桂花果实油脂脂肪酸组成的GC-MS分析

采用索氏提取法提取桂花果实核仁中的油脂,通过GC-MS分析油脂中脂肪酸的组成及含量。结果显示,桂花果实核仁油脂中鉴定9种脂肪酸,主要包含油酸(39.04%)、亚油酸(33.15%)、棕榈酸(10.31%)、硬脂酸(3.80%)、9,12-十八二烯酸(4.62%)和γ-亚麻酸(6.44%)。其中油酸和亚油酸等不饱和脂肪酸含量高达83.25%。桂花果实核仁中油脂的不饱和脂肪酸含量高,具有良好的应用前景。     

奇亚籽含油量及其脂肪酸组成分析

分析不同产地的奇亚籽油脂脂肪酸组成。采用索氏提取法提取奇亚籽中油脂,并对其甲脂化处理后用气相色谱法进行分析。结果表明,不同产地奇亚籽含油率相差较大,总体保持在25.5%～29.4%之间。样品间脂肪酸组分相同,共分离鉴定出17种脂肪酸,其中主要成分为不饱和脂肪酸,单不饱和脂肪酸油酸6.9%～7.8%,多不饱和脂肪酸亚油酸18.1%～19.7%,亚麻酸60.1%～62.9%。奇亚籽作为一种新食品原料,其油脂中亚麻酸的含量研究为奇亚籽的开发利用提供参考依据。     

湖南西部山核桃脂肪含量及脂肪酸组成研究

以湖南西部不同产地山核桃为试材,采用索氏提取法和GC-MS分析法,测定了8个不同产地(吉首、龙山、古丈、凤凰、麻阳、靖州、永定、慈利)山核桃仁中脂肪含量及其油脂中脂肪酸组成,并进行差异性和相关性分析。结果表明:山核桃仁中的脂肪含量在55.86%~61.57%,平均值为58.87%;山核桃油中共检测出棕榈酸、棕榈油酸、硬脂酸、油酸、亚油酸、α-亚麻酸、花生酸和二十碳烯酸8种脂肪酸,以油酸含量(67.01%)最高,其次为亚油酸23.9%、棕榈酸4.48%、硬脂酸2.42%、α-亚麻酸1.91%,其他脂肪酸含量较低,不饱和脂肪酸平均含量达到93.01%;主要脂肪酸含量差异程度依次为:油酸α-亚麻酸亚油酸棕榈酸硬脂酸,但含量差异不显著。     

混合脂肪酸的分离

以一般油脂加工副产物十八碳混合脂肪酸为原料,采用配合结晶梯度冷冻反萃取分离技术,不经任何热处理以避免聚合作用的发生,使混合脂肪酸中的饱和脂肪酸与不饱和脂肪酸分离,同时将不饱和脂肪酸分成油酸和(亚油酸+亚麻酸)两组分。后者含量可达95%以上。     

由菜籽油制备生物柴油的HPLC定量分析

采用反相液相色谱分离和紫外检测法定量分析了菜籽油制备生物柴油的主要组分分布及含量。结果表明,各脂肪酸甲酯、甘油单酯、甘油二酯及甘油三酯组分均能达到基线分离,且线性相关性良好,相关系数均在0.999 3以上,加标回收率在99.5%~103.7%之间,RSD在0.45%~2.38%(n)之间,该方法准确可靠。定量分析了菜籽油完全酯交换产品中油酸甲酯、亚油酸甲酯、亚麻酸甲酯组分含量分别为58.45%,20.02%,16.50%,三者之和为94.98%。菜籽油中三油酸甘油酯组分含量为38.76%。     

环氧油脂肪酸组成分析研究

通过薄层色谱、气相色谱、色质联用等技术,首次得到了油脂环氧化反应期间的脂肪酸环氧化反应规律:开始反应阶段,高含量不饱和脂肪酸反应速率高于低含量不饱和脂肪酸;环氧化反应期间,多不饱和脂肪酸首先生成单环氧酸,之后再逐渐生成二环氧酸,最后生成三环氧酸;富含亚麻酸的油脂环氧化反应时有更易于开环反应的趋向,其次是富含亚油酸的油脂,再次是富含油酸的油脂.实验结果表明,不同环氧油原料在进行环氧化反应时需要控制不同的反应条件,以避免开环副产物量的增加,从而制备得优质环氧油产品.     

选择加氢法改进豆油下脚料制油酸酰胺的稳定性

为改进豆油下脚料生产的润滑剂油酸酰胺碘值高、放置一段时间后迅速变黄等稳定性差的缺点．采用骨架镍催化剂选择性加氢油酸酰胺。使其中的亚油酸酰胺、亚麻酸酰胺等不饱和组分大部分转化力油酸酰胺而被除去，提高油酸酰胺的含量和使用性能。最佳反应条件为：反应温度160℃。反应压力0．4MPa，反应时间3．0h，催化剂用量3％。采用碘值结合放置后目测的方法进行了产品分析和评估。     

油酸酰胺的选择性加氢工艺研究

研究首次提出油酸酰胺直接选择性加氢工艺,选用价格低廉的骨架镍催化剂对油酸酰胺进行了选择性加氢,取得了较好的效果。实验结果表明,通过选择性加氢工艺,其中的亚油酸酰胺、亚麻酸酰胺等不饱和组分大部分转化为油酸酰胺而被除去,油酸酰胺含量由67.532%增加到76.198%,提高了油酸酰胺的含量和使用性能。得出反应条件为：反应温度160℃,反应压力405.3 kPa,反应时间3.0 h,催化剂加量3%。     

乙醇萃取结晶法分离硬脂酸和油酸的研究

硬脂酸和油酸是重要的化工原料,在橡胶、医药、塑料、制革等工业部门得到广泛应用。硬脂酸和油酸产品的主要原料为天然的动植物油脂。生产硬脂酸和油酸产品的工艺原理为油脂经水解操作得到混合脂肪酸(硬脂酸和油酸的混合物),然后对混合脂肪酸进行分离操作得到硬脂酸和油酸产品。分离硬脂酸和油酸的传统工艺是采用压榨法,     

食用氢化油脂肪酸的气相色谱分析

食用植物油中,不同程度的含有能使油脂氧化、水解、导致油脂酸败回味的亚麻酸和亚油酸,因而国内外食品工业用油一般使用食用氢化油。食用氢化油是把普通油脂在催化剂作用下进行选择性的轻度氢化,使油脂中亚麻酸等不饱和双键达到一定饱和程度,从而提高油脂的抗氧性和稳定性。     

Variation in Seed Oil Content and Fatty Acid Composition of Globe Artichoke Under Different Irrigation Regimes

Seed oil content of globe artichoke and its composition were assessed under three irrigation regimes, including irrigation at 20, 50, and 80 % depletion of soil available water. Water deficit affected the phenological characteristics, amount and the quality of the oil as well as the phenolics and antioxidant activity of the leaves and capitula. The seed oil content ranged from 18.7 % in 80 % to 22.8 % in 20 % treatment. The fatty acid composition of oil was determined using gas chromatography (GC). The predominant fatty acids in the oil were linoleic (51.68 %), oleic (34.22 %), palmitic (9.94 %), and stearic (3.58 %). Water deficit leads to reduced oil content, linoleic acid, the unsaturated/saturated fatty acid ratio and the iodine value. On the other hand, some other fatty acids such as palmitic and oleic acid and also the ratio of oleic/linoleic acid were elevated due to water deficit. Higher antioxidant activity was observed in capitula (IC₅₀ = 222.6 μg ml^?1) in comparison to the leaves (IC₅₀ = 285.8 μg ml^?1). Finally, the severe drought stress condition caused to gain higher oil stability, while the highest seed oil content and unsaturated fatty acids in the oil was obtained in non‐stress condition. Moreover, high phenolics, flavonoids and antioxidant activity as well as appreciable dry matter content were obtained in the moderate water stress condition.     

Variation in Fatty Acid Compositions, Oil Content and Oil Yield in a Germplasm Collection of Sesame (Sesamum indicum L.)

The variation in oil content, oil yield and fatty acid compositions of 103 sesame landraces was investigated. The landraces varied widely in their oil quantity and quality. The oil content varied between 41.3 and 62.7%, the average being 53.3%. The percentage content of linoleic, oleic, palmitic and stearic acids in the seed oil ranged between 40.7–49.3, 29.3–41.4, 8.0–10.3 and 2.1–4.8%, respectively. Linolenic and arachidic acids were the minor constituents of the sesame oil. Linoleic and oleic acids were the major fatty acids of sesame with average values of 45.7 and 37.2%, respectively. The total means of oleic and linoleic acids as unsaturated fatty acids of sesame were about 83% which increases the suitability of the sesame oil for human consumption. The superiority of the collection was observed in oil content. The oil content of a few accessions was above 60%, proving claims that some varieties of sesame can reach up to 63% in oil content. The accessions with the highest oil content were relatively richer in the linoleic acid content while there were some landraces in which linoleic and oleic acid contents were in a proportion of almost 1:1. The results obtained in this study provide useful background information for developing new cultivars with a high oil content and different fatty acid compositions. Several accessions could be used as parental lines in breeding programmes aiming to increase sesame oil quantity and quality.     

Influence of Temperature on the Fatty Acid Composition of the Oil From Sunflower Genotypes Grown in Tropical Regions

The influence of temperature on the fatty acid composition of the oils from conventional and high oleic sunflower genotypes grown in tropical regions was evaluated under various environmental conditions in Brazil (from 0° S to 23° S). The amounts of the oleic, linoleic, palmitic and stearic fatty acids from the sunflower oil were determined using gas chromatography (GC). The environment exhibited little influence on the amounts of oleic and linoleic fatty acids in high oleic genotypes of sunflower. In conventional genotypes, there was broad variation in the average amounts of these two fatty acids, mainly as a function of the minimum temperature. Depending on the temperature, especially during the maturation of the seeds, the amount of oleic acid in the oil of conventional sunflower genotypes could exceed 70 %. Higher temperatures led to average increases of up to 35 % for this fatty acid. Although the minimum temperature had the strongest effect on the fatty acid composition, locations at the same latitude with different minimum temperatures displayed similar values for both oleic acid and linoleic acid. Furthermore, minimum temperature had little influence on the amounts of palmitic and stearic fatty acids in the oil.     

Current advances in sunflower oil and its applications

The fatty acid and triacylglycerol composition of a vegetable oil determine its physical, chemical and nutritional properties. The applications of a specific oil depend mainly on its fatty acid composition and the way in which fatty acids are arranged in the glycerol backbone. Minor components, e. g. tocopherols, also modify oil properties such as thermo‐oxidative resistance. Sunflower seed commodity oils predominantly contain linoleic and oleic fatty acids with lower content of palmitic and stearic acids. High‐oleic sunflower oil, which can be considered as a commodity oil, has oleic acid up to around 90%. Additionally, new sunflower varieties with different fatty acids and tocopherols compositions have been selected. Due to these modifications sunflower oils possess new properties and are better adapted for direct home consumption, for the food industry, and for non‐food applications such as biolubricants and biodiesel production.     

Some chemical processes utilizing oleic safflower oil

Oleic safflower seed (UC-1) produces an oil containing approximately 80% oleic acid and 12% linoleic acid. The oil is a source of high quality oleic acid, and fatty acids from the oil may be used without further separation in some applications where technical oleic acid is now used, since oleic safflower free fatty acids have a a higher oleic acid content than good commercial grades of oleic acid. A high purity oleic acid can be produced by urea fractionation. Ozonization of the oil followed by reductive cleavage yields pelargonaldehyde and nearly colorless aldehyde oils. Ozonization of a crude mixture of oleic safflower acids followed by oxidative cleavage provides high yields of azelaic acid and pelargonic acid. In contrast, ozonization of free fatty acids from polyunsaturated vegetable oils produces azelaic acid and mixtures of lower molecular weight carboxylic acids with smaller amounts of pelargonic acid. Furtherore, ozone consumption is lower and reaction time is shorter when oleic safflower acids are used in place of more highly unsaturated fatty acids.     

Chemical Composition and Fatty Acid Profile of Khat (Catha edulis) Seed Oil

The proximate, physicochemical, and fatty acid compositions of seed oil extracted from khat (Catha edulis) were determined. The oil, moisture, crude protein, crude fiber, crude carbohydrate, and ash content in seeds were 35.54, 6.63, 24, 1.01, 30.4 %, and 1.32 g/100 g DW respectively. The free fatty acids, peroxide value, saponification value, and iodine value were 2.98 %, 12.65 meq O₂/kg, 190.60 mg KOH/g, and 145 g/100 g oil, respectively. Linolenic acid (C_18:3, 50.80 %) and oleic (C_18:1, 16.96 %) along with palmitic acid (C_16:0, 14.60 %) were the dominant fatty acids. The seed oil of khat can be used in industry for the preparation of liquid soaps and shampoos. Furthermore, high levels of unsaturated fatty acids make it an important source of nutrition especially as an animal product substitute for omega‐3 fatty acids owing to the high content of linolenic acid.     

Comparison of Fatty Acid Profile of Specialty Maize to Normal Maize

Increasing utilization of specialty maize prompted us to evaluate its fatty acid profile. For this purpose maize germplasm, classified as low oil normal maize (group 1), high oil normal maize (group 2), quality protein maize (QPM) (group 3) and sweet corn (group 4) was evaluated for oil, starch, protein and fatty acid composition mainly palmitic, stearic, oleic and linoleic acid. High oil content was observed in sweet corn samples which might be result of shriveled grain texture because of an increased embryo to kernel ratio. Individual fatty acids showed wide differences among different groups. A slightly higher amount of palmitic acid was reported in specialty maize as compared to normal maize. In contrast, stearic acid content was significantly low in high oil normal maize (56 %), QPM (36.2 %) and sweet corn (28.4 %) in comparison to low oil normal maize. Although no significant differences were observed for oleic acid between low oil normal and high oil normal maize, but sweet corn samples showed significantly reduced oleic acid compared to low oil normal maize. However, the most important observation was the higher content of linoleic acid in specialty maize (groups 2, 3 and 4) as compared to low oil normal maize. Further, the ratio of MUFA/PUFA was also discussed. It was concluded that specialty maize possesses a better oil quality in comparison to low oil normal maize.     

Chemical Properties and Fatty Acid Composition of Thunbergia fragrans Roxb. Seed Oil

The physicochemical and fatty acid compositions of seed oil extracted from Thunbergia fragrans were determined. The oil content, free fatty acids, peroxide value, saponification value and iodine value were 21.70 %, 2.25 % (as oleic acid), 9.6 (mequiv. O₂/kg), 191.71 (mg KOH/g) and 127.84 (g/100 g oil) respectively. The fatty acid profiles of the methyl esters showed the presence of 90.16 % unsaturated fatty acids and 9.84 % saturated fatty acids. Palmitoleic acid, which is usually found in marine foods and is unique in seed oils of botanical origin, was the major component (79.24 %). The oil can also be used in industries for the preparation of liquid soaps, shampoos and alkyd resin.     

The Interaction of the Soybean Seed High Oleic Acid Oil Trait With Other Fatty Acid Modifications

Oil value is determined by the functional qualities imparted from the fatty acid profile. Soybean oil historically had excellent use in foods and industry; the need to increase the stability of the oil without negative health consequences has led to a decline in soybean oil use. One solution to make the oil stable is to have high oleic acid (>70%) and lower linolenic acid content in the oil. Other fatty acid profile changes are intended to target market needs: low‐saturated fatty acid and high stearic acid content in the oil. The objective of this study is to determine the interaction of the high oleic acid oil trait with other alleles controlling fatty acid profiles. Soybean lines containing high oleic acid allele combinations plus other fatty acid modifying alleles were produced, and the seed was produced in multiple field environments over 2 years. Stable high oleic acid with low linolenic acid (<3.0%) was achieved with a 4‐allele combination. The target of >20% stearic acid in the seed oil was not achieved. Reducing total saturated fatty acids below 7% in a high oleic acid background was possible with mutant alleles of both an acyl‐ACP thioesterase B and a β‐ketoacyl‐[acyl‐carrier‐protein] synthase III gene. The results identified allele combinations that met the target fatty acid profile thresholds and were most stable across environments.