Comparing the fatty acid composition of organic and conventional milk

During a 12-mo longitudinal study, bulk-tank milk was collected each month from organic (n = 17) and conventional (n = 19) dairy farms in the United Kingdom. All milk samples were analyzed for fatty acid (FA) content, with the farming system type, herd production level, and nutritional factors affecting the FA composition investigated by use of mixed model analyses. Models were constructed for saturated fatty acids, the ratio of polyunsaturated fatty acids (PUFA) to monounsaturated fatty acids, total n-3 FA, total n-6 FA, conjugated linoleic acid, and vaccenic acid. The ratio of n-6:n-3 FA in both organic and conventional milk was also compared. Organic milk had a higher proportion of PUFA to monounsaturated fatty acids and of n-3 FA than conventional milk, and contained a consistently lower n-6:n-3 FA ratio (which is considered beneficial) compared with conventional milk. There was no difference between organic and conventional milk with respect to the proportion of conjugated linoleic acid or vaccenic acid. A number of factors other than farming system were identified which affected milk FA content including month of year, herd average milk yield, breed type, use of a total mixed ration, and access to fresh grazing. Thus, organic dairy farms in the United Kingdom produce milk with a higher PUFA content, particularly n-3 FA, throughout the year. However, knowledge of the effects of season, access to fresh grazing, or use of specific silage types could be used by producers to enhance the content of beneficial FA in milk.     

番木瓜籽油的营养特性及稳定性

以番木瓜籽为研究对象,采用溶剂提取法提取番木瓜籽油,运用GC-MS对番木瓜籽油脂肪酸组成进行分析,对其理化性质和脂溶性伴随物含量进行检测,并对其抗氧化活性及稳定性进行研究。结果表明:以正己烷为提取溶剂,番木瓜籽油得率为(28.62±0.27)%;番木瓜籽油富含不饱和脂肪酸(86.54%),主要是油酸((44.03±1.21)%)和亚油酸((42.25±1.32)%),脂溶性伴随物主要有β-谷甾醇((5.11±0.16) mg/kg)、菜油甾醇((0.33±0.02) mg/kg)、生育酚((150.41±3.13) mg/kg);此外,番木瓜籽油酸值(KOH)((1.25±0.15) mg/g)、过氧化值((0.25±0.04)mmol/kg)均符合GB 2716—2018要求;番木瓜籽油对DPPH自由基和羟自由基均有较好的清除效果,IC50值分别为9.21 mg/m L和0.53 mg/m L,同时还具有较好的储藏稳定性和热加工稳定性。番木瓜籽可作为一种潜在的油料资源。     

萌动芝麻及萌动芝麻油的品质研究

通过对温湿度的控制促使芝麻萌动,对不同萌动期芝麻的主要组分及萌动芝麻油的主要质量指标、脂肪酸组成、维生素E、芝麻木酚素含量进行测定,研究萌动对芝麻及芝麻油品质的影响。结果显示:控制萌动时间在6 h之内,芝麻的粗脂肪含量和粗蛋白含量降低幅度都很小,不会对出油率造成明显影响,同时对萌动芝麻油酸值和过氧化值的影响也不大。不同萌动期芝麻油脂的主要脂肪酸组成及含量相差不大,随萌动时间的延长,芝麻油中维生素E含量增加(9 h和17 h时,维生素E含量分别提高10%和20%),芝麻素、芝麻林素含量稍有降低,芝麻油的氧化诱导时间延长;萌动芝麻经高温焙炒水代法提取的芝麻油中芝麻酚含量明显提高(增幅30%以上)。芝麻经适度萌动和焙炒后所提取的芝麻油品质更优,特别是在芝麻酚和维生素E含量上显示出优势。     

金线鱼鱼鳞营养成分的分析研究

用等离子体发射光谱法、气相色谱-质谱联用分析法和高效液相色谱法分别测定了金线鱼鱼鳞中9种元素、6种脂肪酸和15种氨基酸的含量。结果表明:金线鱼鱼鳞中含有丰富且对人体健康有益的元素;含5种必需氨基酸(苏氨酸、赖氨酸、苯丙氨酸、亮氨酸、异亮氨酸);所含的脂肪酸主要是十六脂肪酸(棕榈酸)和9-十八碳烯酸(油酸),其含量分别占脂肪酸总含量的30.16%和15.17%;金线鱼鱼鳞营养价值高,具有开发利用价值。     

A comparison of the chemical composition of the seeds of linseed and pea cultivars grown in pure stands or mixtures

A three-year field experiment was conducted to compare the chemical composition of the seeds of two linseed-pea mixtures, that is the cv. ‘Flanders’ with the cv. ‘Ramrod’ and cv. ‘Barbara’ with cv. ‘Phönix’. The results indicate that the chemical composition of the seeds of the linseed cultivars was not significantly affected by the sowing method, indicating that the species traits of linseed are constant. The mixed sowing increased the content of threonine and proline in the protein of the Flanders cultivar seeds and slightly increased the protein content of the seeds of both linseed cultivars in the mixtures with pea.     

Dietary effects on growth,plasma lipid and tissues of rats fed with non‐conventional oil of Telfairia occidentalis

The nutritional value of Telfairia occidentalis seed and seed oil available in local market was studied in rats. The average values of the proximate analysis on dry matter basis were 203 g kg^?1 crude protein, 536.3 g kg^?1 fat, 39 g kg^?1 ash, 95 g kg^?1 crude fibre and 43.7 g kg^?1 carbohydrate, while the moisture content was 75 g kg^?1. The mineral analyses showed that T occidentalis seeds contain potassium (3280 mg kg^?1), sodium (1230 mg kg^?1), magnesium (60.8 mg kg^?1), calcium (60.8 mg kg^?1) and iron (13.0 mg kg^?1). The oil extracted from the seed sample showed physicochemical properties that suggest its suitability for edible and industrial uses. The oil contained high levels of unsaturated fatty acids, oleic and linoleic, which accounted for 63.22% of total fatty acids recovered, while palmitic acid (27.4% of the oil by weight) was the most prevalent saturated fatty acid in the oil. No trace of eleostearic acid was detected in the oil. The effect on physical appearance, weight gain, organ weight, tissue and plasma cholesterol and triacylglycerol levels was determined in rats fed a diet containing 5% T occidentalis oil. These were compared with those of rats fed a control diet (0% T occidentalis oil) over an 8 week study period. Weekly monitoring of the rats showed good physical appearance and steady weight increase. The test rats were not anaemic and no mortality was recorded. While there was a significantly higher (p < 0.05) level of cholesterol in the heart of test rats compared with the control, there was a significantly lower (p < 0.05) plasma cholesterol level, suggesting that T occidentalis seed oil can be used to lower plasma levels of cholesterol. Histological examination of the sections of the heart, liver, kidney and spleen of the test rats revealed varying degrees of pathology. These include artherosclerotic changes in the walls of vasa vasori and lymphatics in the heart and hyaline degeneration of myofibrils, fatty infiltration of hepatocytes, and glomerular and tubular degeneration in the kidneys. These lesions may have been due to the effect of fatty acids, especially erucic acid, in the seed oil, which at 1.24% (less that the 5% conventional allowable limit for edible oils) may be intolerable for rats and may be unsuitable for human consumption. The seed oil may be used for industrial purposes such as soap making, lubrication and cosmetics for which it is well suited. Copyright © 2004 Society of Chemical Industry     

Comparison of lipid content and fatty acid composition and their distribution within seeds of 5 small grain species

Barley, oats, rice, sorghum, and wheat, each with two genotypes, were sequentially abraded by an electric seed scarifier. The pearling fines (PF) and pearled kernels (PK) at each cycle were analyzed for lipid (mostly nonpolar) content and fatty acid (FA) composition. The oil content in whole or dehulled grains ranged from 2.18% of a wheat variety to 6.38% of an oat line. Compared with barley and wheat, rice, oat, and sorghum had higher relative % of C18:1 (31.60 to 36.64 compared with 12.15 to 15.61) and lower % of C18:2 (35.69 to 45.44 compared with 50.79 to 61.50). The relationship between oil content in PF and the cumulative level of surface removal essentially describes the distribution pattern of oil content within a seed. Barley, rice, and sorghum had a similar distribution pattern, characterized by a rapid rate of decreasing for the first few outer layers and then by gradual decrease to a flat value toward the inner core. In contrast, distribution within oats was characterized by a gradual reduction in oil content across the seed. The distribution of oil within wheat fell between the former 2 types. For all 10 grains, from seed surface to inner core, C16:0 and C18:0 increased, C18:1 and C18:3 decreased, and C18:2 changed slightly, providing a new reason for improved oxidative stability for pearled kernels. The differences in the changing intensity of FA composition among grain species correspond to those in oil distribution within a seed, while varietal difference in distribution patterns of content and FA composition of lipids within a species was insignificant. PRACTICAL APPLICATION: This study was the first to document fatty acid distribution across a grain seed. Results provide 2 major reasons for improved oxidative stability of pearled grains: reduced oil content and shift of fatty acids toward more saturated and less unsaturated composition.     

Fatty acid and triacylglycerol composition and thermal behaviour of fats from seeds of Brazilian Amazonian Theobroma species

Raw materials for cocoa butter substitutes, replacements or equivalents depend mostly on the unsteady supply from wild stands of plants, while there is no current supply of Neotropical origin. Seed fats from Theobroma species (T cacao, T bicolor, T grandiflorum, T obovatum, T subincanum, T speciosum, T sylvestre and T microcarpum, plus the closely related species Herrania mariae) were analysed for fatty acid and triacylglycerol composition by gas and liquid chromatography respectively, for iodine value, for melting point by open capillary tube and for solid fat content (SFC) by nuclear magnetic resonance. All Theobroma species had significantly lower palmitate levels than T cacao, except for T sylvestre and T speciosum, T microcarpum presented highly unsaturated fat (C18:2), while H mariae had high levels of arachidate. Fats from T sylvestre and T speciosum had a similar iodine value to T cacao and a higher melting point. No fat from the other species presented a similar melting profile to cocoa butter. T sylvestre and T bicolor were the most similar to T cacao but had a higher SFC at human body temperature. T sylvestre and T speciosum seed fats had more POP than cocoa butter. Fats from seeds of T speciosum, T sylvestre and T bicolor could be recommended as cocoa butter substitutes, while fats from species of the section Glossopetalum could be employed in products requiring fats with a lower melting point. © 2002 Society of Chemical Industry     

松籽油脂肪酸组成及分布特征分析

通过气相色谱法分析了松仁油的总脂肪酸组成及其上位置分布特点。结果表明,松仁油主要含有亚油酸（46.29%）、油酸（26.68%）和松籽油酸（13.84%）。sn2位置上的亚油酸（66.84%）和油酸（28.33%）含量高于sn1,3上的含量,但是Δ5系列多不饱和脂肪酸（Δ5-PUFA）主要分布在sn1,3位置上。Δ5-PUFA的存在和它们选择性地分布在sn1,3位等特点是包括红松籽油在内主要松属植物果实油脂的特点。松籽油主要由12种甘油三酯组成,其中含量比较多的是LLPi（24.13%）,OLL/LOL（17.87%）和LOPi（14.32%）。我们还对植物甾醇和维生素进行分析,结果显示松籽油含有141.64mg/100g的总植物甾醇和23.63mg/100g的总生育酚。      

苎麻籽油脂肪酸组成及其粕氨基酸组成分析

用气相色谱法对苎麻籽油脂肪酸组成进行了分析,同时用氨基酸全自动分析仪对苎麻粕进行分析,为苎麻籽的开发利用提供基础数据。结果表明,苎麻籽油中不饱和脂肪酸含量90%以上,多不饱和脂肪酸含量79%以上,亚油酸含量尤为丰富,达77.40%~78.84%;苎麻粕含17种氨基酸,总含量为209.02~278.46 mg/g,其中7种必需氨基酸占总氨基酸的32.06%~33.17%。     

苹果籽、南瓜籽饲料脂肪酸组成与团头鲂鱼体脂肪酸组成相关性研究

以团头鲂为研究对象,研究了苹果籽和2种南瓜籽(白色南瓜籽和黑色南瓜籽)作为饲料油源对团头鲂全鱼、肌肉、肠脂和肝胰脏脂肪酸组成的影响.结果表明:全鱼、肌肉、肠脂、肝胰脏与对应饲料的脂肪酸相关系数随油脂添加水平的升高而升高;鱼体脂肪酸组成受饲料影响程度由大到小依次为肠脂、肌肉、全鱼、肝胰脏;团头鲂可以将饲料脂肪中的亚油酸和亚麻酸合成n-6系列、n-3系A高不饱和脂肪酸,但团头鲂转化n-3系列的脂肪酸较弱,同时C22:6n-3(DHA)比C20:5n-3(EPA)对团头鲂生长更为重要.     

18种大豆种子蛋白质、氨基酸和脂肪酸的组成成分分析

对18种大豆种子蛋白质和氨基酸、总脂肪及脂肪酸组成进行了分析。结果表明:榆林地区的横山老黑豆和神木连枷条的蛋白质含量较高,山西地区的汾豆79氨基酸含量最高,东北地区的吉育82的总脂肪含量最高;GC-MS共鉴定出7种脂肪酸,其中亚油酸和油酸的含量较高,不饱和脂肪酸的含量均在70%以上,其中子洲小黑豆、靖边黑豆和晋豆19所提取的油中不饱和脂肪酸含量在80%以上。研究结果可为筛选更适合种植的大豆品种提供理论依据。     

Simple procedures to remove mimosine from young leaves, pods and seeds of Leucaena leucocephala used as food

The effect of boiling and soaking in water on the mimosine and protein contents of young leaves, pods and seeds of the tropical leguminous tree Leucaena leucocephala (leucaena) was investigated. It was observed that the soluble protein content in leucaena tissue was overestimated because of the presence of mimosine. A more accurate method of determining the soluble protein content in leucaena tissue containing mimosine was developed and used in this study. It was found that boiling removed mimosine from young leaves, pods and seeds of leucaena but it also reduced the amount of soluble protein significantly. Soaking in water for 24 h eliminated 97% of mimosine from young leaves, pods and split seeds of leucaena, and up to 20% of mimosine from the whole young seeds without significantly reducing the soluble protein content.     

超临界CO2萃取技术在油脂工业中的应用

综述了超临界萃取技术在油脂工业的应用现状，其中对油脂、脂肪酸、生育酚、胡萝卜素、磷脂、甾醇等萃取现状进行了分析，并对超临界技术的发展方向及其在油脂工业的应用前景进行了介绍。     

热处理方式对南美白对虾虾青素含量、氨基酸组成及脂肪酸组成的影响

热处理是南美白对虾的重要加工手段,本文通过研究蒸制和煮制对南美白对虾含水量、虾青素含量、氨基酸组成及脂肪酸组成的影响,探索不同的热处理方式对南美白对虾营养成分的影响。结果表明:蒸制和煮制均导致南美白对虾含水量降低;蒸制较煮制的南美白对虾具有更高的虾青素含量,蒸制6 min时虾青素含量最高,达58.00μg/g;蒸制和煮制后总氨基酸含量均明显提高(p<0.05),蒸制样品中的苏氨酸、缬氨酸、亮氨酸、异亮氨酸、苯丙氨酸、蛋氨酸等必需氨基酸含量均高于煮制样品;蒸制和煮制后单不饱和脂肪酸含量降低,而多不饱和脂肪酸含量则分别由鲜虾的33.32%增加到煮制样品的35.13%和蒸制样品的35.02%。因此,蒸制是南美白对虾的一种良好的热处理方式。      

Chemical composition and nutritional quality of sea cucumbers

BACKGROUND: The dried form of sea cucumbers has been a seafood and medicinal cure for Asians over many centuries. In this study the chemical composition and nutritional quality of eight common sea cucumbers (Stichopus herrmanni, Thelenota ananas, Thelenota anax, Holothuria fuscogilva, Holothuria fuscopunctata, Actinopyga mauritiana, Actinopyga caerulea and Bohadschia argus) were determined. RESULTS: All species except T. anax and A. caerulea had higher protein and lower fat levels. A. mauritiana and B. argus had less ash content. Glycine was the dominant amino acid found in all species, and content ranged from 126 to 216 mg g^?1 of crude protein. All species exhibited low lysine:arginine ratio and higher essential amino acid scores were obtained by threonine and phenylalanine + tyrosine. A. mauritiana had proportionally less saturated fatty acids (31.23%), and more monounsaturated fatty acids (45.64%) and polyunsaturated fatty acids (PUFA, 23.13%) than other species. Arachidonic acid (C20:4n‐6) was the major PUFA in all species. T. ananas, A. mauritiana and A. caerulea contained more n‐3 PUFA. The n‐3/n‐6 ratios of eight sea cucumbers species ranged from 0.25 to 0.61. CONCLUSION: Sea cucumbers are a seafood with high protein and low fat levels. The amino acid contents were similar but fatty acid profiles were different among species. The comparison showed that T. ananas, A. mauritiana and B. argus possessed higher nutritional values than other sea cucumber species. Copyright © 2010 Society of Chemical Industry     

柑橘籽油理化特性及脂肪酸组成研究

利用索氏抽提法从3种柑橘籽中提取油脂,并对柑橘籽油的理化特性进行了测定。利用气相色谱-质谱(GC-MS)联用技术对3种柑橘籽油的脂肪酸组成进行了分析和鉴定,每种柑橘籽油都分析鉴定出了10种脂肪酸,其中主要成分为亚油酸和油酸。柑橘籽油具有较高的营养价值,作为新油源具有一定的开发前景。     

江西地区油茶籽的含油率和脂肪酸组成的调查与分析

本文对江西地区2011年产的38个油茶籽的含油率和脂肪酸组成进行了分析。结果表明:油茶籽含油率在20.48%~49.84%之间,平均为37.07%。油茶籽油脂肪酸主要是由棕榈酸、硬脂酸、油酸、亚油酸、花生一烯酸等脂肪酸组成,棕榈酸含量平均值8.19%;硬脂酸含量平均值2.48%;油酸含量平均值81.02%;亚油酸含量平均值7.74%;花生一烯酸含量平均值0.46%,主要不饱和脂肪酸油酸和亚油酸含量平均达到了88.76%,说明江西地区的油茶籽油符合高品质食用油的标准。