花生四烯酸微胶囊稳定性的对比研究

采用Schaat烘箱法对3种花生四烯酸粉末油脂进行稳定性研究。在整个试验过程中,每2天分别对3种样品的色泽、气味、溶解性感官评定,并测定3种花生四烯酸的过氧化值,对比它们的稳定性。结果表明:样品1的色泽、气味变化较慢,溶解性较好;样品3的色泽、气味变化较快,溶解性较差。样品1的稳定性较好,样品2的稳定性适中,样品3的稳定性较差。可以选用样品1和样品2添加到婴儿配方奶粉中对其稳定性和含量进行试验,以完成对乳粉中添加营养强化剂种类的确定。     

(阿尔巴尼亚)塞拉内兹湖天然沥青改性加德士沥青的路用性能评价

采用湿法工艺,以阿尔巴尼亚塞拉内兹湖天然沥青为改性剂对加德士70号沥青进行了改性,分析了改性沥青的性质;以改性沥青为胶结料,进行了AC-13型混合料的拌制、检测。结果表明,与基质沥青相比,改性沥青针入度降低、软化点升高、表观黏度增大、高温等级提高而低温性能基本不变;动稳定度提高,车辙深度降低,冻融劈裂强度比增强,高温稳定性和水稳定性提高。     

Lipid content and fatty acid profile of Senegalese sole (Solea senegalensis Kaup, 1858) juveniles as affected by feed containing different amounts of plant protein sources

A growth trial with Senegalese Sole (Solea senegalensis Kaup, 1858) juveniles fed with diets containing increasing replacement levels of fishmeal by mixtures of plant protein sources was conducted over 12 weeks. Total fat contents of muscle, liver, viscera, skin, fins and head tissues were determined, as well as fatty acid profiles of muscle and liver (GC-FID analysis). Liver was the preferential local for fat deposition (5.5–10.8% of fat) followed by fins (3.4–6.7% fat). Increasing levels of plant protein in the diets seems to be related to increased levels of total lipids in the liver. Sole muscle is lean (2.4–4.0% fat), with total lipids being similar among treatments. Liver fatty acid profile varied significantly among treatments. Plant protein diets induced increased levels of C16:1 and C18:2 n−6 and a decrease in ARA and EPA levels. Muscle fatty acid profile also evidenced increasing levels of C18:2 n−6, while ARA and DHA remained similar among treatments. Substitution of fishmeal by plant protein is hence possible without major differences on the lipid content and fatty acid profile of the main edible portion of the fish – the muscle.     

Protective Effects of EPA and Deleterious Effects of DHA on eNOS Activity in Ea hy 926 Cultured with Lysophosphatidylcholine

Oxidized low density lipoprotein (Ox-LDL) is a well-established risk factor in atherosclerosis and lysophosphatidylcholine (LysoPtdCho) is considered to be one of the major atherogenic component of Ox-LDL. The purpose of this work was to investigate the effects of two membrane n-3 long chain polyunsaturated fatty acids (n-3 PUFAs), EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) compared to n-6 PUFA, ARA (arachidonic acid), on the activation of endothelial NO synthase (eNOS) by histamine in Ea hy 926 endothelial cells incubated during 24 h in the presence or the absence of LysoPtdCho. DHA (50 μM) produced a ROS induction in cells and aggravated the LysoPtdCho-induced oxidative stress. It did not modify the basal eNOS activity but impaired the stimulation of eNOS induced by histamine and was unable to correct the deleterious effect of LysoPtdCho on histamine-stimulated eNOS activity or phosphorylation of Ser 1177. In contrast, EPA (90 μM) did not modify the ROS level produced in the presence or absence of LysoPtdCho or basal eNOS activity and the stimulating effect of histamine on eNOS. However, it diminished the deleterious effect of LysoPtdCho as well as on the histamine-stimulated eNOS activity on the phosphorylation on Ser 1177 of eNOS. The beneficial effect of EPA but not DHA on endothelial eNOS activity in Ea hy 926 could be also partially due to a slight decrease in membrane DHA content in EPA-treated cells. Consequently, the equilibrium between NO generated by eNOS and ROS due to oxidative stress could explain, in part, the beneficial effect of EPA on the development of cardiovascular diseases. By contrast ARA an n-6 PUFA was devoid of any effect on ROS generation or eNOS activity in the basal state or after histamine-induced stimulation. In vivo experiments should be undertaken to confirm these results.     

Short-Term Stability of Whole Blood Polyunsaturated Fatty Acid Content on Filter Paper During Storage at −28 °C

Finger or heel‐pricked blood sampling for fatty acid analysis is suitable especially in newborn infants where blood sampling is difficult and phlebotomy for research can be unethical. The aim of this study was to evaluate dried blood long chain polyunsaturated fatty acids (LC‐PUFA) stability during storage at ?28 °C. We collected 12 blood cord samples that were analyzed immediately after blood drawing, with and without drying the blood on filter paper. Dried samples were then analyzed 7 days and 1, 3, and 6 months after collection. Butylated hydroxytoluene was added to all samples. Fatty acid composition and ¹³C enrichment were measured by gas chromatography and by gas chromatography‐isotope ratio mass spectrometry, respectively. The fatty acid composition, expressed in mol%, of the major LC‐PUFA at day 7 was not statistically different from time 0, however lower values were found by the first month of storage. The ¹³C enrichment of 20:4n‐6 and 22:6n‐3 did not differ during the whole study period. LC‐PUFA analysis from dried umbilical cord blood in neonates should be performed within a week, major losses of LC‐PUFA occur afterwards. However, fatty acids obtained from dried blood maintain their ¹³C enrichment value for up to 6 months and thus these samples are suitable for natural abundance isotopic studies.     

Health-promoting substances and antioxidant properties of Opuntia sp. fruits. Changes in bioactive-compound contents during ripening process

Several Opuntia cactus fruits of different pulp colours from Argentina were studied at their physiological mature states. Analyses of these fruits showed very variable total soluble solid values and ascorbic acid contents ranging from 0.26 to 0.48 mg/g. Total phenolic compounds contents were between 0.54 and 1.2 mg of gallic acid/g, respectively. Purple Opuntia spp., dark purple Opuntia ficus-indica and orange Opuntia megacantha presented the highest levels amongst the samples studied. The antioxidant activity of Opuntia fruits was very variable and presented vitamin C equivalent values (VCEAC) between 0.25 and 0.57 mg/g. Purple Opuntia ficus-indica showed the highest antiradical ability. Besides, the antioxidant activity, ascorbic acid and phenolic compound contents in yellow and orange Opuntia megacantha fruits were monitored in different stages during their ripening process. Concentration changes of betalains and chlorophylls comparing skin and pulp and other physicochemical parameters were also measured in these fruits.     

几种重要微生物油脂在食品及饲料工业中的应用

微生物油脂的经济可行性主要取决于其用途,目前微生物油脂已成为几种长链多不饱和脂肪酸的重要资源.对富含ARA、DHA和EPA的几类微生物油脂在孕婴食品、成人食品和水产饵料、饲料添加剂方面的应用进行了介绍.通过总结及展望,说明这几类微生物油脂将会在更多的配方食品中得到应用,微生物油脂产品的消费者将从特殊人群扩展到所有人群,并形成一个大产业.     

Decreases in Phospholipids Containing Adrenic and Arachidonic Acids Occur in the Human Hippocampus over the Adult Lifespan

One of the biggest risk factors for developing Alzheimer's disease is advanced age. Despite several studies examining changes to phospholipids in the hippocampus during the pathogenesis of Alzheimer's disease, little is known regarding changes to phospholipids in this region during normal adult aging. This study examined the phospholipid composition of the mitochondrial and microsomal membranes of the human hippocampus from post‐mortem tissue of neurologically normal subjects aged between 18 and 104 years. Many of the age‐related changes found were in low‐to‐moderately abundant phospholipids in both membrane fractions, with decreases with age being seen in many phospholipids containing either adrenic or arachidonic acid. The most abundant phospholipid of this type was phosphatidylethanolamine 18:0_22:4, which decreased in both the mitochondrial and microsomal membranes by approximately 20 % from ages 20 to 100. Subsequent decreases with age were seen in total adrenic and arachidonic acid in the phospholipids of both membrane fractions, but not in either fatty acid specifically within the phosphatidylethanolamine class. Increases with age were seen in the hippocampus for mitochondrial phosphatidylserine 18:0_22:6. This is the first report of changes to molecular phospholipids of the human hippocampus over the adult lifespan, with this study also providing a comprehensive profile of the phosphatidylcholine, phosphatidylethanolamine and phosphatidylserine phospholipids of the human hippocampus.     

Effect of dietary linseed on the nutritional value and quality of pork and pork products: Systematic review and meta-analysis

Nutritional quality of pork is a significant factor for consumers' health. Feeding n-3 PUFA to pigs, using linseed, improves pork nutritional quality. A meta-analysis involving 1006 pigs reported in 24 publications was carried out to assess the effects of dietary linseed on alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) content in muscle and adipose tissue. Data showed positive effects of n-3 PUFA on muscle fatty acid composition: ALA + 137%, EPA + 188%, DPA + 51% and DHA + 12%. Same results were observed in adipose tissue: ALA + 297%, EPA + 149%, DPA + 88% and DHA + 18%. A positive correlation between dietary treatment and ALA and EPA content in muscle (P < 0.001) and adipose tissue (P = 0.036) was observed. A significant association between DPA (P = 0.04) and DHA (P = 0.011) and live weight in muscle was observed. Feeding linseed to pig improves the nutritional pork quality, raising the n-3 PUFA content in muscle and adipose tissue.     

基于置信传播译码的DRA码设计

该文通过重复器、组合器、交织器的联合优化,设计了一种没有小环的双重复累积码(DRA码);基于EXIT图优化设计了该码的度分布。研究结果显示,这类DRA码的度分布灵活;当采用置信传播译码时,错误平层低。