Supercritical fluid extraction of fungal oil using CO2, N2O,CHF3 and SF6

The extraction of oil from fungi (Mortierella ramanniana var.angulispora) was studied using carbon dioxide (CO₂), nitrous oxide (N₂O), trifluoromethane (CHF₃) and sulfur hexafluoride (SF₆) under supercritical conditions. The oil solubility was highest in SC-N₂O followed by SC-CO₂, while both SC-CHF₃ and SC-SF₆ showed poorer solvent power. The recorded oil solubilities at 333 K and 24.5 MPa were 2.3 wt% in N₂O, 0.48 wt% in CO₂, 0.0099 wt% in CHF₃ and 0.0012 wt% in SF₆. The oil solubilities in SC-N₂O and SC-CO₂ were measured over the pressure range 15.7–29.4 MPa and at temperatures ranging from 313–353 K. N₂O always showed greater solvent power than did CO₂ at the same temperature and pressure. The solvent power of a supercritical fluid increases with density at a given temperature, and increases with temperature at constant density. The change in neutral lipid composition of the extracted oil with the extraction ratio was measured. Free fatty acids or diglycerides were extracted more easily than triglycerides or sterol esters. The change in fatty acid composition was also measured. The proportion of γ-linolenic acid in the extract remained constant throughout the extraction.     

Extrusion deactivation of rice bran enzymes by pH modification

Rice bran is considered in Mexico as “waste”, useful only for feeds. As considerable amounts of oil are available in rice bran, it might be worthwhile to stabilize it and extract the edible oil before using it for feedstuffs. Precisely these oils are responsible for rice bran rapid deterioration, particularly in climatic conditions such as those prevalent in Mexico's tropical areas (high humidity and high temperature). This paper deals with the study of the effect of pH during extrusion of fresh rice bran in order to inactivate lipid‐breaking enzymes. Hydrochloric acid or calcium hydroxide, Ca(OH)₂, were added at 0, 1, 5, 10% (dry basis), and moisture content of the bran samples was varied (20, 30, 40%, dry basis) in a 3² factorial design to corroborate its effect at acid and alkaline pH range. Free fatty acids (FFA) increase was the control variable. Extruded samples were stored at room temperature (between 20 and 28 °C) using a non‐extruded sample as control to assess the shelf life effects. Results indicate that in acid‐extruded samples, the increase in FFA concentration after 98 days was much less than in the unmodified‐pH or alkaline samples. The lowest FFA increase after 3 months of storage time was <10 mg FFA/g rice bran using extrusion with no water or chemicals added or using extrusion adding HCl, irrespective of the moisture content of rice bran.     

Ether lipids based on the glyceryl ether skeleton: Present state,future potential

Lipids from natural sources consist mainly of saponifiable substances, such as glycerides, along with some unsaponifiable lipids, some of which are ether lipids. Typical ether lipids are monoalkyl ethers of glycerin, also called alkyl/alkenyl glyceryl ethers. Alkyl/alkenyl glyceryl ethers have also been reported in marine organisms and in human feces. Several chemical syntheses of such ether lipids have been reported. Typical examples are alkyl glyceryl ether formation by the addition reaction of alkyl glycidyl ether and the telomerization reaction of butadiene with glycerin and a transition metal catalyst. Characteristic chemical structures, such as terpene alkyl glyceryl ethers, archaebacterial macrocyclic ether lipids, and glyceryl ethers of condensed cyclic planar molecules, have been obtained as well. Over the past few decades, industry has shown much interest in the chemistry and application of highly branched fatty acids. For example, isostearyl glyceryl ether (GE-IS) with methyl branching in the middle chain was already known, but it is now prepared at an industrial scale by proprietary alkyl glycidyl ether methods. The characteristic behavior of GE-IS toward water, such as formation of water-in-oil emulsions containing large amounts of water and of liquid crystals, has made it applicable for use in hair and skin-care cosmetics. Based on these studies and considerations, glyceryl ether lipids, which are rarely investigated, may become one of the most important and useful lipids in the industry.     

核桃油对小鼠血脂及胆固醇的影响

采用不同剂量的核桃油对小鼠进行试验，研究其对血脂水平的影响。结果表明，核桃油试验组小鼠的血清甘油三脂（TG）、总胆固醇（TC）和动脉硬化指数（AI）均不同程度低于高脂模型组（P〈0.05或P〈0.01），而高密度脂蛋白（HDL-C）却显著（P〈0．05）高于高脂模型组，表明，核桃油确有显著降低血脂和降低动脉硬化危险性的作用。     

传统金华火腿加工过程中皮下脂肪的变化

分别提取0、32d、60d、160d、240d的金华火腿中的皮下脂肪,分析其甘油酯、磷脂、游离脂肪酸的含量和脂肪酸组成。结果表明:甘油酯的含量从95.7%减少到85.4%,游离脂肪酸的含量从2.1%增加到14.3%,磷脂的含量没有发生显著性变化;甘油酯中的SFA有显著性变化,MUFA和PUFA无显著性变化;磷脂中的SFA、MUFA和PUFA都没有显著性变化;游离脂肪酸中,PUFA的含量显著减少,MUFA的含量减少,但其变化不显著,SFA的含量显著增加。     

米糠甾醇对非酒精性脂肪性肝炎大鼠的治疗作用

目的：研究米糠植物甾醇对非酒精性脂肪性肝炎（non-alcoholic steatohepatitis,NASH）大鼠的干预治疗作用。方法：实验选用50只健康SD雄性大鼠,随机分为正常对照组、NASH模型组和米糠甾醇低、中、高3个剂量组（65、130、195 mg/kg）。高脂饲料饲喂造模,各实验组同时进行米糠甾醇溶液灌胃干预。13周后观察各组大鼠肝组织病理学特点,测定血清中血脂总胆固醇、甘油三酯、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇含量和谷丙转氨酶、谷草转氨酶、一氧化氮合酶和超氧化物歧化酶活性,并比较各组肝脏指数和脾脏指数。结果：肝脏组织切片观察到NASH模型组有明显的肝细胞脂肪变性和炎症聚集浸润,米糠甾醇各治疗组肝组织病变呈现不同程度减轻。NASH模型组血清高密度脂蛋白胆固醇含量、超氧化物歧化酶、一氧化氮合酶、谷丙转氨酶和谷草转氨酶活性与正常对照组相比,均表现出明显异常;米糠甾醇各剂量组与NASH模型组比较,血清谷丙转氨酶显著降低（P＜0.001）、谷草转氨酶/谷丙转氨酶比值显著升高（P＜0.01）;低剂量组血清超氧化物歧化酶（P＜0.05）和一氧化氮合酶（P＜0.001）显著降低;中剂量组血清高密度脂蛋白胆固醇显著升高（P＜0.05）。结论：米糠甾醇对大鼠非酒精性脂肪性肝炎有预防与治疗作用。     

低温等离子体对动物源食品中脂质氧化作用研究进展

低温等离子体作为一种新兴非热杀菌技术, 具有广谱杀菌作用, 在食品杀菌保鲜领域已有广泛的应用研究, 因其含有大量活性自由基,在杀死微生物同时能够促进脂质和蛋白质氧化,对产品品质造成一定影响。本文重点概述了低温等离子体处理对牛肉、鸡肉、猪肉、水产品、油脂和乳脂等产品中脂质氧化作用; 总结了处理时间、处理功率、处理电压、贮藏时间以及样品中不饱和脂肪酸含量等因素对脂质氧化的作用。为降低低温等离子体处理对脂质氧化的促进作用,减弱因脂质氧化对产品品质造成的负面影响,添加抗氧化成为一种有效的途径,因此,本文针对添加天然抗氧化剂降低低温等离子体处理食品中脂质氧化程度的研究内容进行概括总结以及研究前景展望。通过低温等离子体处理条件对动物源食品中脂质氧化影响进行概述, 以及抗氧化措施总结和展望,可为低温等离子体在食品保鲜领域的深入研究以及工业应用提供理论参考。     

Chemo-Enzymatic Synthesis and Antimicrobial Evaluation of Alkyloxy Propanol Amine-Based Cationic Ether Lipids

The present study involved the synthesis and antimicrobial evaluation of alkyloxy propanol amine-based cationic lipids N,N-dimethyl-1-octadecylamino-3-alkyloxy-2-propanol (series A, 7a–e) and N-methyl-N,N-di-(2-hydroxy-3-alkyloxy-2 propyl) octadecylamine (series B, 9a–e) and their acetylated derivatives (8a–e and 10a–e). A simple three-step chemo-enzymatic approach was employed for the synthesis of 7a–e and 9a–e in 71–80 and 67–88 % yields, respectively. The first step involved the synthesis of a series of glycidyl ethers from a series of alcohols (C₄, C₈, C₁₀, C₁₂, C₁₄) which were opened in the second step with octadecylamine to obtain 1-octadecylamino-3-alkyloxy-2 propanol (5a–e) and N,N-di-(2-hydroxy-3-alkyloxypropyl) octadecylamine (6a–e). In the third step, alkyloxy propanolamines (5a–e, 6a–e) were quaternized using methyl iodide to yield quaternized ammonium salts. The quaternized ammonium salts were enzymatically acetylated using Candida antarctica lipase-B based immobilized enzyme Novozym 435 to obtain their acetylated derivatives. The quaternized salts as well as their acetylated derivatives were evaluated for antibacterial and antifungal properties. The title compounds were found to possess moderate to good antibacterial activities against all the studied bacterial strains namely, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Klebsiella aerogenes compared to streptomycin and cetyl trimethyl ammonium bromide (CTAB). The title compounds exhibited relatively good antifungal activities against Candida albicans and no significant activities against other fungal strains namely, Saccharomyces cerevisiae, Rhizopus oryzae and Aspergillus niger when compared to amphotericin B and CTAB.     

Diet and antiatherogenic aspects — a review

There is evidence that dietary changes could be associated with a significant decrease in blood lipids with a beneficial influence on all the risk factors of coronary heart disease (CHD). Dietary recommendations made for Americans do not appear to be suitable for Asians because most Asians are consuming a diet similar to the phase I diet advised by the American Heart Association (AHA). Several studies have demonstrated that foods such as guava, fish, fenugreek, mushroom, star gooseberry, onion, garlic, Bengal gram, blackgram, horsegram, redgram, parwar, konjac food, bitter gourd, oatmeal, soyabean, almonds, walnuts, elucine (ragi) and tapioca root can cause a beneficial change of blood lipids and decrease atherosclerosis. Several of these foods can also lower blood sugar, hyperinsulinemia and platelet‐aggregation. Banana, guava, musk melon, sweet lemon, lemon, tomato and star gooseberry may also diminish blood pressure. It has been demonstrated that a diet rich in these foods, if administered for a prolonged period, may cause a significant decrease in CHD and total mortality.