就棕榈油和棕榈仁油的生产、物理和化学性质及其应用等方面的研究已日趋深入[1] ,但在我国有关棕榈油和棕榈仁油的研究和介绍资料极少。为此 ,希望通过本文的介绍 ,能加深对棕榈油和棕榈仁油的了解 ,并能引起…     

超声波处理对棕榈油性质影响

该文以精炼棕榈油为原料,研究不同条件超声波处理对棕榈油感官性质、酸值、过氧化值影响规律。结果表明:超声波作用导致棕榈油中产生絮状物质,且随超声功率增大,絮状物增多。超声波处理后棕榈油酸值与未处理油的酸值相比无显著差异。随贮存时间延长、功率增加、超声时间增加,棕榈油过氧化值呈递增趋势,但在实验条件下,过氧化值均未超过食用精炼棕榈油质量标准。     

Evaluation on some finishing properties of oil palm plywood

Oil palm is the largest and most important plantation crop in Malaysia. The oil palm generally lasts for 25–30 years before the next replantation is done. Substantial amount of biomass in the form of palm trunk results from plantation cycle. This resource is simply left on the ground to decay and is not used as raw material to manufacture any kind of value-added products. The objective of this study was to investigate the possibility of manufacturing plywood from oil palm trunks and to evaluate some of the finishing properties of such experimental panels in comparison to those from Shorea sp as control samples. Three-ply plywood samples were produced from 5 mm thick veneers of oil palm using urea formaldehyde adhesive. Three types of chemicals, namely nitrocellulose, pre-catalyzed lacquer and polyurethane were used to finish experimental panels. The surface finished with nitrocellulose had the lowest contact angle on raw surface of oil palm plywood and wood. The average cross cut tape index of oil palm plywood was comparable to Shorea sp. All finishing materials of oil palm plywood produced impact rating of 4 except for surface finished with nitrocellulose while finishing on wood indicated an impact rating of 3. Oil palm plywood had higher weight loss compared to Shorea sp. Based on results from contact angle, cross cut tape index, impact rate test, weathering, and soil burial test methods it appears that the samples showed acceptable finishing properties comparable to those of solid wood.