The extent of hydrogenation of two formaldehyde-treated spray-dried mixtures of soya bean oil and casein fed to sheep

Two experiments have been carried out to determine the degree of protection of soya bean oil mixed with sodium caseinate, spray-dried and treated with formaldehyde. In experiment 1, the mixture contained two parts of oil to one part of sodium caseinate. In experiment 2, the mixture contained six parts of oil to one part of sodium caseinate. The animals also received either no added oil, or the same amount of free oil and, in experiment 2, the powder without any formaldehyde treatment. The basal diet used consisted of equal amounts of dried grass cubes and flaked maize. There were no statistically significant effects on the apparent digestibility of the dry matter, organic matter, nitrogen or total fatty acid. The amount of polyunsaturated fatty acids (18:2 and 18:3) voided in the faeces was not affected by the form of oil. The amount of 18:0 and 18:1 in the faeces was increased by all the different forms of oil. The proportion of polyunsaturated fatty acids in both the solid and the liquid parts of the rumen digesta was markedly increased when the protected powder was added to the diet. This effect was most marked in the liquid. The amount of polyunsaturated fatty acids flowing to the duodenum was markedly increased when the protected powder was given. Of the 18:2 and 18:3 fatty acids added to the food in the soya bean oil, less than 6% passed to the duodenum when either loose oil or unprotected powder was added whereas, when the protected powder was added in experiment 1, 66% of the added polyunsaturated fatty acid passed to the duodenum and the corresponding figure in experiment 2 was 40%. It is concluded that the method of protection used was reasonably effective but that the amount of casein in the second preparation was not sufficient to afford optimum protection.     

四棱豆油脂、脂肪酸、蛋白质、氨基酸的分析

以4 个四棱豆品种的种子为材料,采用索式提取法、毛细管柱测定总脂肪含量及分析各脂肪酸含量;利用凯氏定氮法、全自动氨基酸分析仪测定蛋白质总量及各蛋白氨基酸组成。结果表明,四棱豆种子中油脂总量在20%～22%,主要含有28 种脂肪酸,油酸占单不饱和脂肪酸的90.7%;多不饱和脂肪酸主要为亚油酸、α - 亚麻酸和EPA;饱和脂肪酸平均含量为25.76%,主要为棕榈酸和硬脂酸。蛋白质总量在38% 左右,必需氨基酸含量丰富。     

Effect of fat-enriched diets on rabbit meat fatty acid composition

The effects of beef tallow-, soya and sunflower olein- and soya bean oil-enriched (3%) diets on the chemical and fatty acid composition of total, a polar and polar lipids of rabbit meat have been studied. No significant differences (P > 0.05) in the meat chemical composition were observed between groups. However, a large effect of the diet on the total and apolar lipid fatty acids was found, with C18:1 and C18:2 the most affected fatty acids. The influence of the diets on the fatty acids of the polar fraction was less marked. It is concluded that the enrichment of the rabbit diet with either soya and sunflower oleins or soya bean oil allows the production of rabbit meat with a higher unsaturation degree than is obtained by using conventional diets, which constitutes an important nutritional benefit to the human being.     

Quality assessment of refined oil blends during repeated deep frying monitored by SPME–GC–EIMS,GC and chemometrics

The aim of this study was to investigate the effect of the refined palm oil addition (20%) on the fatty acid and sterol compositions of refined olive oil or refined soya bean oil and also to investigate the formation of total polar compounds and volatile compounds in these oil blends during fifty successive deep‐frying sessions of potato fries at 180 °C. The blend of refined olive oil and refined palm oil exhibited a higher chemical stability during the frying process than that of refined soya bean oil and refined palm oil. Indeed, the total polar compounds and volatile compounds formed, especially 2,4‐decadienal, were found to be relatively increased in the refined soya bean oil/refined palm oil blend reaching 36.50% and 46.70%, respectively, after fifty deep‐frying sessions. Moreover, the degradation of linoleic acid and β‐sitosterol was significantly (P < 0.05) observed for the refined soya bean oil/refined palm oil blend. The results have proven that the proper blending of monounsaturated refined olive oil with refined palm oil increases its stability and hence improves the quality of such olive oil during frying process.     

Changes in Soya Bean Lipid Profiles during Kinema Production

The influence of processing on soya bean lipids during kinema production was studied. The crude lipid (CL), free fatty acid (FFA) and phytosterol contents of raw beans were 121 g, 6·9 g and 0·8 g kg⁻¹ dry matter, respectively. After soaking and cooking the moisture content of beans increased significantly from 121 to 749 g kg⁻¹, whilst the lipid contents were unchanged. During a 2 day fermentation at 37°C, the lipid contents increased significantly as indicated by capillary column gas chromatography (GC) analysis of petroleum ether extracts of lyophilised samples of unfermented and fermented beans. The fatty acids, palmitic (C16:0), stearic (C18:0), oleic (C18:1), linoleic (C18:2), linolenic (C18:3) and arachidic (C20:0) acids were identified. The major fatty acid present in all samples was the essential fatty acid, linoleic acid. All of the aforementioned fatty acids (except arachidic) were liberated during fermentation by microbial lipases, yielding approximately the same proportion of fatty acids found in unfermented beans. The unsaponifiable soya bean lipids identified by GC were campesterol, stigmasterol and β-sitosterol (ratio 1·2:1:3·4). Levels of these increased during fermentation by 50–61%, but remained in approximately the same proportions.     

不同甲酯化方法对裂壶藻产油脂肪酸的影响及GCMS分析

为了研究不同的甲酯化方法对裂壶藻产油脂肪酸的影响,本文通过对裂壶藻进行发酵培养得到纯藻体,再经过酶法破壁、冷冻干燥得到干藻体后采用索氏提取法提取油脂。运用酸法、碱法和三氟化硼法三种甲酯化方法对藻油进行处理,基于气相色谱-质谱联用(GC-MS)技术分析了藻油中DHA(二十二碳六烯酸)等脂肪酸的组成和含量。结果表明:酸法、碱法、三氟化硼法分别鉴定出11种、19种和12种脂肪酸,占裂壶藻藻油总量的89.50%、97.88%和90.12%。其中酸法酯化的藻油中DHA占脂肪酸总量的38.89%;碱法酯化的藻油中DHA占脂肪酸总量的46.76%;三氟化硼法酯化的藻油中DHA占脂肪酸总量的40.54%。所以,碱法相较于酸法和三氟化硼法有明显的优势,更适合用于裂壶藻藻油的脂肪酸分析。进一步对碱法的甲酯化温度进行梯度实验,结果表明温度为55℃时,DHA的相对含量为47.45%,藻油的甲酯化效果最好。这一研究对长链多不饱和脂肪酸的检测鉴定有着重要的意义。     

Supercritical CO2 extraction of oil from Arctic charr side streams from filleting processing

Although Arctic charr side streams contain limited amounts of fish flesh, they are a rich fish oil source (46.3 ± 0.6%). The aim of the study was to investigate the potential for valorization of Arctic charr filleting side streams through the extraction of oil by supercritical CO₂ technology. The effect of temperature (40 °C and 80 °C) and pressure (20, 35 and 45 MPa) on the final extract after supercritical fluid extraction (SFE) was evaluated. Temperature increase enhanced the yield but decreased the antioxidant activity at 45 MPa, did not affect the yield and the antioxidant activity at 35 MPa, whereas yield was limited at 20 MPa and 80 °C. Extracts were rich in monounsaturated fatty acids (56.7–58.3%, especially oleic acid 37.2–38.0%), and polyunsaturated fatty acids (20.2–26.1%, especially DHA 7.3–11.4%). The presence of astaxanthin significantly preserved the extracts from oxidation.Industrial relevanceSupercritical carbon dioxide extraction is a green technology appropriate for the recovery of non-polar and heat sensitive compounds. The extracted Arctic charr oils were rich in polyunsaturated fatty acids and astaxanthin which inhibited oxidation in combination with the absence of oxygen and light during the process. This technology could be an excellent alternative for more sustainable valorization of fish processing side streams.     

Effects of Oxygen Absorber and Temperature on ω3 Polyunsaturated Fatty Acids of Sardine Oil during Storage

To prevent loss of w3 polyunsaturated fatty acids over long-term preservation, the effects of temperature and oxygen absorber on the fatty acids of sardine oil stored in air-tight film were studied. The fatty acids of sardine oil and lipids in the diet of experimental animals rapidly decreased over 1 month at 22°C. The amounts in the diet decreased slowly at 2°C; however, no alterations in the oil samples were observed for 6 months. Also, the amounts did not change at -30°C. Significant changes in samples treated with oxygen absorber were not observed under all temperatures during 6 months storage (P > 0.05). These results indicate that treatment with an oxygen absorber and/or freezing can prevent ω3 polyunsaturated fatty acids of fish oil from decreasing during storage.     

Optimisation of enzymatic esterification of soybean oil deodoriser distillate

The enzymatic esterification of free fatty acids from soybean oil deodoriser distillate with ethanol, catalysed by immobilised fungal lipase, was studied. The extent of conversion of free fatty acids to ethyl esters was optimised using a response surface methodology obtained through a second‐order factorial experimental design. The variables studied were reaction temperature (30–70 °C), enzyme concentration (7–23%) and ethanol/free fatty acid molar ratio (0.3–3.7:1). The optimal reaction conditions achieved were temperature from 46.4 to 53.6 °C, enzyme concentration from 13.6 to 16.5% and ethanol/free fatty acid molar ratio from 1.7 to 2.3:1, with conversions above 88%. No significant tocopherol losses were observed during the process. In conclusion, enzymatic fatty acid esterification was shown to be a technically viable process. © 2001 Society of Chemical Industry     

Application of response surface methodology to optimise supercritical carbon dioxide extraction of oil from rapeseed (Brassica napus L.)

Supercritical CO₂ fluid extraction technology was used to extract oil from rapeseed. Extraction temperature, pressure, time and the sample particle size were selected and optimised by response surface methodology. Conventional solvent extraction was applied as a comparative method. The maximum extraction yield of 32.65 ± 1.01% was achieved at a temperature of 40 °C and a pressure of 345 bar, using an extraction time of 3 h and a 60‐mesh particle size. The chemical compositions of rapeseed oil using esterification method were investigated by GC–MS. The result indicates that the main fatty acids are palmitic acid (2.60%), oleic acid (16.54%), linoleic acid (9.62%), linolenic acid (4.77%), eicosenoic acid (11.20%) and erucic acid (47.09%), respectively. Supercritical fluid extraction has been proved to be an effective technique for extracting oil from Brassica napus L.     

豆类脂肪酸分析方法研究现状及进展

文章就豆类食品(以大豆制品为主)油脂抽提和脂肪酸甲酯化方法进行综述,并阐述脂肪酸的多种生理功能,分析各种不同脂肪酸检测方法差异,以期为豆制品加工过程中脂肪酸变化规律研究提供测试方法,为可能的功能性油脂食品开发提供依据。     

两种不同酯化方法分析荞麦中脂肪酸成分

采用索氏提取法对荞麦油进行了提取,分别采用两种方法进行甲酯化处理,以气相色谱-质谱联用仪进行了分析,对脂肪酸组成和含量进行了比较。结果表明:两种酯化方法分别鉴定出8种脂肪酸,占荞麦油总量的98.64%和99.97%;方法1鉴定出的主要脂肪酸为:棕榈酸占脂肪酸总量的15.92%,亚油酸占脂肪酸总量的30.37%,油酸占脂肪酸总量的35.32%;方法2鉴定出的棕榈酸占脂肪酸总量的35.66%,亚油酸占脂肪酸总量的11.75%,油酸占脂肪酸总量的33.26%。     

酶法全酯化合成富含EPA/DHA甘油酯工艺研究

以富含EPA/DHA的脂肪酸为底物,采用两步酶法合成富含EPA和DHA的甘油酯。首先,以T1脂肪酶为催化剂催化富含EPA/DHA的脂肪酸和甘油反应;在最优条件为:反应温度40℃,水分添加量为底物混合物的3%、甘油与脂肪酸摩尔比3∶1和酶添加量50 U/g底物混合物时,富含EPA/DHA的脂肪酸的转化率达到62%以上,此时产物中甘油三酯、甘油二酯、甘油单酯的质量分数分别为10.52%、38.15%、25.64%。将游离酶催化酯化反应产物中的油相回收,利用自制的固定化CALB(LipozymeCALB L固定于环氧树脂ECR8285上)为催化剂,在真空条件下继续催化未反应的脂肪酸与偏甘油酯(甘油单酯和甘油二酯)继续酯化反应12 h,此时产物中甘油三酯、甘油二酯和甘油单酯的质量分数分别达到38.34%、51.02%、10.63%,没有检测到脂肪酸的存在。     

马兰籽油中脂肪酸的不同甲酯化方法与GC-MS 分析

采用索氏提取法对马兰籽中马兰籽油进行提取,分别采用两种方法进行甲酯化处理,以气相色谱- 质谱联用仪进行分析,对它们的脂肪酸组成和相对含量进行比较。结果表明：酯化方法l 和酯化方法2 分别鉴定出16 种和6 种脂肪酸,占马兰籽油总量的98.66% 和63.68%,两种方法酯化的马兰籽油中鉴定出主要脂肪酸均为十八碳二烯酸、十八碳烯酸、十六酸。     

Optimising drying parameters to maximise omega‐3 essential fatty acid yields in striped weakfish (Cynoscion striatus) industry waste

Fish processing produces high amounts of wastes with low commercial value. Nevertheless, this material could be valorised through the extraction of its polyunsaturated fatty acids. Therefore, the purpose of this study was to evaluate the drying process of striped weakfish (Cynoscion striatus) waste in an air‐circulating oven, aiming to preserve the omega‐3 content. The microbiological and chemical characteristics of the dried product were evaluated. In addition, the lipid quality of the Soxhlet‐extracted oil from the dried material was analysed. The drying condition of 70 °C and 10 h was the most suitable, because it preserved 98.7% of the original content of omega‐3. The dry material presented 14.7% of lipids and 58% of protein, and it was microbiologically safe. The Soxhlet extraction, in spite of using high temperature, did not promote the oxidation of polyunsaturated acids. The applied drying process, followed by Soxhlet extraction, yielded 7.6 g of omega‐3 fatty acids per kg of fresh sample. These results indicate that this residue presents large potential for oil extraction.     

Effect of black tea, garlic and onion on corn oil stability and fatty acid composition under accelerated oxidation

Fresh black tea, garlic bulbs and onion skin were macerated in refined corn oil to evaluate their antioxidant properties and the effect of heat on oil stability and fatty acid composition in accelerated oxidation experiments at 55 ° and 140 °C. At the lowest temperature control and onion treatments showed an induction time of 3 days with maximum peroxide values of 62 and 45 meq kg^?1, respectively. Addition of black tea and garlic increased oil stability with peroxide values of 5 meq kg^?1, without appreciable changes in the fatty acid composition. Heating at 140 °C for 48 h produced an accelerated deterioration of corn oil in all treatments. A reduction of polyunsaturated fatty acids of about 40% was observed, with high concentrations of non‐eluted materials which contained thermo‐oxidized substances. It was found that natural extract of black tea and garlic were effective to preserve corn oil under accelerated oxidation at 55 °C which simulates oil behaviour during storage, but cannot reduce the rate of oxidation at frying temperatures.     

Fishmeal and oil from lantern fish (Myctophidae) with special emphasis on protein quality

Fishmeal made from lantern fish (family: Myctophidae; genus: Benthosema pterotum) had proximate, mineral, amino acid and fatty acid composition within the range reported for fishmeal made from conventional fish. Similarly, the pressed-out oil had a fatty acid composition and content of unsaponifiables as reported for conventional fish oil. The content of unsaponifiables in the body fat of the fish indicated that wax esters contributed a minor part of the lipids of this species of lantern fish. Determined in chicks, the true digestibility of the amino acids varied from 92% (arginine) to 73% (hydroxyproline) which for most of the amino acids was 1-3% units lower than that found for a high-quality capelin fishmeal. No differences in rate of mortality, growth rate and feed consumption and utilisation were found between lantern and capelin fishmeal when they replaced increasing amounts (0 to 100%) of soya bean meal as protein supplements (72% of total protein) to cereal diets, both fishmeals reducing feed consumption and causing a significant improvement in feed utilisation compared with soya bean meal. The data indicate that lantern fish may be used for the production of fishmeal.     

Postharvest changes in physicochemical characteristics and free amino acids content of immature vegetable soya bean (Glycine max L.) grains

The aim of this study was to investigate the changes in physicochemical characteristics and free amino acid profile occurring in immature vegetable soya bbean during postharvest storage under three temperatures [5, 10 and 20 (control), ±1 °C] for 7 days. The results showed that a lower temperature provided an effective control in reducing weight loss, maintained firmness, delayed changes in the pod colour and soluble sugars concentration. Twenty‐two free amino acids in immature soya beans also identified by the ¹H NMR spectroscopy were strongly affected by postharvest temperature, and there were time‐specific differences in the concentration. Those significant differences in free amino acids concentration among storage conditions were closely associated with aspartate and glutamate degradation. Additionally, after 7‐day storage at 5 and 10 °C, the soya bean grains accumulated the highest amount of some essential and flavour amino acids, which revealed storage conditions selected should be dictated by the goal.     

GC-MS法结合酸酯化预处理测定不同地区油茶籽油脂肪酸含量

该研究在比较酸酯化和碱酯化预处理方法基础上,采用气相色谱-质谱联用（GC-MS）技术,对湖南、广东、江西、云南、广西、海南6个地区油茶籽油的脂肪酸种类、相对含量和比例进行了分析。结果显示,除油酸、芥酸、二十三碳酸和二十四碳烯酸外,酸酯化和碱酯化法处理后检测出的其他脂肪酸之间均存在显著差异（p<0.05）,且酸酯化法更适合茶油脂肪酸检测。茶油中肉豆蔻酸、十七酸、亚麻酸、花生酸、芥酸和二十四碳烯酸的最高含量均来自于湖南茶油样品,分别为0.10%、0.11%、0.20%、0.09%、0.17%和0.07%;棕榈烯酸含量最高的是广东茶油样品,为0.12%;棕榈酸含量最高的是广西茶油样品,为12.97%;亚油酸含量最高的样品产自江西,达15.58%;硬脂酸和油酸含量最高的样品均源自于海南,分别为3.74%和73.70%。油茶籽油在不同的产地其营养特性各不相同,广东和江西茶油的多不饱和脂肪酸含量最高,分别为15.33%和15.67%;云南茶油脂肪酸总不饱和程度最高,达85.74%;湖南和海南茶油稳定性较好,易于保存。该研究为了解我国油茶各主产区的茶油营养价值差异提供理论依据和参考信息。     

棉籽油脂肪酸甲酯化的方法及其脂肪酸含量分析

以新陆早39号以及新陆早50号的棉籽为材料,利用索氏提取仪提取其总油脂,分别采用三种常用的脂肪酸甲酯化方法:KOH-甲醇法,H₂SO₄-甲醇,14% BF₃-甲醇法进行甲酯化后,GC-MS上机分析;通过37种脂肪酸甲酯混标制定标准曲线,用外标法进行定量。结果表明:KOH-甲醇法甲酯化的脂肪酸GC-MS上机分析能检测到10种脂肪酸组分;H₂SO₄-甲醇与14% BF₃-甲醇法只能检测到6种。用KOH-甲醇法甲酯化后GC-MS测定表明,棉籽油脂肪酸以多不饱和脂肪酸的亚油酸为主,其次是饱和脂肪酸的棕榈酸以及单不饱和脂肪酸的油酸。在新陆早39号以及新陆早50号中,每克棉籽中亚油酸的含量分别达147.29 mg与163.2 mg,分别占其油脂含量的60.12%与60.83%;棕榈酸含量分别为65.05 mg与62.28 mg,分别占其油脂含量的26.55%与23.24%。油酸含量分别为24.79 mg与22.19 mg,分别占其油脂含量的10.12%和8.28%。结论:三种常用的脂肪酸甲酯化方法中,KOH-甲醇法更方便,快速,检测种类多,适用于棉籽脂肪酸的甲酯化。