油脂加工副产物—脱臭馏出物的综合利用

油脂脱臭馏出物是植物油精炼脱臭时的副产物,含有多种活性成分,提取、纯化和应用这些活性成分已成为研究的热点。为了促进脱臭馏出物的综合开发利用,本文综述植物油脱臭馏出物中天然VE、植物甾醇、角鲨烯、脂肪酸甲酯等多种活性成分的理化性质、提取纯化方法及应用延伸。结果表明,植物油脱臭馏出物是天然VE的较好来源,且不同来源的脱臭馏出物中提取的天然VE的组成有所不同。从脱臭馏出物中提取VE多采用酯化法、尿素络合法、酶法、溶剂萃取法、分子蒸馏法、离子交换法、吸附法、柱层析法、超临界萃取法等两种或多种方法的组合形式进行富集和纯化。目前市场上的天然VE的品种大致分为四类:混合生育酚、天然α-生育酚、天然α-生育酚衍生物、混合生育酚/天然α-生育酚粉末等。从脱臭馏出物中提取植物甾醇通常分两步,先从原料中提取粗甾醇,然后采用溶剂结晶、络合法、吸附法、酶法等精制方法精制甾醇。植物甾醇的应用延伸包括水溶性植物甾醇、谷甾醇、豆甾醇、4AD、ADD和多种甾体皮质激素药物。从脱臭馏出物中提取角鲨烯通常是先提取不皂化物,然后从不皂化物中采用超临界CO2萃取、色谱分离、分子蒸馏法、吸附分离法等进一步提取角鲨烯。脱臭馏出物中脂肪酸的含量一般在25%~75%之间,这些脂肪酸在制备天然VE和植物甾醇的过程中转化为脂肪酸甲酯,而以脂肪酸甲酯为原料可制备生物柴油、单双甘油酯、环氧脂肪酸甲酯、表面活性剂和洗涤剂等产品,使得油脂脱臭馏出物得到进一步的综合利用。     

米糠油及其脱臭馏出物中生育酚和生育三烯酚的分析检测

对米糠油及其脱臭馏出物中生育酚及生育三烯酚含量进行检测分析,结果表明,米糠来源和米糠油精炼工艺对米糠油及其脱臭馏出物中α、β、γ、δ-生育酚和生育三烯酚的含量有显著影响。米糠毛油中生育三烯酚占维生素E总量的60%～70%,脱臭馏出物中生育三烯酚占维生素E总量的25%～40%,米糠油脱臭馏出物维生素E总量中生育三烯酚的含量较米糠毛油有较大的损失。通过对米糠油脱臭馏出物不皂化物的分析检测可知,米糠油脱臭馏出物中主要甾醇的种类为豆甾醇、菜油甾醇、谷甾醇,总甾醇含量很少,仅为0.32%;除此之外,还有少量日耳曼甾醇、羊毛甾醇、3,5-二烯豆甾烷等。     

大豆油脱臭馏出物中同时提取角鲨烯、生育酚和植物甾醇的工艺研究

采用酯化—高真空蒸馏工艺路线,从大豆油脱臭馏出物中同时提取角鲨烯、生育酚及植物甾醇。考察酯化条件(甲醇、催化剂浓硫酸用量及反应时间)对酯化率、角鲨烯和生育酚含量的影响。优化得到的最佳工艺为:催化剂浓硫酸添加量0.5%,醇油摩尔比10∶1,反应温度70℃,反应时间120 min,大豆油脱臭馏出物酯化率达到98.2%,生育酚和角鲨烯保留率分别为97.7%和97.5%。酯化后的物料通过冷析结晶,抽滤得到植物甾醇粗品,滤液高真空蒸馏,初步分离得到脂肪酸甲酯、角鲨烯、生育酚等组分。各组分中角鲨烯富集到12.2%,生育酚富集到28.6%,植物甾醇富集到60%左右,初步实现了大豆油脱臭馏出物中角鲨烯、生育酚、植物甾醇的同时提取,为角鲨烯、生育酚及植物甾醇的进一步富集提供了参考依据。     

植物油脱臭馏出物生物活性成分提取与纯化技术研究进展

油脂脱臭馏出物是植物油精炼脱臭时副产品,含有生育酚、甾醇、角鲨烯等生物活性成分,提取和纯化这些活性成分已成为研究热点;该文综述植物油脱臭馏出物生物活性成分提取与纯化技术研究进展。     

油脂脱臭馏出物的回收和利用

在油脂脱臭过程中，可以得到油脂总量约０．３％左右的馏出物，其中含有有ＶＥ效果的生育酚及甾醇等。以有效的回收工艺，将脱臭馏出物作为浓缩生育酚的原料，采用甲醇酯化和分子蒸馏组合的工艺和设备，可以制取纯度７０％以上的生育酚浓缩物，回收率在５０％—６０％。     

真空蒸馏-萃取法提纯天然生育酚的工艺

以甲酯化的大豆油脱臭馏出物为原料,从中分离提纯天然生育酚.首先将甲酯化后的大豆油脱臭馏出物进行冷冻结晶,通过离心分离甾醇;然后再采用真空蒸馏和乙醇萃取工艺提纯生育酚.研究了提纯的工艺条件及工艺过程中生育酚含量的变化.实验结果表明,经过提纯后生育酚含量为55.7%,生育酚总收率约为89.0%.     

硫酸对大豆油脱臭馏出物中天然VE和植物甾醇的影响

作为脂肪酸酯化催化剂,浓硫酸与固体酸和酯化酶相比,具有成本低,效率高,操作简单等特点。因此,浓硫酸在大豆油脱臭馏出物提取天然VE生产过程中广泛用于脂肪酸的酯化工艺。本研究考察了以浓硫酸作为天然维生素E酯化工艺的催化剂,在反应和后处理过程中硫酸对VE和植物甾醇收率的影响,并取得了一些非常有意义的发现。大豆油脱臭馏出物中天然VE包括α、β、γ、δ-生育酚,植物甾醇主要包含谷甾醇、豆甾醇、菜油甾醇和菜籽甾醇。实验结果显示,硫酸浓度和温度对大豆油脱臭馏出物中天然VE和植物甾醇的影响显著。硫酸浓度和温度越高对天然VE和植物甾醇破坏越快。同时发现天然VE中α-生育酚的耐酸性显著好于其他三种生育酚。在生产过程中为了减小硫酸对天然VE和植物甾醇的破坏,应合理控制硫酸使用条件。     

优化油脂脱臭馏出物生产的研究

油脂脱臭馏出物是生产天然生育酚的好原料。油脂脱臭馏出物的价值主要取决于其生育酚的含量。油脂种类、油脂精炼工艺条件、馏出物的储存条件等,都会影响脱臭馏出物的得率及其组成。研究以上条件对脱臭馏出物得率及生育酚的含量的影响,进而优化油脂脱臭馏出物的生产,对提高油脂脱臭馏出物的经济价值是十分重要的。     

以生育酚为目标的油脂脱臭馏出物的生产

近年来 ,富含生育酚的脱臭馏出物具有很高的应用价值。脱臭馏出物中生育酚的含量与油脂精炼工艺、脱臭时间、脱臭温度、捕集器温度、蒸汽用量和系统真空度等因素有关。提出一些建议以提高脱臭馏出物中生育酚的含量 ,但不影响精炼油的质量。     

分子蒸馏法浓缩α-生育酚的工艺研究

采用三级分子蒸馏,从大豆油脱臭馏出物中浓缩α-生育酚.一、二级分子蒸馏通过单因素试验确定优选工艺;三级分子蒸馏采用响应曲面法对操作条件进行优化.试验结果表明,将大豆油脱臭馏出物进行甲酯化预处理后,再通过3次分子蒸馏,并结合两次脱除甾醇,可明显提高生育酚质量分数,α-生育酚质量分数从0.48％提高至3.59％.     

自然条件及加工条件对大豆维生素E含量的影响

随着人们对维生素E消费量的增长，从植物油料中获得更多维生素E的研究势在必行。影响大豆维生素E含量和质量的因素很多，不同的自然条件下(不同种植地域、不同基因组成、不同生长条件、不同的储藏条件等)，大豆维生素E含量不同。此外，不同加工工艺，如大豆预处理、毛油脱胶、脱酸、脱色、脱臭对大豆油中生育酚的含量的变化也具有不同程度的影响。     

Separating Tocotrienols from Palm Oil by Molecular Distillation

Crude palm oil contains approximately 1% minor components, including carotenoids and vitamin E (tocopherols and tocotrienols), which contribute to the stability and nutritional properties of palm oil. Palm oil is considered one of the best sources of vitamin E. The vitamin E content in palm oil is unique because it is composed of tocotrienols rather than tocopherols. Palm fatty acid distillate (PFAD) is the volatile organic material recovered as a valuable by-product in the deodorization of palm oil. Several processes have been proposed for recovering tocopherols and tocotrienols from PFAD. For this separation process, it is necessary to develop a processing procedure to extract the valuable tocotrienols and other minor components from PFAD using molecular distillation. Molecular distillation occurs at low temperatures and reduces the problem of thermal decomposition. High vacuum also eliminates oxidation that might occur in the presence of air. The rate of evaporation is controlled by the rate at which the molecules escape from the free surface of the liquid and condense on the condenser. The effects of feed-flow rate and temperature of distillation on extraction of minor components from PFAD are based on concentrations, distribution coefficients, and relative volatilities. The separation of tocotrienols from PFAD approached maximum values at low temperatures and fell drastically as temperature increased. For the optimum conditions for the extraction of tocotrienols with high yield and purity, it is necessary to determine the effect of processing variables on the extraction of minor components (i.e., tocotrienols, α-tocopherol) from the PFAD in terms of concentrations in the liquid and vapor phases, to reveal the behavior of target components in the evaporation process, and to determine the evaporation and volatility properties of tocotrienols and other minor components from PFAD.     

油脂在脱臭后反式脂肪酸的生成及维生素E的损失问题的探讨

叙述了在油脂脱臭过程中油中顺式脂肪酸 转化成反式脂肪酸以及油中维生素Ｅ的损失问题。另外,还提出了用用新式填料式脱臭塔替代目前常用的盘式脱臭塔问题,因为前者的水蒸汽耗用量少,反式脂肪酸生产量也少,并生育保留量却较多,其优越性是很明显的。     

Tocopherol composition of deodorization distillates and their antioxidative activity

During the last stage of plant oil refining, deodorization distillates containing very important biological substances such as tocopherols, sterols, terpenoids or hydrocarbons are formed as a by-products. This study aimed at evaluating the content and antioxidant capacity of tocopherol concentrates from deodorization distillates obtained after the refining of rapeseed, soybean and sunflower oil. The majority of the matrix substances were eliminated from deodorization distillates by freezing with an acetone solution at -70 degrees C. The tocopherol concentrates obtained in this way contained approximately fivefold more tocopherols than the quantity in condensates after deodorization. Antioxidant activity was investigated by observing the peroxide value at 25 degrees C and using the Oxidograph test. The test medium was lard enriched with the tocopherol concentrates of the three plant oils versus single, synthetic alpha-, gamma- and delta-tocopherols (-T), which served for comparison. In these model systems, all investigated tocopherol concentrates exhibited antioxidant capacity. Their antioxidant effect was significantly lower than that of single delta-T and gamma-T, but significantly higher than alpha-T. The results prove that natural tocopherol concentrates obtained from plant oils are valuable food antioxidants and they also increase the biological and nutritional value of food especially when administered to animal fats or food of animal origin. Tocopherol concentrates can fully replace synthetic antioxidants that have been used thus far.     

Optimisation of enzymatic pretreatment of soybean oil deodoriser distillate for concentration of tocopherols

Tocopherols have been purified from the deodoriser distillate produced in the final deodorisation step of vegetable oil refining by a process including molecular distillation. The deodoriser distillate contains mainly tocopherols, sterols and free fatty acids (FFAs); the presence of FFAs hinders tocopherol purification. In general, Candida rugosa lipase recognised FFAs as substrates but not tocopherols, and esterification of FFAs with methanol (MeOH) could be processed in an organic solvent-free system. Several factors affecting esterification of FFAs were investigated in detail and optimised by the Plackett–Burman and the central composite design. The optimal reaction conditions are as follows: water content 21.05%, lipase 115.45 U g⁻¹ mixture, temperature 28.95 °C and addition of methanol and FFA in a molar ratio of 4:1 in four steps, with degree of decrease of acid value (AV) above 93% in 18 h; this was a much efficient process. No significant tocopherol losses were observed during the process. In conclusion, enzymatic esterification of FFAs in soybean oil deodoriser distillate for concentration of tocopherols was shown to be a technically viable process.     

Refining of high oleic safflower oil: Effect on the sterols and tocopherols content

The purpose of this work was to study the influence of the industrial process steps on free fatty acids, peroxide value (PV), p-anisidine value (PAV), trans fatty acids, tocopherols and sterols (free, esterified and total) in high oleic safflower oil. Degumming, bleaching and deodorization steps removed 91.4% of free fatty acids, 96.31% of oxidation primary products (PV), and 54.57% of oxidation secondary products (PAV), from crude high oleic safflower oil. Degumming neither affected the content of sterified sterols nor its proportion with respect to the crude oil. A significant increment (p<0.05) in the content of free sterols was observed during degumming and bleaching due to the acid-catalyzed hydrolysis of steryl esters. A significant reduction (p<0.05) in the content of total sterols during bleaching was observed, which is attributed to a reduction in the sterified sterol fraction. During deodorization, free sterols were distilled from oil, with a gradual reduction in the total sterol content as a function of the deodorization temperature. α- and γ-tocopherols represented 93.3% of the total tocopherols in high oleic safflower crude oil. The refining process removed 28.5% of the tocopherols. Deodorization was the main step which increased the level of trans fatty acids as an effect of temperature and heating time.     

Concentration of tocopherols by supercritical carbon dioxide with cosolvents

In order to optimize the conditions for enrichment of tocopherols, tocopherol extraction from chemically modified rapeseed deodorizer distillate (RDD) at three levels (2%, 4%, and 6%) of each cosolvent (methanol, ethanol, and mixed ethanol) was carried out by using supercritical carbon dioxide (SC-CO₂). After chemical modification, the fatty acid methyl esters (FAME) in RDD were produced and showed improved solubility in SC-CO₂. Since FAME were more volatile, they were extracted preferentially over tocopherols and other higher molecular weight compounds. Two steps were applied in the SC-CO₂ extraction. First, the FAME mixture was extracted under 120 bar until the weight of extracts did not increase anymore, and then, tocopherols were concentrated under 250 bar. Second, the concentrates from the first step under 250 bar were esterified and then extracted again under 120 bar until the weight of extracts did not increase anymore. Different cosolvents (methanol, ethanol, mixed ethanol) were used for tocopherol isolation under 250 bar in the second step. Tocopherol content, tocopherol recovery and the weight of target extract (those extracts with a concentration of tocopherols above 40%) increased while the extraction time decreased.     

脱臭工艺对葵花籽油品质的影响

研究脱臭工艺对葵花籽油品质的影响,分析在不同脱臭温度、脱臭时间条件下,葵花籽油酸值、过氧化值、生育酚、角鲨烯、甾醇和反式脂肪酸的变化情况。结果表明:随脱臭温度升高,脱臭时间的延长,酸值、过氧化值逐渐降低,生育酚、甾醇、角鲨烯含量显著减少,反式脂肪酸含量增加。通过研究葵花籽油在不同脱臭工艺条件下的品质变化情况,以期为葵花籽油实际脱臭工艺提供数据支持。