Antihyperlipidemic Effect of <Emphasis Type="Italic">Aronia melanocarpa</Emphasis> Fruit Juice in Rats Fed a High-Cholesterol Diet

Aronia melanocrpa fruit juice (AMFJ) used in our experiment was very rich in phenolic substances (709.3 mg gallic acid equivalents/100 ml juice). Anthocyanins (106.8 mg cyanidin-3-glucoside equivalents/100 ml juice) were the main flavonoid group. The aim of this study was to assess the influence of AMFJ on plasma lipids and lipoprotein profile, and histopathology of liver and aorta in rats with dietary-induced hyperlipidemia. AMFJ was administered by gavage for 30 days at doses of 5, 10 and 20 ml/kg body weight to rats fed a standard diet (SD) or a 4% cholesterol-containing diet (4% ChD). The 4% ChD caused a significant elevation of plasma total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG). AMFJ did not significantly influence plasma lipids in rats fed the SD and significantly hindered the elevation of plasma TC, LDL-C and TG in rats fed the 4% ChD. High-density lipoprotein cholesterol (HDL-C) levels were not significantly influenced either by the 4% ChD or by AMFJ. Neither the cholesterol feeding, nor AMFJ treatment induced any histopathological changes in rat liver and aorta. In conclusion, AMFJ showed an antihyperlipidemic effect in rats with hyperlipidemia and could be valuable in reducing this factor of cardiovascular risk.     

Effects of different dietary lipid sources in the diet for Pangasius hypophthalmus (Sauvage, 1878) juvenile on growth performance,nutrient utilization,body indices and muscle and liver fatty acid composition

Four isonitrogenous (300 g kg^?1 crude protein), isoenergetic (21 kJ g^?1) experimental diets were formulated to contain fish oil (FO), soybean oil (SBO), crude palm oil (CPO) and linseed oil (LO), respectively, as lipid sources each at inclusion level of 120 g kg^?1 and fed to triplicate groups of 15 juvenile iridescent shark, Pangasius hypophthalmus (Sauvage, 1878) (mean weight 10.00 ± 0.70 g) to apparent satiation twice daily for 12 weeks. The results showed that survival of fish was consistently over 95% for all treatments whereas growth performance in the SBO and CPO treatments was similar and significantly (P < 0.05) higher than for fish fed the LO diet. However, fish fed all vegetable oil‐based diets performed better than those fed the FO diet. Muscle and liver fatty acid composition for all treatments generally reflected the composition in the diet and the ratio of n‐3/n‐6 was found to play an important role in P. hypophthalmus, suggesting that excessive amounts of n‐3 fatty acids reduce the overall growth performance. Results of this study thus suggests that P. hypophthalmus fed diets containing vegetable oils (especially CPO and SBO) produce better growth than those fed FO diet without showing any signs of nutrient deficiency.     

中华绒螯蟹幼蟹蜕皮周期中肝胰腺和肌肉脂类的动态变化

以越冬后即将进入蜕皮的中华绒螯蟹幼蟹为实验对象,采用生化分析方法,研究其蜕皮周期肝胰腺及肌肉脂类的动态变化。本实验将其幼蟹蜕皮周期分为蜕皮前期(D期)、蜕皮期(E期)、蜕皮后期(AB期)和蜕皮间期(C1期和C2期)。结果发现,(1)蜕皮各期肝胰腺总脂含量变化显著,呈现为"高-低-高"的趋势,其中D期最高,AB期最低,C1、C2期开始回升;而肌肉总脂含量变化趋势与肝胰腺相反,为先上升后再下降趋势,在D期最低,AB期含量最高。(2)肝胰腺脂类中以甘油三酰(TG)为主,其次是磷脂(PL);而肌肉脂类主要是PL,其次是TG和胆固醇(CHO)。肝胰腺中TG含量为先下降后上升趋势,其中C1期含量最低,肝胰腺中的PL含量变化趋势与TC相反,AB期含量最高;肌肉中TG含量在E期最高,而此期的PL含量最低。(3)肝胰腺和肌肉的主要脂肪酸为C16∶0、C18∶1n9、C18∶1n7、C18∶2n6(LOA)、C20∶5n3(EPA)和C22∶6n3(DHA)(相对含量4%)。蜕皮周期内,肝胰腺中的饱和脂肪酸(SFA)、单不饱和脂肪酸(MUFA)和高度不饱和脂肪酸(HUFA)均表现为下降趋势,其中D期肝胰腺中的DHA和EPA含量最高;肌肉中的SFA和MUFA呈现为先上升后下降趋势,而肌肉中的PUFA和HUFA表现为先下降后上升趋势。研究表明,中华绒螯蟹幼蟹蜕皮周期中,肝胰腺和肌肉中的脂类成分发生了显著变化,肝胰腺中脂类可能是其蜕皮期间的主要能量来源物质之一。     

基于海洋硅藻的生物燃油生产

微藻与陆生作物相比,具有生物量大、生长周期短、脂质含量高、不占用耕地等特点,已成为生物燃油原料的首选。微藻生物燃油的经济性生产,需要建立能保持单一藻种优势的开放型微藻生产系统。采用海洋硅藻——角毛藻(Chaetoceros)作为讨论对象,综述了目前基于海洋硅藻的生物燃油生产系统设计所应用的技术:在开放型系统中生产硅藻,从生长介质中收获硅藻,从收获的硅藻中提取油脂和脂肪酸,以及整体的经济性。     

Effects of dietary fatty acid composition on metabolic rate and responses to hypoxia in the European eel (Anguilla anguilla)

European eels (Anguilla anguilla, L.) were fed on a commercial diet supplemented either with 15% by dry feed weight of menhaden oil (MO), an oil rich in highly unsaturated fatty acids of the n-3 series (n-3 HUFA), or with 15% by dry feed weight of coconut oil (CO), an oil composed primarily of saturated fatty acids (SFA). Following 90 days of feeding, the mean final masses of eels fed the two different oil supplements were similar, and higher than the mean final mass of a group fed the commercial diet alone. The diets created two distinct phenotypes of eels, distinguished by the fatty acid (FA) composition of their tissue lipids. Eels fed MO had significantly more total n-3 FA and n-3 HUFA in muscle and liver lipids than did eels fed CO, leading to higher n-3/n-6 and eicosapentaenoic acid/arachidonic acid ratios in the MO group. Measurements of O₂ uptake (M_O2) revealed that the MO group had a significantly lower routine metabolic rate (RMR) than the CO group. When exposed to progressive hypoxia, both groups regulated M_O2 at routine normoxic levels until critical water O₂ partial pressures that were statistically similar (9.62±1.08 kPa in MO versus 7.57±1.07 kPa in CO), beyond which they showed a reduction in M_O2 below RMR. The MO group exhibited a significantly lower M_O2 than the CO group throughout hypoxic exposure, but the percentage reductions in M_O2 below their relative RMR were equal in both groups. During recovery to normoxia, both groups exhibited an increase in M_O2 to rates significantly higher than their RMR. Throughout recovery, M_O2 was significantly lower in the MO group compared with the CO group, but the percentage increases in M_O2 relative to RMR were equal in both. During progressive hypoxia, neither group exhibited a marked ventilatory reflex response, both showed similar reductions in blood O₂ partial pressure and content, and similar increases in plasma lactate. The results indicate that, although the n-3 HUFA-enriched MO group had a significantly lower routine metabolic rate than the CO group, the difference in aerobic metabolism did not influence the European eel's homeostatic regulation of M_O2 in hypoxia.     

三种不同海洋脂质对溃疡性结肠炎小鼠及其肠道菌群的影响

为了研究3种不同海洋脂质——二十碳五烯酸(eicosapentaenoic acid,EPA)、二十二碳五烯酸(docosapentaenoic acid,DPA)和二十二碳六烯酸(docosahexaenoic acid,DHA)对溃疡性结肠炎(UC)小鼠及其肠道菌群的影响,本实验采用葡聚硫酸钠(dextran su...     

驴乳营养成分研究进展

驴乳因其乳清蛋白、乳糖、溶菌酶、不饱和脂肪酸和VC含量较高而酪蛋白及脂肪含量较低的特点，被誉为人乳的理想替代品，同时具有低致敏性、抑菌性和抗癌活性等多种生理功能。本文介绍驴乳的营养成分特点，包括蛋白质、氨基酸、脂肪、矿物质、维生素等，并与人乳、牛乳、水牛乳、羊乳和骆驼乳进行比较，以期为驴乳的综合加工与利用提供参考。