贮藏过程中胡麻油主要脂肪酸含量及组成变化

利用气相色谱法分析胡麻油中主要脂肪酸的组成及含量,并采用加速氧化法对胡麻油在贮藏过程中主要脂肪酸含量和过氧化值的变化进行分析。结果表明:胡麻油的主要脂肪酸有亚麻酸、亚油酸、油酸、棕榈酸和硬脂酸,其中亚麻酸含量为53.6%;随贮藏时间的延长,胡麻油各不饱和脂肪酸含量下降,且下降程度随不饱和度的增大而增大,过氧化值降低,饱和脂肪酸含量基本不变。     

Effect of processing and storage on neutral lipids of buffalo meat

Three muscles viz. Triceps brachii (TB), Longissimus dorsi (LD) and Biceps femoris (BF) from different anatomical locations of adult male buffaloes were stored after broiling and pressure cooking under refrigerated (4°C) condition for 3, 6, 9 days and 30, 60, 90 days under frozen (-10°C) storage. At the end of each storage interval they were analysed for total lipids, cholesterol contents and glyceride fractions i.e. monoglycerides (MG), diglycerides (DG), and triglycerides (TG). Muscles differed significantly in total lipids as well as contents of all glyceride fractions. Muscle LD had significantly higher total lipid content than TB and BF. Muscles differed significantly in their esterfied cholesterol (EC) contents. Heat processing increased total lipids, cholesterol, MG, DG and TG contents of all the buffalo muscles studied. Total cholesterol contents remained unchanged during refrigerated and frozen storage. However, EC, MG, DG and TG contents declined during storage. The influence of anatomical locations on fatty acid composition of neutral lipids was observed. The ratio of unsaturated to saturated fatty acids increased due to cooking. A gradual decrease in mono- and polyunsaturated fatty acids was recorded during refrigerated and frozen storage.     

Changes in fatty acid composition and electrolyte leakage of ‘Hayward’ kiwifruit during storage at different temperatures

Exposure to low storage temperature induces changes in electrolyte leakage and fatty acids composition, in a way depending on the plant tissue. Those changes alter the response of the fruit to storage conditions. The influence of storage temperature on ripening, fatty acids composition and electrolyte leakage of ‘Hayward’ kiwifruit were investigated. Harvested fruit were stored at 0, 5, 10, 15 and 20 °C for 5, 12 and 17 days. Measurements of SSC, firmness, flesh colour, fatty acid composition and electrolyte leakage were performed during the experiment. Kiwifruit did not fully ripen during the 17 days storage at any temperature. The major fatty acid component in ‘Hayward’ kiwifruit consisted of linolenic, followed by oleic, palmitic, linoleic and stearic acid. Membrane permeability and unsaturated/saturated fatty acid ratio increased during storage in all treatments. The highest increase was during the first 5 days and at the lowest temperatures. The increase in unsaturated/saturated fatty acid ratio was caused mainly by a decrease in palmitic and an increase in oleic acids. Stearic, linoleic and linolenic acids had insignificant changes during storage. The main increase in electrolyte leakage and unsaturated/saturated fatty acid ratio occurred during the first storage days and at lower temperatures, probably as a response of the tissue to an adaptation to the new stress storage conditions.     

冻结及冻藏温度对小龙虾冻藏过程中脂质氧化的影响

本研究将小龙虾热烫后置于真空包装盒内,灌水并抽真空,分别于3 种冻结温度（－20、－40 ℃和－55 ℃）的冰柜内冻结至中心温度为－15 ℃,再于2 种冻藏温度（－20 ℃和－40 ℃）的冰柜中冻藏24 周,测定不同温度冻结和冻藏小龙虾肉的脂肪质量分数、游离脂肪酸（free fatty acids,FFAs）含量以及脂肪酸组成、过氧化值（peroxide value,POV）和硫代巴比妥酸反应物（thiobarbituric acid reactive substances,TBARS）值,探讨冻结及冻藏温度对小龙虾脂质氧化的影响。结果表明：随着冻藏时间的延长,6 组小龙虾的脂肪质量分数、不饱和脂肪酸（unsaturated fatty acids,UFAs）和多不饱和脂肪酸（polyunsaturated fatty acids,PUFAs）相对含量显著下降（P＜0.05）,FFAs含量和饱和脂肪酸（saturated fatty acids,SFAs）相对含量、POV、TBARS值总体显著上升（P＜0.05）。冻藏温度相同时,－20 ℃冻结的小龙虾肉的POV、TBARS值高于－40 ℃和－55 ℃,而FFAs含量和脂肪酸组成无明显差异;冻结温度相同时,－20 ℃冻藏小龙虾肉脂肪和FFAs含量、POV、TBARS值均明显高于－40 ℃冻藏组,UFAs和PUFAs含量低于－40 ℃冻藏组,SFAs含量高于－40 ℃冻藏组。结论：冻结温度－40、－55 ℃和冻藏温度－40 ℃均减轻了小龙虾肉脂质的水解和氧化程度。     

豆天蛾氨基酸及脂肪酸分析与评价

对豆天蛾幼虫氨基酸及脂肪酸组成进行了分析测定,结果表明:豆天蛾幼虫含有18种AA和8种EAA,EAA/TAA为53.34%,属于优质完全蛋白质昆虫。豆天蛾幼虫不饱和脂肪酸含量61.74%,其中亚麻酸和油酸的含量较高,亚麻酸含量高达34.11%;饱和脂肪酸含量36.43%,其中棕榈酸的含量较高。     

玉山黑猪肉营养特性分析

研究在优质肉生产中科学利用玉山黑猪这一优良地方猪种资源.对9头玉山黑猪的背最长肌中肌内脂肪、氨基酸、肌苷酸以及脂肪酸和背脂中的脂肪酸,从营养学角度进行分析评价.结果表明:玉山黑猪背最长肌中17种氨基酸总含量为19.16％,其中鲜味氨基酸和必需氨基酸占总氨基酸的比例分别为38.96％和44.78％,具有较浓的鲜味和较高的蛋白质“生物效价”,而且氨基酸评分结果表明玉山黑猪的必需氨基酸比例适宜,有利于人体吸收;玉山黑猪肉中肌内脂肪、肌苷酸含量分别为6.62％、2.99％,是其肉质鲜嫩多汁的物质基础;此外,玉山黑猪背最长肌和背脂的不饱和脂肪酸的比例都较高,其背最长肌亚油酸和亚麻酸的含量分别为12.73％和0.86％,表明玉山黑猪脂肪酸的营养价值比较高.     

气相色谱-质谱法定性定量测定糜子中的脂肪酸

采用气相色谱-质谱法对糜子中脂肪酸进行定性、定量分析。结果共鉴定出14 种脂肪酸,相对含量为96.9%,其中不饱和脂肪酸8 种（64.533%）,主要有亚油酸（12.371%）、油酸（44.157%）、亚麻酸（1.173%）等。可见糜子中脂肪酸主要以不饱和脂肪酸为主,是优质脂肪酸。通过回归方程计算得出：糜子中棕榈酸、油酸、硬脂酸、亚油酸、亚麻酸的含量分别为100.261、165.309、23.402、52.181、17.516 mg/100 g。通过与其他杂粮进行比较,结果表明糜子和小米、高粱、小麦、燕麦、水稻一样均含有硬脂酸、油酸、亚油酸、亚麻酸和棕榈酸等,不饱和脂肪酸含量高,富含亚油酸和亚麻酸;本研究可为糜子品质的进一步开发和研究提供理论依据。     

热水处理对近冰温贮藏鲜枣品质提高与膜脂代谢的相关性分析

以采后临泽小枣（Zizyphus jujuba Mill. cv. Linzexiaozao）为实验材料,探讨热水处理对近冰温贮藏鲜枣果实耐冷性与膜脂脂肪酸组分变化的影响。采后果实用60 ℃热水浸泡1 min,自然干燥后,装入带有若干小孔(孔径为2 mm)的聚乙烯塑料饭盒,置于(?1.5~?2)℃的冷库中贮藏,定期测定果实冷害指数、细胞膜透性、丙二醛(MDA)、脂氧合酶(LOX)活性及膜脂脂肪酸组分变化。与对照相比,贮藏50 d时,热水处理果实的冷害指数、相对电导率、MDA和LOX活性分别降低了7.56、17.93%、17.93 μmol/g·FW和15.84 U/g·FW,不饱和脂肪酸油酸(C_18:1)、亚油酸(C_18:2)和亚麻酸(C_18:3)的相对含量及膜脂脂肪酸不饱和指数(IUFA)、脂肪酸不饱和度(UFA/FA)分别增加了11.10%、9.13%、8.60%和55.17、0.65,饱和脂肪酸肉豆蔻酸(C_14:0)、棕榈酸(C_16:0)、硬脂酸(C_18:0)和花生酸(C_20:0)的相对含量也分别降低了54.10%、18.66%、17.93%和3.37%,且差异显著(P<0.05)。尤其是对照LOX活性与亚麻酸(C_18:3)的相对百分含量变化有极显著(P<0.01)的负相关性(r=?0.931)。结果表明,鲜枣在近冰温冷藏下发生冷害的程度与膜脂中亚麻酸（C_18:3）的相对含量变化存在相关性。热水处理抑制了鲜枣膜脂脂肪酸不饱和指数(IUFA)和脂肪酸不饱和度(UFA/FA)的下降,诱导膜脂中不饱和脂肪酸的降解速率减缓,从而维持较高的膜脂稳定性,使采后鲜枣近冰温贮藏的耐冷性增强。     

降温方法对不同成熟度鸭梨果肉脂氧合酶活性和膜脂脂肪酸的影响

为了探讨缓慢降温抑制采后鸭梨果实褐变的机理,研究了不同降温方法对不同成熟度鸭梨果肉脂氧合酶(LOX)活性及膜脂脂肪酸组分和含量的影响。结果表明:在贮藏期间,LOX活性缓慢上升,晚采果活性较高;缓慢降温抑制了LOX活性的升高和果肉褐变,对早采果影响明显。鸭梨果肉中含有月桂酸、豆蔻酸、棕榈酸、棕榈油酸、珠光酸、硬脂酸、油酸、亚油酸、亚麻酸,其中含量较多的是亚油酸、棕榈酸和油酸。推迟采收和缓慢降温提高了果肉的U/S值,缓慢降温提高了鸭梨果肉的亚麻酸及前期的亚油酸含量,在贮藏后期,随着LOX活性的升高,亚油酸、亚麻酸的含量减少,二者可能是LOX的反应底物。适当早采结合缓慢降温可提高鸭梨果肉膜脂不饱和脂肪酸含量和U/S值,抑制果肉褐变。     

冻藏条件对人乳脂质及挥发性风味物质的影响

以新鲜人乳为对照(0d),设置-18、-60℃和-60℃快速冷冻(-60℃(Q))3种冻藏条件分别冻藏60 d与180 d,通过测定脂质含量、非酯化脂肪酸(non-esterified fatty acids,NEFA)含量、脂质过氧化物(lipid peroxide,LPO)含量、脂肪酸组成、乳脂肪球微观结构及挥发性...     

Biochemical aspects of the lipids in Vitis vinifera grapes (Macabeo variety). Part 1. Linoleic and linolenic acids as aromatic precursors

The aim of this work has been to study the temporal evolution during the vegetative stages of the composition of linoleic and linolenic acids, lipoxygenase activity and C₆ aldehyde content in Macabeo grapes. Linoleic acid was found to be the main fatty acid, especially in skin and pips, and higher levels of linolenic acid have been found in the polar lipid fraction, and in the pulp. Lipoxygenase activity is higher during the semi-ripe stage, and the aldehydes are not direct products of lipoxygenase action. There appears to be no direct relationship between the contents of linoleic and linolenic acids, lipoxygenase activity and C₆ aldehydes in Macabeo grapes during their vegetative stages. All these results suggest that in addition to lipoxygenase other enzyme systems must be involved in the metabolic processing of unsaturated fatty acids to C₆ aldehydes.     

Changes in the Polyunsaturated Fatty Acid Content of Potato Tubers During Growth, Maturation and Storage

SUMMARY— Kennebec and Red Pontiac potatoes were analyzed for fatty acids at intervals during growth and maturation of the tubers and subsequent storage at 4°C. During storage linoleic and linolenic were almost the only polyunsaturated acids present, but during growth and maturation considerable amounts of unidentified polyunsaturated acids were found. The percentage of polyunsaturated acids in the dry weight of tuber decreased to a low value near harvest time and remained near this value throughout the 6.3-month storage period, except that the value in Pontiacs stored 19 days was somewhat high. The percent of polyunsaturates in the total fatty acid fraction also dropped to a low value during growth and maturation but increased somewhat during storage. For this reason it may be better, when practicable, to make dehydrated products from freshly-harvested rather than from stored potatoes.
Potato dice contained as much polyunsaturated acid as the tubers they were made from; potato flakes contained somewhat less. In both products the degree of unsaturation of the fatty acid fraction was the same as for the tubers. NO off-flavors were noticed when samples were reconstituted. Apparently little or no oxidation took place during the processing.     

Oil,micronutrient and heavy metal contents of tomatoes

In this study, oils, micronutrients and heavy metal contents of tomato seeds and tomato (Lycopersicon esculentum) fruits from different Turkish resources were determined. The tomato seed oil contains more than 84% unsaturated fatty acids, such as oleic acid, linoleic acid and linolenic acid. The fatty acid composition of tomato seed oil was similar to that of soybean oil. Under supercritical conditions, partial thermal degradation occurs on the double bonds of unsaturated aliphatic carbons chains in fatty acids. Linoleic acid was the major unsaturated fatty acid in tomato seed oil. The concentrations of metals (Pb, Cd, Fe, Cu, Zn, Na, K, Ca and Mg) were determined in tomato samples.     

8种枣核油脂肪酸组成及含量分析与比较

对8种枣核(贡枣、晋枣、骨头枣、北樱枣、秤砣枣、敦煌大枣、滩枣、鸡心枣)油的脂肪酸组成与含量进行分析。结果表明:8种枣核油共检出24种脂肪酸,包括13种饱和脂肪酸、11种不饱和脂肪酸;饱和脂肪酸主要为棕榈酸、硬脂酸,不饱和脂肪酸主要为亚油酸、油酸、棕榈油酸;秤砣枣核油不饱和脂肪酸含量最高,达到84.55%;北樱枣核油、秤砣枣核油、滩枣核油和鸡心枣核油中油酸和亚油酸含量较高;贡枣核油、晋枣核油、骨头枣核油和敦煌大枣核油的棕榈酸含量较高;贡枣核油中亚麻酸含量最高,达到3.57%。采用聚类分析、主成分分析及线性判别分析,通过枣核油脂肪酸组成和含量可以实现8种枣核油的有效分类与区分,为不同品种大枣的分类判别与枣种质资源研究提供了新方法。     

Total lipid content and fatty acid composition of the seeds of some Vicia L. species

The seed oils of eight Vicia species (Leguminosae) were investigated for their total lipid contents and fatty acid compositions. The seed lipid contents were found to be between 2.30 and 3.91%. The fatty acid compositions of these eight different species were determined by gas chromatography of the methyl esters of their fatty acids. The seed oils of Vicia species contain palmitic and stearic acids as the major component fatty acids, among the saturated acids, with a small amounts of myristic, pentadecanoic, arachidic and behenic acids. The major unsaturated fatty acids found in the seed oils were oleic, linoleic and linolenic acids.     

OXIDATION OF LIPIDS IN SARCOPLASMIC RETICULUM OF MUSCLES FROM PASTURE- AND GRAIN-FED CATTLE WITH OR WITHOUT VITAMIN E SUPPLEMENTATION

The effect of different α-tocopherol contents in sarcoplasmic reticulum (SR) membranes on lipid oxidation was investigated. Muscle membranes contain high contents of polyunsaturated fatty acids that are very susceptible to oxidation during chilled or frozen storage. SR was prepared from M. longissimus dorsi, M. semimembranosus and M. gluteus medius muscles of pasture- and grain-fed steers supplemented with vitamin E (0, 500 or 2500 IU α-tocopheryl acetate) for 105 -132 days. Vitamin E supplementation increased the α-tocopherol concentration in SR of grain-fed cattle but did not change that of pasture-fed cattle. SR from pasture-fed beef had more linolenic and less linoleic acid than that of grain-fed meat and, compared with the other treatment groups, SR of control grain-fed cattle was significantly more prone to lipid oxidation, corresponding with its lower α-tocopherol content. Thus, α-tocopherol content appears to play a major role in determining the extent of lipid oxidation in muscle membranes, especially in those from pasture-fed beef that contained more polyunsaturated fatty acids.     

蛋黄甘油三酸酯的脂肪酸组成分析

采用毛细管气相色谱法分析酶法制备的蛋黄甘油三酸酯的脂肪改组成及相对含量，结果表明：其主要合有棕榈酸、油酸、硬脂酸、亚油酸、棕榈油酸，此外还含有微量的亚麻酸、花生四烯酸和二十二碳六烯酸。不饱和脂肪酸超过60％，是一种极具开发价值的营养保健油脂。     

热处理对茶花鸡肌肉中脂肪酸组成的影响

为研究热处理对茶花鸡肌肉中脂肪酸组成的影响,本文以300日龄的云南本地茶花鸡公鸡的胸肌和腿肌为研究对象,采用气相色谱-质谱法(GC-MS)检测胸肌和腿肌中脂肪酸含量,对其脂肪酸含量进行差异分析。结果表明在茶花鸡肌肉中共检测出32种脂肪酸,其主要脂肪酸为油酸、棕榈酸、亚油酸、花生四烯酸、硬脂酸及肉豆蔻酸。在原料肉中,胸肌和腿肌中总脂肪酸含量分别为3242.41与10026.31 μg/g,部位间存在显著性差异(P<0.05);胸肌与腿肌中脂肪酸类型以不饱和脂肪酸为主,含量分别占32种脂肪酸总量的60.92%与63.55%。经热处理后,胸肌中总脂肪酸含量比加热前胸肌中降低了9.37%(P<0.05),腿肌中总脂肪酸含量比加热前腿肌中降低了22.15%(P<0.05);胸肌、腿肌中脂肪酸以不饱和脂肪酸为主,不饱和脂肪酸含量分别占32种脂肪酸总量的59.38%与61.20%;胸肌和腿肌之间脂肪酸含量差异显著(P<0.05),腿肌的饱和脂肪酸(SFA)、单不饱和脂肪酸(MUFA)、多不饱和脂肪酸(PUFA)含量与胸肌有显著差异(P<0.05)。可见,茶花鸡胸肌和腿肌脂肪酸含量存在显著差异,热处理对茶花鸡胸肌和腿肌脂肪酸组成有明显影响。     

牡丹籽油化学成分GC-MS分析

牡丹种籽经石油醚-乙酸乙酯(7:1)索氏提取,三氟化硼甲醇甲酯化后,用气相色谱-质谱联用技术对牡丹籽油组分进行分析;共鉴定37种成分,主要为亚麻酸、油酸、亚油酸、棕榈酸和硬脂酸,其中不饱和脂肪酸占总量83.42%,饱和脂肪酸占14.662%。     

油菜蜂花粉及其蜂粮的营养成分

本文以油菜蜂花粉及其蜂粮为研究对象,对其常规营养成分、氨基酸和脂肪酸组成进行测定,评价并比较二者的营养价值。结果表明:油菜蜂粮的水分、还原糖和粗脂肪含量显著高于蜂花粉(p<0.05),灰分、蛋白质和总黄酮含量显著低于后者(p<0.05);油菜蜂花粉及其蜂粮中含有8种必需氨基酸,蜂粮总必需氨基酸与总氨基酸的比值(EEA/TAA)显著高于蜂花粉(p<0.05),分别为37.80%和34.74%;油菜蜂花粉和蜂粮的饱和脂肪酸中棕榈酸含量最高,分别为33.81%、33.50%,不饱和脂肪酸中亚麻酸含量最高,分别为32.42%、38.22%,差异显著(p<0.05)。油菜蜂粮是一种优质的必需氨基酸和必需脂肪酸营养源,可以作为一种潜在的原料应用于功能性食品的开发。