Characterization of Rapeseed Oil Using FTIR-ATR Spectroscopy

Fourier transform infrared attenuated total reflectance （FTIR-ATR） spectroscopy was employed to characterize rapeseed oils. The spectral features of rapeseed oils were first investigated. Spectral data was processed using principal component analysis （PCA） and linear discriminant analysis （LDA） to discriminate the oils from three cultivars of rapeseeds. As a result, 100% discrimination accuracy was obtained by LDA. Furthermore, the applicability of FTIR-ATR spectroscopy to characterize the changes of rapeseed oils caused by thermal treatment was studied. The rapeseed oil at 60 ℃ was regularly subjected to spectral measurement, and the spectral changes induced by thermal treatment were analyzed and discussed. This study had demonstrated the good performance of FTIR-ATR spectroscopy in characterizing rapeseed oils.     

New Process for Extracting Oil and Starch from Tea Seeds

A new process for extracting oil and starch from tea seed was introduced. The new process included one special link compared with all of the processes used now for tea seed oil and starch production. The link was static fermentation by which oil bodies and starch were separated naturally from tea seeds. By the process, tea seed oil and starch which were in conformity with government standards about edible oil and starch were successfully produced with 16% and 8% of production rate, respectively. The new process has many advantages, such as more simple equipments, lower production cost and whole natural products, etc..     

Preliminary Studies on Composition,Quality and Oxidative Stability of Commercial Avocado Oil Produced in Chile

Avocado oil is a relatively new oil in the market and is highly appreciated by the consumers because of its fine aroma, pleasant taste and health benefits. A study on the characterization of commercial avocado oils produced in Chile was conducted in order to discuss their quality parameters. The study was applied to two marketed avocado oils. The main analytical parameters evaluated to the oils were： fatty acid composition, total chlorophylls, total carotenoids, tocopherols, acid value, peroxide value, total phenolic compounds, polar compounds, oil stability, UV absorption and 3.5-stigmastadiene content. The fatty acid compositions of the studied oils were according with oil composition of pulp pure of avocado fruit. The analysis of tocopherols by high performance liquid chromatography （HPLC） revealed significant differences between the avocado oils studied. Total phenolic compounds, oil stability, UV Absorption characteristics, peroxide value, acid value, tocopherols content, total chlorophylls, total carotenoids and polar compounds were also significantly different between the commercial studied oils. All the above results show a different quality between both commercial avocado oils, showing that the sample C has worse values for the parameters of quality as those required by legislation in many countries. Also, 3.5-stigmastadiene content shows high concentration for one of the commercial avocado oil evaluated which demonstrates the presence of refined oil or that the oil has been submitted to high temperatures. On the other hand it is remarkable that despite the fact that there are many differences in quality parameters, both oils are labeled and marketed as extra virgin quality oils, demonstrating the need to regulate the classification of appreciated oils by the consumers.     

Fractionation of Palm Kernel Oil by Short Path Distillation

Fractionation of palm kernel oil （PKO） by short path distillation （SPD） at two feed flow rates （135 g/h and 195 g/h） and six distillation temperatures, TD,s （200, 210, 220, 230, 240 and 250 ℃） was investigated. Other distillation parameters, such as vacuum pressure （0.001 mbar）, blade rotation speed （400 rpm） and temperature of the feed material （60 ℃） were kept constant. The fractionated products, known as residue and distillate, were analysed for physico-chemical properties including fatty acid composition （FAC）, triacylglycerol （TAG） composition, slip melting point （SMP）, thermal analysis by differential scanning calorimetry （DSC） and solid fat content （SFC）. Product yield was measured as well. Crystallisation behaviour of PKO and the fractionated products were studied by measurement of isothermal crystallisation, Tc,. at 0, 5, 10, 15, 20 and 25 ℃. The distillates, collected at all fractionation temperatures, were enriched with caprylic, capric and lauric acids. These fractions were also concentrated with low molecular weight and C36 TAGs. Distillates obtained at higher TDis （230-250 ℃） exhibited higher in SMP and SFC. On the other hand, the residual oils collected at all fractionation temperatures contained higher amount of long-chain fatty acid and palmitic acid. These fractions were enriched with high molecular weight TAGs. Residues obtained at lower Tois （200-220 ℃） were low in SMP and comparable SFC with PKO. Changes in fatty acid and TAG composition resulted in different crystallisation behaviour of the fractions. Distillates collected at all fractionation temperatures crystallised in a sharper peak while residues obtained at higher T Dis （230-250 ℃） showed broader crystallisation peaks, as shown by the DSC thermograms.     

米糠蜡对大豆油凝胶特性的影响研究

在大豆油中添加米糠蜡以制备凝胶油。考察了米糠蜡添加量和冷却温度对凝胶油的影响。结果表明:米糠蜡添加量为8%时,在常温下能形成凝胶油且口感较好,具有一定的塑性。随着米糠蜡添加量的增加,米糠蜡凝胶油在硬度增加的过程中,胶着度下降,弹性和咀嚼度也随之下降,回复性基本不变。此外,在弹性以及黏聚性方面,米糠蜡凝胶油和人造黄油接近。随着米糠蜡添加量的增加,凝胶油的熔融温度和结晶温度升高。     

稻米油在快餐煎炸中的性能研究

本文通过模拟西式快餐门店的煎炸实验,考察了稻米油在快餐煎炸中应用的可行性。通过油脂理化指标、肪酸组成分析及微量成分分析来比较稻米油与棕榈油和大豆油的差异,通过模拟西式快餐门店168℃下煎炸薯条过程中极性物质和酸价的变化,并对薯条进行感官评价,对比稻米油、大豆油与棕榈油的煎炸性能。结果显示:稻米油所含的饱和脂肪酸和不饱和脂肪酸均介于棕榈油和大豆油之间,并且其含有的维生素E与大豆油接近且明显高于棕榈油;另外稻米油还含有12035.74 mg/kg植物甾醇和4359.17 mg/kg谷维素。在煎炸过程中,稻米油的酸价上升速度远远低于大豆油,接近于棕榈油;尽管其初始极性组分较高,但其极性组分在煎炸后期上升比较平稳,至煎炸终点时其极性组分低于棕榈油和大豆油;同时在煎炸过程中,棕榈油、稻米油、大豆油中的维生素E随煎炸时间的延长明显降低,至第6 d对应的含量分别10.01、8.49与2.11 mg/kg;而稻米油中谷维素和植物甾醇含量也随煎炸时间的延长而减少,但至煎炸终点时,仍有较多的保留,含量分别为1531.98和6618.45 mg/kg。另外,感官评价发现,稻米油炸制的薯条比大豆油、棕榈油更酥脆、风味更好,整体喜好度更高。总之,但稻米油具有良好煎炸性能,其煎炸性能明显优于大豆油,可用作西式快餐煎炸油。     

微波处理米糠贮存过程中其油脂酸值变化的研究

采用不同微波方式处理米糠,通过常温贮存试验观察其油脂酸值的变化。结果表明:不同来源的米糠其油脂酸值上升的趋势不同,可能与米糠中酶的活性有关;第1阶段贮存试验中,米糠1#开始2 d内油脂酸值(KOH)增加了3.89 mg/g,米糠3#油脂酸值(KOH)增加了17.4 mg/g,而经微波处理后米糠1#开始5 d内油脂酸值(KOH)仅增加了0.69 mg/g;在第2阶段贮存试验中,未经处理的米糠4#在贮存98 d内油脂酸值(KOH)增加了104.56 mg/g,而经微波处理7的米糠4#油脂酸值(KOH)仅增加了11.97 mg/g,微波处理4的米糠4#油脂酸值(KOH)增加了34.85 mg/g;比较表明微波处理能较好地稳定米糠。     

利用蜂蜡-米糠蜡制备大豆油凝胶油

利用蜂蜡、米糠蜡及其混合物作为凝胶剂,开发大豆油基凝胶油,并将制备的凝胶油与起酥油的物理性质进行比较。通过对2 种添加量下（5%、8%）蜂蜡和米糠蜡（蜂蜡与米糠蜡质量比10∶0、9∶1、8∶2、7∶3、6∶4、5∶5、3∶7、1∶9、0∶10）制备凝胶油的性质测定,结果发现随着米糠蜡比例的增加,凝胶油的硬度（11.9～140.4 g）呈先增加后减小再略有增加的趋势,当蜂蜡与米糠蜡比例为8∶2时,凝胶油的硬度最大,表明蜂蜡和米糠蜡混合后有协同作用;同时析油率采用离心的方法评价,结果发现米糠蜡比例较低（蜂蜡∶米糠蜡＞5∶5）时,凝胶油稳定,析油率为0%,且添加量8%条件下凝胶油的析油率低于普通起酥油。同时固体脂肪曲线、差示扫描量热法结果显示,在10～40 ℃条件下凝胶油的固体脂肪质量分数（8.5%～4%）显著低于起酥油（65%～20%）;融化峰值温度（50.2 ℃）高于起酥油（43.1 ℃）;X射线衍射结果显示8%蜂蜡-米糠蜡（8∶2）凝胶油样品的晶体形态（β’）与起酥油接近,都是细小的结晶。应用发现,蜂蜡与米糠蜡比例为8∶2,添加比例为8%的凝胶油具有较好的烘焙效果,使最终产品的固体脂肪含量大大降低,或许能为消费者拥有更健康的产品提供一条可行途径。     

超临界流体萃取与二乙醇胺法综合制备米糠油

以市购米糠为原料,采用超临界流体萃取法提取米糠油,并对毛糠油的简化精炼工艺进行研究。原料经微波预处理降低解脂酶活性后,利用超临界CO2分段萃取,先后控制条件15MPa、32℃、1.0h和35MPa、40℃、4.0h获得毛糠油Ⅰ、Ⅱ。用二乙醇胺处理毛糠油Ⅱ,通过单因素实验和正交实验得出二乙醇胺法精炼毛糠油的最佳条件为:二乙醇胺加入量为油重的9%,精炼温度为50℃,振荡时间为15min。在此条件下精炼毛糠油,油脂酸价可降至0.85mgKOH/g,酸价降低率达到94.33%。超临界流体萃取与二乙醇胺法精炼综合处理所得米糠油清澈、透明,谷维素含量为1.73%,色度达到了国家标准。     

膳食纤维对油脂、胆固醇、胆酸钠和亚硝酸根离子吸附作用的研究

采用离体实验模拟人体胃和肠道的pH条件,探讨了麦麸、米糠、豆渣、甘薯、大薯、葛根、香芋和马铃薯膳食纤维对油脂、胆固醇、胆酸钠和亚硝酸根离子的吸附能力。结果表明,在酸性条件下清除胆固醇能力最强的是马铃薯膳食纤维,为28.5mg/g;对猪油和中性条件下胆固醇吸附效果最好的是麦麸纤维,分别为1.57g/g和21.6mg/g;对胆酸钠(浓度为3mg/mL和2mg/mL)吸附能力最强的是豆渣膳食纤维,其吸附量分别为143.8mg/g和66.8mg/g;清除NO-2能力最强的是大薯膳食纤维,其清除率在45min后达100%。     

The Potential Application of Rice Bran Wax Oleogel to Replace Solid Fat and Enhance Unsaturated Fat Content in Ice Cream

The development of structure in ice cream, characterized by its smooth texture and resistance to collapse during melting, depends, in part, on the presence of solid fat during the whipping and freezing steps. The objective of this study was to investigate the potential application of 10% rice bran wax (RBW) oleogel, comprised 90% high‐oleic sunflower oil and 10% RBW, to replace solid fat in ice cream. A commercial blend of 80% saturated mono‐ and diglycerides and 20% polysorbate 80 was used as the emulsifier. Standard ice cream measurements, cryo‐scanning electron microscopy (cryo‐SEM), differential scanning calorimetry (DSC), and transmission electron microscopy (TEM) were used to evaluate the formation of structure in ice cream. RBW oleogel produced higher levels of overrun when compared to a liquid oil ice cream sample, creating a lighter sample with good texture and appearance. However, those results were not associated with higher meltdown resistance. Microscopy revealed larger aggregation of RBW oleogel fat droplets at the air cell interface and distortion of the shape of air cells and fat droplets. Although the RBW oleogel did not develop sufficient structure in ice cream to maintain shape during meltdown when a mono‐ and diglycerides and polysorbate 80 blend was used as the emulsifier, micro‐ and ultrastructure investigations suggested that RBW oleogel did induce formation of a fat globule network in ice cream, suggesting that further optimization could lead to an alternative to saturated fat sources for ice cream applications.     

米糠油的物理精炼工艺与实践

概述了米糠油的物理精炼工艺,对米糠油物理精炼工艺中各工序的操作过程、参数、使用设备进行了详细地叙述,并对采用物理精炼工艺生产国标一级米糠油过程中出现的问题进行分析,提出了解决方法.生产实践表明,使用酸值为22 mgKOH/g毛米糠油生产国标一级米糠油的成品油得率为75.3%;采用物理精炼工艺是高酸值米糠油精炼的最佳选择.     

一级米糠油生产工艺的研究

本文对生产一级米糠油工艺进行了研究，采用糠粞分离和米糠挤压膨化工艺，有利于米糠原油质量的提高。利用物理精炼技术对高酸价米糠原油进行脱酸，使油脂损耗显著降低。米糠油脱蜡和分提是精炼一级米糠油较重要的过程。本工艺实际生产结果表明，一级米糠油符合国家标准，同时成品油得率比传统工艺生产的得率提高了12％以上。     

稻米胚及米胚油的品质分析

从原料米糠中分离出纯稻米胚和纯米糠,利用溶剂浸出法分别提取其中油脂并进行品质分析对比,以研究稻米胚及米胚油的营养品质。结果表明:稻米胚粗脂肪含量27.06%,粗蛋白含量19.50%,粗纤维含量4.88%,比米糠粗脂肪、粗蛋白含量明显提高,粗纤维含量降低;米胚油的酸值(KOH)、过氧化值、维生素E含量、谷维素含量、植物甾醇含量分别为21.7 mg/g、6.1 mmol/kg、43.18 mg/100 g、0.47%、3.07%,与米糠油相比,米胚油的酸值(KOH)降低了23.8 mg/g,过氧化值降低了1.7 mmol/kg,维生素E含量提高了17.18 mg/100 g,植物甾醇含量相差不大,谷维素含量降低0.93个百分点。米胚油在酸值和维生素E含量方面较米糠油具有明显优势,新鲜稻米胚既可以直接作为营养丰富的产品,也是优质食用油的原料。     

挤压稳定化对不同贮藏时间米糠制备米糠毛油品质的影响

以不同贮藏时间的米糠为原料,研究米糠挤压稳定化处理对米糠毛油品质的影响。结果表明:相比米糠未稳定化制备的米糠毛油,米糠挤压稳定化处理增加米糠毛油的酸值和过氧化值;随着米糠贮藏时间的延长,米糠挤压稳定化处理与未稳定化处理制备米糠毛油酸值和过氧化值相差幅度增加;米糠挤压稳定化处理对米糠毛油的脂肪酸组成影响较小,仅亚麻酸含量显著下降,米糠挤压稳定化处理对米糠毛油碘值和皂化值没有显著影响;米糠挤压稳定化处理显著降低米糠毛油磷脂、水分及挥发物含量,随着米糠贮藏时间的延长,米糠挤压稳定化处理与未稳定化处理制备米糠毛油磷脂含量相差幅度增大;此外,米糠挤压稳定化处理可显著提高米糠毛油谷维素含量。     

谷维素对3种食用植物油的抗氧化效果研究

从米糠油皂脚中提取纯化谷维素,按不同比例添加到大豆油、菜籽油和油茶籽油中,分别采用Schaal烘箱法和油脂氧化分析仪对3种植物油氧化稳定性进行测定,同时考察在植物油氧化过程中,谷维素对其脂肪酸组成的影响,并与常见的油脂抗氧化剂进行对比。结果表明:油脂中分别添加0.1%和0.5%谷维素均对大豆油、菜籽油和油茶籽油的氧化诱导期具有延长作用,其中对油茶籽油的作用最显著;在Schaal烘箱实验中,谷维素能够有效延缓大豆油和油茶籽油过氧化值的升高,并且对油中多不饱和脂肪酸的氧化有抑制作用,但对菜籽油的抗氧化作用不显著。     

EFFECT OF BLENDING ON SENSORY ODOR PROFILE AND PHYSICO-CHEMICAL PROPERTIES OF SELECT VEGETABLE OILS

Edible oils of common use in households are mainly of vegetable origin. The present trend of globalization and emphasis on nutritional enrichment has led to the exploration of usage of blended oils. Binary blends studied in this work consisted of 80% base oil (mustard, groundnut and sunflower oil) and 20% blending oil (sesame, refined palm and rice bran oil). The sensory odor profiling of base oils, namely sesame blending oils and their blends was monitored by Sniff test method. The characteristic notes of mustard oil were more of sulfury, pungent and sour while that of palm oil was more husk-like; sesame oil, seedy and earthy notes; rice bran oil was branny, earthy and groundnut oil more nutty, and had a fresh oil-like note on the profilogram. Profilogram of blends showed a decrease in the intensities of dominating notes of the base oils. The color measurement of blended oils showed variation in L*, a*and b*values with a⁺(redness) for refined palm oil blends, b⁺(yellowness) for sesame and mustard oil blends and a^-(greenness) for rice bran oil blends. The sensory color perception values and CIE color values for L*, a*and b*were negatively correlated for lightness (L*) and sensory redness color values (r=-0.67; p<0.05), while a positive correlation existed between a*and sensory redness values (r=0.72; p<0.05). The apparent viscosity of the oil blends indicated a pseudoplastic shear thinning behavior. The apparent viscosity of the base oils increased when blended with sesame or rice bran oil, while it decreased upon blending with refined palm oil.     

米糠油氧化稳定性研究及货架期预测

以精炼米糠油为原料,通过分析其理化指标与脂肪酸组成,探讨贮藏条件对米糠油氧化稳定性的影响,建立氧化反应动力学方程,预测米糠油的货架期。结果表明,米糠油脂肪酸中不饱和脂肪酸含量为77.45%,主要有棕榈酸17.77%、油酸46.74%、亚油酸29.34%。米糠油的氧化稳定性受光照、温度和氧气含量的影响,空气中氧气的存在会加速米糠油氧化,温度越高,氧化速度越快;不同光照条件下的稳定性依次为:避光>紫外光>自然光>日光灯。米糠油氧化遵循一级化学反应,其动力学模型为RTk e796.360.3564=,通过外推法得出米糠油20℃、25℃和30℃的货架期分别为1068 d、410 d、206 d。     

米糠蜡添加量对亚麻籽油基油凝胶结构及性质的影响

为探究亚麻籽油基油凝胶作为替代传统塑性脂肪的潜力,以米糠蜡为凝胶剂,探究不同米糠蜡添加量对亚麻籽油基油凝胶外观形态、微观结构、持油率、理化性质及热力学性质的影响。结果表明：在室温条件下,米糠蜡添加量不小于6%时才会使亚麻籽油凝胶化;随着米糠蜡添加量的增加,油凝胶的结晶网络结构由簇状逐渐转变为针状,结晶密度增大;油凝胶的持油率、酸值以及熔融峰/结晶峰峰值温度均随着米糠蜡添加量的增加而增大;油凝胶的过氧化值随着米糠蜡添加量的增加呈现先增后减的趋势。综上,在亚麻籽油中添加适量的米糠蜡可形成热塑性好、结构稳定、理化性质良好、持油率高的油凝胶。     

Characteristics of low-fat meat emulsion systems with pork fat replaced by vegetable oils and rice bran fiber

The effects of vegetable oils prepared from olive, corn, soybean, canola, or grape seed, and rice bran fiber on the composition and rheological properties of meat batters were studied. Pork fat at 30% in the control was partially replaced by one of the vegetable oils at 10% in addition to reducing the pork fat to 10%. The chemical composition, cooking characteristics, texture properties, and viscosity of low-fat meat batters were analyzed. The moisture, protein, ash content, uncooked and cooked pH values, b^∗-value, hardness, cohesiveness, gumminess, chewiness, and viscosity of meat batters with vegetable oil and rice bran fiber were all higher than the control. In addition, batters supplemented with vegetable oil and rice bran fiber had lower cooking loss and better emulsion stability. Low-fat meat batters with reduced pork fat content (10%) and 10% vegetable oil plus rice bran fiber had improved characteristics relative to the regular fat control.