脱色吸附剂对大豆脱色油返酸返色的影响

为对油脂精炼脱色加工提供参考,以活性白土、凹凸棒土以及二者复配作为脱色剂对大豆中和油进行脱色,测定脱色油的酸值、色泽,并通过返酸返色试验探究脱色吸附剂对大豆脱色油返酸返色的影响。结果表明：脱色油酸值与活性白土添加量和复配脱色剂中活性白土质量分数呈正相关,与凹凸棒土添加量呈负相关;脱色剂添加量越多,脱色效果越明显,但在活性白土或凹凸棒土添加量超过3%时,脱色效果增加较少;随活性白土或凹凸棒土添加量的增多,脱色油返酸总体呈先降后升趋势;脱色油会有不同程度的返色,与活性白土相比,凹凸棒土脱色返色程度更高。综上,在脱色过程中,通过调整脱色剂添加量和配比可在一定程度上控制成品油的返酸返色程度。     

蒙脱土对植物油脱色效果的综合评价北大核心CSCD

为了开发高效、环保的食用油脱色剂,以一种环保方法(半干法)生产的蒙脱土为研究对象,研究其在不同脱色条件(脱色温度、脱色时间和脱色剂添加量)下对大豆油、葵花籽油和菜籽油品质的影响。结果表明:该蒙脱土具有吸附色素和过氧化物从而降低油脂红值和过氧化值的作用,与脱色前相比,大豆油、葵花籽油和菜籽油的红值最大降幅分别为77.4%、92.3%和87.2%,过氧化值最大降幅分别为82.7%、83.2%和91.2%;蒙脱土用于3种植物油的脱色,植物油中总甾醇和总生育酚含量下降,而酸值总体上缓慢上升。进一步研究发现,在相同的脱色条件下,蒙脱土对大豆油、葵花籽油和菜籽油的酸值、总甾醇含量和吸油率的影响结果均优于活性白土,尤其是吸油率几乎是活性白土的一半。蒙脱土可替代活性白土用于对色泽要求不是很高的植物油脱色中。     

Carbonaceous materials from seed hulls for bleaching of vegetable oils

Seed hulls, namely cottonseed, peanut, sunflower, soybean, faba bean and lupine were evaluated as carbonaceous materials for the bleaching of crude soybean oil. The six seed hulls were activated by carbonization, steam activation and acid activation. Two reference standards, Fullers earth and Tonsil clay, were used for comparison throughout the whole study. Bleaching of crude soybean oil under vacuum at 100 °C using the treated hulls was carried out. The effect of bleaching with the different hulls on the oil characteristics was evaluated by determining the % free fatty acid, % reduction in peroxide value, % removal of phospholipids, % bleachability and oxidative stability of the bleached oils. Results revealed that bleaching with carbonized hull yielded oils with least free fatty acid content and highest oxidative stability. Bleaching with acid activated hull carbons gave oils with least content of peroxides, phospholipids together with best color. Acid activation of the hulls resulted in highest increase in surface area, pore volume and least pore dimension.     

大豆油生产加工中色泽控制措施

一些大豆油含特殊杂质和色素,在脱色过程中白土用量过高,成品油氧化稳定性差。为了防控大豆油制取和精炼过程中色泽加深,降低白土用量,可采取不同的措施:预处理过程中调整参数让部分色素固化,浸出过程中采取多级过滤,降低蒸发和汽提温度,改造汽提塔结构以减少加工色素;精炼过程依据小样实验取得毛油品质数据调整操作参数,对部分脱色设备进行改造。生产精炼包装油按酸价(KOH) 0. 05 mg/g,色泽Y5～6/R0. 5～0. 6;散装油酸价(KOH) 0. 07～0. 08 mg/g,色泽Y7/R0. 7。储备大豆油和酸价(KOH) 2～3 mg/g毛油的脱色白土消耗量在原17～24 kg/t的基础上平均降低30%,包装油的货架期也明显延长。     

Solid Phase Microextraction of Volatile Soybean Oil and Corn Oil Compounds

ABSTRACT: The qualitative and quantitative determination of volatile compounds in soybean and corn oils were analyzed by solid phase microextraction. Coefficients of variation and sensitivity of polydimethylsiloxane, carboxen/polydimethylsiloxane, polyacrylate, and carbowax/divinylbenzene for hexanal analysis in soybean oil were 3.2, 4.2, 7.2, and 10.7%, and 15, 30,20, and 10 ppb, respectively. Volatile compounds of soybean oil with peroxide value (PV) of 1 or 5 were extracted by polydimethylsiloxane at 60 °C for 60 min. The amount of volatile compounds of PV 5 soybean oil was 92% higher than the PV 1. Volatile compounds including 2,4-decadienal, 2-decenal, hexanal, and pentane were identified in soybean and corn oils by SPME-GC-MS and GC retention time. SPME was a simple, reproducible and sensitive method for the analysis of volatile compounds of vegetable oils. Keywords: solid phase microextraction, headspace volatile compounds, soybean oil, corn oil     

Effects of Bleaching on the Properties of Roasted Sesame Oil

ABSTRACT: Improvement in quality of roasted sesame oil was studied. Roasted sesame oil was bleached at 70 °C, 85 °C, or 100 °C for 20 min with acid-activated clay at 0.5%, 1.0%, or 3.0% (w/w) and then centrifuging at 12096 × g at 4 °C for 10 min. The color of the roasted sesame oil became lighter and the viscosity of oil decreased by bleaching. Bleaching caused a significant increase in the smoke point of the oil, from 170 °C to a range of 183 °C to 191 °C. Bleaching increased palmitic acid and decreased linoleic acid contents of roasted sesame oil. Bleaching decreased free fatty acid (FFA) and conjugated dienoic acid (CDA) contents and carbonyl values (CV) of roasted sesame oil. The more the acid clay was used, the lower were the FFA and CDA contents and CV of the oil. Amount of acid clay in bleaching of roasted sesame oil had higher effects on the color, viscosity, smoke point, FFA and CDA contents, and CV of roasted sesame oil than the bleaching temperature. Bleaching did not show a significant effect on tocopherol contents of the sesame oil. Bleaching tended to decrease sesamolin contents and increase sesamol contents in the roasted sesame oil. As the amount of acid clay and the bleaching temperature increased, the contents of sesamin and sesamolin in the oil decreased while sesamol contents increased.     

响应面试验优化油脂分段脱色工艺

利用多次吸附平衡可有效降低油脂的色泽原理,采用单因素试验探究分段脱色工艺对大豆油脱色效果的影响,然后通过响应面法获得最佳脱色工艺参数。在添加总量一定时,将活性白土分3 段进行添加,通过改变每段添加量比例,确定最佳吸附平衡的条件;在搅拌速率为150 r/min时,活性白土添加总量1.27%、脱色温度100 ℃、脱色总时间60 min,脱色油脂酸值为0.12 mg KOH/g,过氧化值为3.26 mmol/kg,色泽为黄18、红1.45,相对于常规脱色工艺活性白土用量减少9.29%,提高了油脂的精炼率。     

Designing of high voltage electric field for soybean and sunflower oil bleaching

To the best of our knowledge, this work for the first time in the world carried out at the Tarbiat Modares University. In the present research, high voltage electric field (HVEF) method was utilized for bleaching of soybean and sunflower oil. For optimization of the bleaching process, the effect of different independent variables such as clay percentage (0.5–2%), voltage (0–24 kV), distance (8–12 mm), different numbers of cathode–anode (4–8) and inert-electrolyte (HCl; 0–50 mM) was studied. In order to compare the properties of the bleached samples using HVEF and control (industrial condition) bleaching methods, the indexes of Lovibond, Hunter lab, carotenoid, chlorophyll, bleaching efficiency (BE), peroxide (PV), tiobarbituric acid (TBA), free fatty acid (FFA), tocopherol, sterol and fatty acid composition were measured. According to the results, the BE value of HVEF technique in bleached soybean (88.35%) and sunflower oil (75.41%) were higher in comparison with the soybean (85.80%) and sunflower (58.14%) oils bleached using control method. Consequently, the HVEF bleaching method seems to be an alternative to the industrial method as it reduced clay percentage (50 and 66%), temperature (28% and 28%) and process time (35% and 35%) in soybean and sunflower oil bleaching, respectively.Industrial relevanceHigh voltage electric field (HVEF) method for bleaching of soybean and sunflower oil was done, for the first time in the world to the based of our knowledge, and was optimized under different conditions including clay percentage (0.5–2%), voltage (0–24 kV), distance (8–12 mm) with different numbers of cathode–anode (0–8), inert electrolyte (HCl; 0–50 mM). HVEF could be an alternative for bleaching method in the oil industry; HVEF could reduce %clay, temperature and time consumption in oil industry with low energy consumption; HVEF could produce micro and Nano clay by pulsed corona and pulsed spark type systems.-To Patent No: A23D; C11B; C11C; H03, “Design of high voltage electric field for the oil bleaching”, Tehran-Iran (2015).     

氧化和还原漂白对大豆纤维结构性能的影响

还原漂白的大豆纤维白度和失重率很低，还原漂白对大豆蛋白含量和微细结构无影响、对可染性的影响很小。在氧化漂白中，亚氯酸钠和双氧水／四乙酰乙二胺(反应生成过乙酸)的漂白效果很好；亚漂纤维的失重率高、大豆蛋白含量降低较大，漂白时大豆蛋白的流失极大地降低了可染性；双氧水/四乙酰乙二胺和双氧水漂白的纤维失重率低、大豆蛋白含量稍有降低，两者(尤其是前者)对碱性和羟基氨基酸的可能的氧化作用导致了可染性的降低。氧化和还原漂白对纤维的结晶特性几乎无影响。     

凹凸棒石油脂脱色行为及其机理

以凹凸棒石为大豆油脱色吸附剂,通过对其物理特性、脱色热力学和吸附动力学分析,探讨凹凸棒石吸附剂的吸附行为与脱色机理。结果表明,凹凸棒石吸附剂主要为短晶束和单晶形,其孔径集中分布于1.5～10.0?nm的范围内;脱色热力学分析表明,随着脱色温度升高,凹凸棒石的色素吸附能力逐渐增强,但温度不能改变吸附剂对色素类物质的作用方式;吸附动力学分析表明,叶绿素等微量成分在凹凸棒石上的吸附速率较快,正己烷纯溶液体系中吸附速率依次为叶绿素＞亚油酸＞磷脂＞类胡萝卜素,而大豆油体系中吸附速率依次为叶绿素＞类胡萝卜素＞游离脂肪酸＞磷脂。由此可知,凹凸棒石油脂脱色主要通过孔径填充吸附,并伴随有部分氢键吸附和化学吸附。     

Identification of 2-Pentyl Furan in Fats and Oils and Its Relationship to the Reversion Flavor of Soybean Oil

SUMMARY— 2-Pentyl furan is identified as a component of the volatile decomposition products of slightly autoxidized soybean and cottonseed oils and those of thermal oxidation of corn oil and hydrogenated cottonseed oil. The flavor threshold of this compound in oil at room temperature is 1 ppm. At concentrations of 1-10 ppm, it imparts to the oil a characteristic beany odor and flavor reminiscent of those of a reverted soybean oil. Expert organoleptic panels consistently identified a deodorized cottonseed oil containing 5 ppm of 2.pentyl furan as a reverted soybean oil. It is proposed that this compound is formed by autoxidation of linoleic acid.     

Antioxidant activity,fatty acids and phenolic acids compositions of potato peels

The effects of freeze-dried extracts from the peels of six potato varieties as antioxidants in pure soy oil were investigated using the active oxygen method (AOM) procedure, carotene bleaching and linoleic acid oxidation experiments on thin-layer chromatography (TLC) plates. At 9 h under AOM conditions, 20 g soy oil treated with 0.05 g of these extracts attained lower peroxide values (PV, 22.0-28.0 meq kg^?1) than the control oil sample (PV, 109.0 meq kg^?1) indicating very strong antioxidant activities. Oils treated with the same amount of tertiary butylhydroquinone, butylated hydroxyauisol-butylated hydroxytoluene mixture and rosemary extract attained PV of 10, 19.0 and 16.0 meq kg^?1, respectively. Results of the carotene bleaching and linoleic acid oxidation experiments on TLC plates indicated that the antioxidant activities of these extracts were due to the presence of phenolic acids. Among the phenolic acids separated and identified by both high-performance liquid chromatography and TLC, chlorogenic, proto-catechuic and caffeic acids were predominant and appeared to be mainly responsible for the strong antioxidant activities of the extracts. Peels from the red potatoes contained more polyphenols than those from the brown-skinned varieties, but their oil contents were similar.     

菜籽油中掺入大豆油后的鉴别方法初探

通过对不同菜籽油的亚油酸与油酸组分之比进行分析得出一个范围值,在加入不同量的大豆油后,对两组分比进行再次分析,根据比值确定掺入大豆油的量,最终确定较可靠的掺入大豆油的检出量。     

油脂脱色过程对游离脂肪酸影响研究

大豆油中所含游离脂肪酸（简称FFA）主要是亚油酸,亚油酸的两个双键之间含有一个活性很强的亚甲基,油脂脱色使用的脱色剂对该亚甲基参与的许多反应是天然的催化剂,本论文通过实验测定了脱色温度、时间、用量对FFA含量的影响.     

Effects of different filling media on the oxidation and lipid quality of canned silver carp (Hypophthalmichthys molitrix)

The influence of four different filling media (sunflower oil, soybean oil, olive oil and brine) on the oxidation and lipid quality of canned silver carp was evaluated. Hydrolytic rancidity showed that free fatty acid contents in brine and soybean oil canned muscle were higher than olive oil or sunflower oil canned samples. Conjugated diene (CD) levels in soybean oil canned samples increased but the highest CD values were found in canned silver carp using brine as filling medium. Except for olive oil canned muscle, significant increase in thiobarbituric acid (TBA) values was obtained. The highest TBA value was observed in soybean oil canned sample. Canning led to exchange of fatty acids between the fat in the silver carp muscle and the filling media used. Results indicate that the fat composition of canned silver carp tends to be similar to that of the fat used as filling media.     

电化学氢化法制备低反式脂肪酸大豆油脂

设计了质子转移膜式电化学氢化反应器,在低温（30-75 ℃）、常压和低电流密度下实施大豆油氢化反应,反应以稀甲酸钠溶液作为介质,通过电化学方法使甲酸根离子再生并作为电化学氢化反应媒质。考察电化学氢化反应条件反应温度、机械搅拌强度、EDDAB量和溶液组成对氢化油脂脂肪酸组成、碘值、反式脂肪酸含量、异构化指数和氢化反应选择性的影响。结果表明,质子转移膜式电化学氢化法制备氢化大豆油的最适工艺参数为反应温度60 ℃,机械搅拌强度850 r/min,3.0 g EDDAB /100 g油,溶液组成0.3 g/g,在此条件下获得碘值为82.73 g I2/100 g油,TFAs含量为13.3%,酸值为0.15 mg KOH/g油,过氧化值为0.070 g/100 g油的氢化大豆油产品。与传统气体氢化工艺相比,当完成相同程度氢化时,质子转移膜式电化学氢化可使反式脂肪酸含量减少71％。     

Effects of Fatty Acid Composition and β‐Carotene on the Chlorophyll Photosensitized Oxidation of W/O Emulsion Affected by Phosphatidylcholine

Abstract: Chlorophyll photosensitized oxidation of W/O emulsion consisting of oils with different fatty acid composition was studied and β‐carotene effects on the singlet oxygen oxidation affected by phosphatidylcholine were evaluated by determining peroxide value (PV) and conjugated dienoic acid (CDA) contents. An emulsion was composed of purified oil (sunflower, soybean, canola, or olive oil), water, and xanthan gum (50:50:0.35, w/w/w) with addition of phosphatidylcholine (0 or 250 ppm) and β‐carotene (0, 1, 5, or 10 ppm). PV and CDA content of oil in the emulsion were increased with time under chlorophyll photosensitized oxidation, and the oxidation rate was higher in the emulsion consisting of sunflower or soybean oil whose polyunsaturated fatty acids content was high compared to canola or olive oil. Addition of β‐carotene to the emulsion significantly decreased the oil oxidation under chlorophyll photosensitization, however, co‐addition of phosphatidylcholine decreased the antioxidant activity of β‐carotene, suggesting an antagonistic antioxidation between them. Practical Application: The results of this study can be applied to the area of emulsion foods such as salad dressing to have improved texture and stability by decreasing the oil oxidation and providing desirable color by use of β‐carotene with phosphatidylcholine as emulsifier.     

Comparative study of soybean oil refining using rice hull silicate and commercial adsorbents

To obtain an edible grade of soybean oil, impurity removal processes are important steps in refining. To remove coloring compounds and free fatty acids, commercial adsorbents (silica gel, activated carbon, aluminum oxide, alumina silicate, acid clay, and zeolite) and rice hull silicate (RHS) were evaluated with respect to their adsorption removal efficiencies for lutein. Various doses of commercial adsorbents and RHS were individually added to degummed soybean oil to remove lutein. The commercial adsorbents and RHS substantially reduced lutein amounts in degummed soybean oil. Silica gel was the most effective adsorbent, followed by acid clay, and RHS. Treatments with adsorbents also reduced the residual free fatty acid (FFA) content. Aluminum oxide was the most effective in removal of FFA (approximately 40% reduction). RHS and rice hull ash (RHA) showed similar deacidification effects. RHS can be used as an alternative bleaching agent as it was effective in reducing the residual FFA content in soybean oil.     

Oil Bodies Extracted from High‐Fat and Low‐Fat Soybeans: Stability and Composition During Storage

Soybeans contain oil bodies (OBs) that encapsulate triacylglycerols (TAGs) with a phospholipid monolayer carrying scattered proteins. In nature, soybean OBs can form natural emulsions in aqueous media and may serve as natural, minimally processed, stable, and pre‐emulsified oil for addition into appropriate food systems. In this study, OBs were obtained by aqueous extraction from the mature seeds of 2 soybean crop cultivars, high‐fat soybean and low‐fat soybeans. The compositions of the extracted OBs were analyzed during storage at room temperature up to 14 d (pH = 7). The oxidative stability of these OBs, stored at 60 °C, was evaluated by measuring the presence of primary (lipid hydroperoxides) and secondary lipid oxidation products (malondialdehyde) by determining the standard peroxide value (PV) and thiobarbituric acid‐reactive substances (TBARS) value. During storage, the contents of unsaturated fatty acids, phospholipids, and tocopherols declined in both OBs, while their mean particle diameters (d₃₂) and ζ‐potentials increased. The changes in PV and TBARS values exhibited a similar trend for both OBs, but the OBs from low‐fat soybeans had significantly lower PV and higher TBARS values than the OBs from high‐fat soybean cultivars (P < 0.05). Overall, the OBs from both soybean cultivars had good stability during storage.     

滤油粉对大豆油煎炸品质的影响

目的考察滤油粉对大豆油煎炸品质的影响。方法以一级大豆油为研究对象,对其早期煎炸过程中的酸价、色泽、极性组分等3项评价指标进行检测并分析其变化趋势,并对煎炸后的食材进行了风味差异性对比的感官评价实验。结果随着煎炸时间的增加,使用了滤油粉后,一级大豆油的酸价、色泽、极性组分都呈现下降的趋势。此外,使用滤油粉的大豆油所炸制出来的的食物在风味上并没有明显差异。结论滤油粉能改善大豆油在煎炸过程中的部分品质。