栉孔扇贝和海湾扇贝脂质及其脂肪酸组成分析

以栉孔扇贝和海湾扇贝为研究对象,采用Folch法提取两种扇贝肌肉和内脏中的总脂,并对其脂质和脂肪酸组成进行分析。结果表明:两种扇贝的肌肉总脂含量显著低于内脏,且肌肉总脂以磷脂为主,而内脏总脂以甘油三酯为主。两种扇贝的脂肪酸组成特征为多不饱和脂肪酸(PUFA)>饱和脂肪酸(SFA)>单不饱和脂肪酸(MUFA),其中,PUFA以n-3系列为主,主要为C20∶5n-3(16.58%~19.00%)和C22∶6n-3(11.49%~21.18%);肌肉中的n-3/n-6比值高于内脏,尤其C22∶6n-3含量显著高于内脏(P<0.01)。同时从两种扇贝中鉴定出6种脂肪醛二甲基缩醛(DMA),总量在7.77%~11.20%,并以C18∶0DMA(3.05%~6.89%)和C20∶1DMA(1.55%~4.25%)为主,且肌肉中DMA含量高于内脏,表明两种扇贝总脂中含有丰富的缩醛磷脂,肌肉总脂中的缩醛磷脂百分含量高于内脏。     

海水养殖花鲈和淡水养殖花鲈肌肉脂肪酸组成和含量分析

采用Folch 液回流提取投喂相同配合饲料的海水养殖花鲈和淡水养殖花鲈背部肌肉脂质,脂质经氢氧化钾-三氟化硼法甲酯化后进行气相色谱分析。结果表明：海水养殖花鲈和淡水养殖花鲈肌肉脂肪酸组成存在一定差异。海水花鲈肌肉脂肪酸中单不饱和脂肪酸(MUFA)、n-3 系列多不饱和脂肪酸(PUFA)、EPA(C20:5 n-3)和DHA(C22:6 n-3)含量明显高于淡水花鲈,而饱和脂肪酸(SFA)、n-6 系列PUFA 和AA(C20:4 n-6)含量则低于淡水养殖花鲈。海水养殖花鲈和淡水养殖花鲈肌肉中n-6 和n-3 系列PUFA 比值分别为0.27 和0.42,均远低于HMSO(英国卫生部)推荐的最高安全限值(4.0)。     

不同类型膳食脂肪酸对肥胖小鼠肝脏及其血液中脂肪酸组成和代谢相关基因影响

目的探讨不同类型膳食脂肪酸对肥胖小鼠肝脏及其血液中脂肪酸组成及代谢相关基因的影响。方法 8周龄雄性C57BL/6小鼠随机分为7组,即对照组(喂基础饲料)、长链饱和脂肪酸(LCSFA)组(喂猪油高脂饲料)、中链饱和脂肪酸(MCSFA)组(喂椰子油高脂饲料)、n-3多不饱和脂肪酸(n-3 PUFA)组(喂亚麻籽油高脂饲料)、n-6多不饱和脂肪酸(n-6 PUFA)组(喂大豆油高脂饲料)、单不饱和脂肪酸(MUFA)组(喂橄榄油高脂饲料)和反式脂肪酸(TFA)组(喂8%氢化大豆油高脂饲料),每组10只,共干预16周,所有种类饲料总能量均相同,基础饲料脂肪供能比为10%,各高脂饲料脂肪供能比均为45%,喂养周期结束后,禁食12 h,麻醉后立刻解剖取出肝脏。采用气相色谱法分析肝脏及其血液中脂肪酸组成的变化,实时荧光定量聚合酶链式反应(PCR)检测肝脏脂肪酸代谢相关基因的表达,肝脏脂质沉积采用油红O染色法检测。结果与对照组比较,LCSFA组、MCSFA组、n-6 PUFA组、MUFA组和TFA组小鼠肝脏中均出现明显的脂质沉积,n-3 PUFA组小鼠肝脏未出现明显的脂质沉积。与对照组比较,LCSFA组小鼠肝脏及血液中总n-6 PUFA和总PUFA含量升高; n-3 PUFA组小鼠肝脏及血液中总n-3 PUFA和总PUFA含量增加,但总MUFA含量减少; n-6 PUFA组小鼠肝脏及血液中总n-6PUFA、总n-3 PUFA和总PUFA含量升高,但总饱和脂肪酸(SFA)和总MUFA含量降低; MUFA组小鼠肝脏及血液中总SFA含量减少; TFA组小鼠肝脏及血液中C18∶1 n-9t(TFA)含量升高;以上差异均有统计学意义(P0. 05)。LCSFA组和MCSFA组小鼠肝脏脂肪酸代谢基因固醇调节元件结合蛋白1(SREBP-1c) mRNA水平高于对照组和n-6 PUFA组,差异均有统计学意义(P0. 05)。结论小鼠肝脏及其血液中脂肪酸构成与其对应的膳食脂肪酸模式一致。不同类型脂肪酸高脂饲料可通过对相关基因的表达影响肥胖状态下肝脏的脂质代谢及脂质沉积。     

杂交鲍Haliotis discus hannai × Haliots discus discus体内食源性脂肪酸的标志分异

本文研究了底播增殖的杂交鲍的内脏团、肌肉和消化腺内的得到公认的几种食源性脂肪酸标志的分布特征,可为杂交鲍的长期食源的判别提供依据。同等大小的杂交鲍,其内脏团、消化腺和肌肉内的硅藻脂肪酸标志(∑C16/∑C18和C20:5n-3)之间无显著无差异;消化腺内的绿藻脂肪酸标志(C18:2n-6+C18:3n-3)显著高于肌肉中的(p5%);肌肉中的褐藻脂肪酸标志(C20:4n-6)显著低于肌肉内的(p5%);异养细菌脂肪酸标志(C18:1n-7/C18:1n-9)在同等大小的杂交鲍内脏团、消化腺和肌肉中无差异。内脏团脂肪酸标志受性腺发育的影响;肌肉内脂肪酸含量较低;消化腺中脂肪酸组成的季节变化由食物的季节变化所致且总脂含量较高。从影响脂肪酸组成的因素及测试方法的灵敏度来看,消化腺用于脂肪酸标志法判断杂交鲍的长期食源更适宜。     

蒸煮对不同品质鸭肥肝营养特性及脂肪酸组成的影响

研究3种不同品质的鸭肥肝在蒸煮后常规养分、脂肪酸组成及脂质过氧化的变化。结果表明:1)熟化增加了鸭肥肝中C12:0、总脂和丙二醛(MDA)的含量,降低了水分、蛋白的含量,对鸭肥肝中糖原的含量无影响;2)鱼油组肥肝熟化后,其SFA、PUFA、n-6PUFA、n-3PUFA、EPA、DHA均显著高于大豆油组肥肝(P<0.05),极显著高于玉米组肥肝(P<0.01);3)玉米组肥肝熟化后SFA和MUFA显著降低(P<0.05),PUFA、n-6 PUFA、n-3 PUFA显著升高(P<0.05),大豆油组肥肝熟化对这几种脂肪酸的影响不大,而鱼油组肥肝熟化后这几种脂肪酸含量均升高,其中n-6PUFA达到显著水平(P<0.05);4)熟化具有降低3种肥肝中EPA和DHA的趋势,EPA降低幅度以玉米组肥肝最大,DHA降低幅度以大豆油组肥肝最大。以上结果提示,鱼油组肥肝的食用价值最高。     

黄颡鱼和大鳍(鳢)肌肉及鱼卵中脂肪酸组成的比较

采用GC测定了黄颡鱼和大鳍(镬)的脂肪酸组成.结果表明:在两种鱼的肌肉和鱼卵中含有22种脂肪酸.在黄颡鱼肌肉中饱和脂肪酸占34.90%;不饱和脂肪酸中,单不饱和脂肪酸占51.37%,多不饱和脂肪酸占13.74%.在黄颡鱼卵中,饱和脂肪酸占26.76%,单不饱和脂肪酸占49.51%,多不饱和脂肪酸占23.73%.从大鳍(镬)来看,肌肉中饱和脂肪酸占26.97%,单不饱和脂肪酸占48.8l%,多不饱和脂肪酸占24.23%;鱼卵中饱和脂肪酸占30.75%,单不饱和脂肪酸占44.08%,多不饱和脂肪酸占25.17%.研究揭示了黄颡鱼和大鳍(镬)的肌肉脂质中以不饱和脂肪酸为主,是理想的食品.两种鱼的鱼卵还含有较高的花生四烯酸(C20:4n-6,ARA)、廿碳五烯酸(C20:5n-3,EPA)和廿二碳六烯酸(C22:6n-3,DHA)的比例,鱼卵的食用、加工值得进一步研究和开发.     

等鞭金藻生长和脂肪酸组成随Fe3+浓度变化的研究

研究了一种重要的海洋微量元素铁对等鞭金藻(Isochrysis galbana)生长和脂肪酸组成的影响.研究结果表明,等鞭金藻在天然海水中(铁浓度为0.5 μmol/L)生长缓慢,但当培养基中Fe3 浓度超过12.5 μmol/L时,等鞭金藻生长差异不显著.C18:2(n-6)和C18:3(n-6)占总脂肪酸的比例随着Fe3 浓度增加而下降,但C22:6(n-6)(DHA)随着Fe3 浓度增加而上升.Fe3 浓度在12.5～120.5μmol/L,多不饱和脂肪酸(PUFA)占总脂肪酸的比例显著下降(P＜0.05).DHA和PUFA含量(W/W)随着Fe3 浓度的增加先上升后下降,二者达到最大值时Fe3 浓度分别为62.5和24.5μmol/L.     

气相色谱法测宝石鱼鱼油中的脂肪酸组成

本文以宝石鱼为原料,利用气相色谱法来鉴定宝石鱼鱼油中的的脂肪酸组成,通过与标准脂肪酸色谱图比较共确定25种脂肪酸,其中以16:0、18:0、18:1n-9、18:2n-6、22:6n-3、20:4n-3、22:5n-3(EPA)和22:6n-3(DHA)。为主。     

青海高原牦牛肉宰后成熟过程中脂肪酸组成及含量变化分析

为研究青海高原牦牛肉宰后成熟过程中不同部位肉脂肪酸组成和含量变化及差异,本实验选取青海高原牦牛冈上肌、背最长肌和半腱肌3个部位肉,利用气相色谱-质谱法(GC-MS)检测3个部位肉宰后成熟0、1、2、3、5、7和14 d的脂肪酸组成及含量。结果发现,3个部位肉中均检测出22种脂肪酸,其中,饱和脂肪酸8种,单不饱和脂肪酸5种,多不饱和脂肪酸9种,且均随宰后成熟时间的延长呈先增加后降低的趋势。3个部位肉宰后成熟过程中的脂肪酸组成相同但含量有差异,n-6/n-3比值均在1.0~3.0之间,脂肪酸组成比例较好。通过对青海高原牦牛3个不同部位肉不同成熟时间的脂肪酸组成及含量进行主成分分析,发现3个部位0、1和2 d具有相似性,主要有n-6系和n-3系多不饱和脂肪酸亚油酸(C18:2n6c)、花生四烯酸(C20:4n6)、顺-8,11,14-二十烷三烯酸(C20:3n6)、二十二碳六烯酸(C22:6n3)和单不饱和脂肪酸反油酸;3、5和7 d具有相似性,此期间大多数饱和脂肪酸、单不饱和脂肪酸和多不饱和脂肪酸含量增加;14 d则不同于其他时间,主要是此期间产生了大量的γ-亚麻酸(C18:3n6)。     

GC/MS分析俄罗斯鲟鱼不同部位脂肪酸组成

通过Folch法提取俄罗斯鲟鱼不同部位总脂,采用GC/MS法对其脂肪酸组成进行分析。通过质谱数据库检索和标准品对照鉴定脂肪酸组成。研究表明,鱼肉、鱼卵、鱼皮、鱼腹中脂肪酸种类及含量类似,多不饱和脂肪酸含量均大于40%,其次为单不饱和脂肪酸(30%左右)和饱和脂肪酸(17%左右),多不饱和脂肪酸以9,12-十八碳二烯酸和DHA为主。鱼肉中总脂含量12.83%,其中,多不饱和脂肪酸为42.37%,EPA+DHA为17.25%;鱼卵总脂含量为14.46%,其中n-3脂肪酸为22.10%;鱼皮含有较高含量的n-6脂肪酸(19.43%);鱼腹总脂含量14.45%,含有较高含量的多不饱和脂肪酸(42.66%)和单不饱和脂肪酸(34.07%),EPA+DHA为17.38%;鱼鳔中未检测到n-3和n-6脂肪酸;鱼肝总脂含量为55.92%,单不饱和脂肪酸含量尤为突出,高达55.81%,以9-十八碳烯酸(49.82%)为主,饱和脂肪酸含量仅为17.24%;椎骨中总脂仅为0.09%。     

Lipid changes during germination of fenugreek seeds (Trigonella foenum-graecum)

Fenugreek seeds were germinated in the dark for 96 h. Total lipid extracts were prepared and found to decrease on germination. Ultraviolet, visible and infra-red spectra were estimated for the lipids of ungerminated and germinated fenugreek seeds. Free fatty acids (FFA), total chlorophyll and carotenoid pigments increased greatly after germination. On the other hand, triglycerides, phospholipids and unsaponifiable matter decreased. Determination of individual phospholipids showed that phosphatidylcholine (PC) and phosphatidylethanolamine (PE) constitute about 67% of the total phospholipids of ungerminated seeds. After germination PC and PE decreased whilst phosphatidic acid (PA) and phosphoglyceric acid (PG)—degradation products of phospholipids by phospholipases—increased. The fatty acid composition showed that the total unsaturated fatty acids decreased whilst the total saturated fatty acids increased on germination. The fatty acids 18:2 and 18:3 were the most abundant acids in the lipids of the ungerminated seeds and fell after germination from 41·2% to 31·8% and 23·2% to 14.4%, respectively. The minor constituent fatty acids 20:0, 22:0 and 20:1 increased by 3·3-, 3·0- and 7·8-fold, respectively after germination.     

Changes in fatty acid composition of sunflower (Helianthus annuus) seeds in response to time of nitrogen application,supply rates and defoliation

The fatty acid composition of sunflower (Helianthus annuus L ) seed oil was shown to respond to N supply rates and the time of N application in four glasshouse and two field experiments using five cultivars. Changes in individual fatty acids % total were smaller than those caused by differences in minimum temperatures during seed development but they were statistically significant. N supply rates before floret initiation affected the % fatty acid composition of mature seeds; the percentage of palmitic (16:0) and linoleic (18:2) acids responded positively to increases in N supply whereas % stearic (18:0) and oleic (18:1) acids responded negatively. The only fatty acid to respond to N supply rates between floret initiation and anthesis was 18:0 acid. The percentage of 18:1 responded positively and that of 18:2 acid negatively to high N supply rates after anthesis Responses to single N applications at different stages of plant development in the field confirmed these findings but results were more variable than in the glasshouse. Partial or complete defoliation at anthesis in the field caused the same changes in fatty acid composition as did a low N supply after anthesis. The results are difficult to interpret in terms of our current knowledge of lipid biosynthesis. N supply rates may affect the rate of hydrolysis of fatty acid complexes or their transport from the proplastid to the cytosolic compartment. There was no compelling support for the hypothesis that N supply rates bejore floret initiation were affecting fatty acid composition through their effects on other plant characters such as leaf mass, seed number or single seed weight.     

Analysis of factors affecting volatile compound formation in roasted pumpkin seeds with selected ion flow tube-mass spectrometry (SIFT-MS) and sensory analysis

Pumpkin (Cucurbita pepo and maxima) seeds are uniquely flavored and commonly consumed as a healthy roasted snack. The objective was to determine dominant volatiles in raw and roasted pumpkin seeds, and the effect of seed coat, moisture content, fatty acid ratio, total lipids, reducing sugars, and harvest year on volatile formation. Sensory was conducted to evaluate overall liking of seed variety and texture. Seed processing included extraction from the fruit, dehydration, and roasting (150 °C). Oil extraction was done using soxhlet, fatty acid profile using Gas Chromatography Flame Ionization Detector, and reducing sugars using 3,5-dinitrosalicylic acid and UV-spectroscopy. Headspace analysis of seeds was performed by selected ion flow tube-mass spectrometry (SIFT-MS). Volatiles dominating in raw pumpkin seeds were lipid aldehydes, ethyl acetate, 2,3-butandione, and dimethylsulfide. Compounds contributing to roasted aroma include alkylpyrazines and Strecker and lipid aldehydes. Overall, hull-less seeds had higher volatile lipid aldehydes and Strecker aldehydes. Seeds dehydrated to a moisture content of 6.5% before roasting had higher initial and final volatile concentrations than seeds starting at 50% moisture. Higher oil content resulted in higher lipid aldehyde formation during roasting with a moderate correlation between free fatty acid ratio and corresponding lipid aldehyde. Harvest year (2009 compared with 2010) had a significant impact on volatile formation in hull-less seeds, but not as much as variety differences. No significant correlation was found between reducing sugars and volatile formation. Sensory showed that hull-less seeds were liked significantly more than hulled seeds. PRACTICAL APPLICATION: Elucidation of aromatic flavor development during roasting with SIFT-MS provides information on flavor release and offers better control during processing. Knowledge of volatiles in raw and roasted pumpkin seeds and effects of seed coat, moisture content, seed composition, and harvest date will allow for better control over the production/storage/transportation process and a more educated decision during selection of a variety for production of pumpkin seeds in the snack food industry.     

Composition and properties of seeds and pods of the tree legume Prosopis juliflora (DC)

Seeds and whole pods of Prosopis juliflora were analysed for proximate composition, fatty acids, minerals and soluble sugars. Crude protein constituted 35 % and 10 % of the seeds and whole pods, respectively. Nitrogen free extracts (NFE) comprised approximately 45 % of the seeds and whole pods. In the case of the pods, sucrose represented approximately 75 % of the soluble sugars. The lipid of both the seeds and whole pods contained a relatively large proportion of unsaturated fatty acids with linoleic acid as the predominant fatty acid. Levels of the macronutrients Ca, Mg, K and P were relatively low in comparison with cultivated legumes. Alkaline extraction of the seeds and whole pods showed that more than 70 % of the proteins were extractable. Maximum precipitation of the proteins was observed in the pH range 4.0-4.5. Amino acid analysis of the isolated proteins showed relatively high levels of lysine (312mg g^?l N for the seed and 438 mg g^?l N for the pod protein) and adequate levels of valine, leucine, tyrosine and phenylalanine. Methionine was the most limiting amino acid. The in vitro enzymic digestibility of the proteins of Prosopis seed was comparable to that of proteins of other legume seeds.     

Nutritional, fatty acid and oil characteristics of different agricultural seeds

Recently increased attention has been given to the utilization of agricultural waste products to produce food, feed, fertilizer and as a raw material in certain industries. Such utilization could not only help maximize available resources but at the same time minimize waste disposal problems. Nutritional and oil characteristics of different seeds were investigated. On a dry basis protein contents of 43, 34, 16.1 and 36.9% and oil contents of 19, 50.6, 35.9 and 25.7% were found in maple, pumpkin, citrus and apple seeds, respectively. Determined food energy values averaged 626 kcal/100 g (26.2 kJ/g). The seeds were found to have valuable amounts of essential minerals. The major fatty acid composition was 18 : 2 (linoleic) at concentrations of 39.1, 58.9, 31.9 and 45.6% and total saturated fatty acids of 16.8, 19.7, 42.8 and 12.4% and cis, cis -PUFA contents were 34.1, 46.8, 19.8 and 45.6%, respectively, for maple, pumpkin, citrus and apple; no measurable amounts of trans fatty acids were found.     

黑老虎种子的营养成分分析及评价

为合理开发利用黑老虎种子,对其营养成分进行测定。结果表明：黑老虎种子营养成分丰富,以粗脂肪为主,粗蛋白质和糖类次之;黑老虎种子中多糖是由甘露糖、鼠李糖、葡萄糖醛酸、半乳糖醛酸、葡萄糖、半乳糖、木糖、阿拉伯糖及岩藻糖9种单糖组成,以半乳糖和阿拉伯糖为主;黑老虎种子富含不饱和脂肪酸,其占总脂肪酸含量的81.89%,其中亚油酸占不饱和脂肪酸含量的88.89%;黑老虎种子中氨基酸种类较为齐全,游离氨基酸和水解氨基酸均包含7种人体必需氨基酸;黑老虎种子中鉴定出25种挥发性成分,以萜烯类化合物为主;此外,黑老虎种子还富含钾、镁、磷、锰、铁、锌等矿质元素。黑老虎种子具有营养和药用价值,极具开发价值。     

Changes in the lipid and fatty acid composition during maturation of seeds of white mustard (Sinapis alba)

The oil content of the seeds of white mustard (Sinapis alba) was determined 3 weeks after flowering and at weekly intervals until seeds were matured. Examination of the lipid classes by quantitative t.l.c. showed that triglycerides were the major components at all stages and were accompanied by sterol esters, diglycerides and polar lipids; monoglycerides were only detected in the first 2 samples. The fatty acid composition of the total oil and the mono-, di- and triglycerides and sterol esters was determined by g.l.c. The 7 major fatty acids, namely palmitic, stearic, oleic, linoleic, linolenic, eicosenoic and erucic acids were present at all stages of maturity. The fatty acid composition of the triglyceride fraction was similar to that of the total oil whereas the mono- and diglycerides and sterol esters contained a relatively higher proportion of saturated fatty acids. Erucic acid, the major acid of the oil from mature seeds did not become the major acid until 35 days after flowering. The results are discussed in relation to pathways of lipid synthesis in higher plants.     

Effect of irrigation on lipid biosynthesis in maturing sunflower seeds

The effect of irrigation on lipid biosynthesis in maturing sunflower (Helianthus annuus L.) seeds has been studied. Restricted irrigation adversely affected the biosynthesis of polar lipids during initial stages and triglycerides at the later stages of seed development. The fatty acid composition remained unaffected by irrigation. A de novo synthesis of triglycerides and fatty acids has also been observed.     

Lipid composition of tropical seeds used in the Nigerian diet

The lipid and fatty acid composition of some Nigerian seeds have been investigated, since they constitute an omportant dietary component of teh local population.     

广西河池、百色和梧州油茶种子含油率和脂肪酸组成测定

选取广西油茶重点产区河池、百色和梧州的主要油茶品种普通油茶、岑溪软枝油茶及大果红花油茶的种子为原料,石油醚为溶剂提取油茶种子的油脂及测定含油率,利用气相色谱-质谱联用技术对不同油茶籽油试样的脂肪酸成分进行分析鉴定。结果表明：4个不同产地不同品种的油茶种子出仁率为53.29%～68.91%;干籽含油率为47.05%～59.51%;GC-MS共鉴定出14种脂肪酸,单不饱和酸含量为72.91%～80.11%,其中河池巴马软枝油茶籽油的单不饱和酸含量最高,为80.11%,主要成分是油酸;多不饱和酸含量为5.85%～9.14%,其中梧州岑溪软枝油茶籽油的多不饱和酸含量最高,为9.14%,主要成分是亚油酸;饱和脂肪酸含量为13.62%～17.95%,主要成分为棕榈酸和硬脂酸;同时,广西油茶籽油中含有少量的9,10-环氧-十八碳烷酸尚未见报道。