Moisture Loss and Lipid Oxidation for Precooked Ground-Beef Patties Packaged in Edible Starch-Alginate-Based Composite Films

Edible films of starch‐alginate (SA), starch‐alginate‐stearic acid (SAS), SA‐tocopherol, SAS‐tocopherol, tocopherol‐coated SA film, and tocopherol‐coated SAS film were evaluated for their effectiveness in maintaining quality of precooked beef patties stored at 4 °C. Patty weight loss, moisture loss, 2‐thiobarbituric acid‐reactive substances value, the formation of hexanal, pentane, and total volatiles of samples differed with film composition. SAS‐based films were more effective (P < 0.05) in controlling moisture loss than lipid oxidation. Tocopherol‐treated films were more effective (P < 0.05) in inhibiting lipid oxidation than were nontocopherol films. Most of the tested edible films were not as effective as polyester vacuum bags in retarding moisture loss and lipid oxidation.     

三种绿藻总脂肪和脂肪酸的测定

用重量法测定了三种绿藻的总脂肪含量、气相色谱法测定了它们的脂肪酸百分含量。结果表明,三种绿藻的总脂肪含量在17.69%～21.44%之间。亚心形扁藻和青岛大扁藻的脂肪酸组分中的不饱和脂肪酸以C18：3w3含量最多;微绿球藻则以C20：5w3含量最多。     

特种红曲对鹌鹑实验性脂肪肝的治疗作用

目的: 观察特种红曲对鹌鹑实验性脂肪肝的影响, 以确证其治疗效果。方法: 建立乙醇性脂肪肝鹌鹑模型, 测定给药前后的血脂和肝脂水平, 并进行肝脏病理组织学检查。结果: 特种红曲1. 6 g·kg^-1 给脂肪肝鹌鹑灌胃20 d, 可明显降低血浆总胆固醇(TC), 甘油三酯( TG) 和低密度脂蛋白( LDL) 水平( P<0. 01), 同时降低肝脏TC 和TG 水平( P <0. 01); 特种红曲0. 8 g·kg^-1 也可降低血浆TC 和LDL 水平( P <0. 05) 和肝脏TC 水平( P <0. 01), 并可使肝组织的脂变程度明显减轻, 部分动物的肝脏甚至完全恢复正常。结论: 特种红曲对实验性脂肪肝具有治疗作用。     

黄芩苷对庆大霉素致耳蜗螺旋神经节细胞损伤作用的影响

目的: 探讨黄芩苷(baicalin,BA)对庆大霉素(gentamicin,GM)致小鼠耳蜗螺旋神经节(spiral ganglion,SG)细胞毒性的拮抗作用。方法: 用MTT法检测庆大霉素对SG 细胞的毒性作用以及黄芩苷对此作用的影响,用紫外分光光度法分别测定各实验组SG 细胞总超氧化物歧化酶(T-SOD)活性,谷胱甘肽过氧化物酶(GSH-PX)活性以及丙二醛(MDA)含量。结果: 黄芩苷可显著抑制GM 所导致的SG细胞中T-SOD 和GSH-PX 活性降低及MDA 含量升高。结论: 黄芩苷通过清除耳蜗螺旋神经节细胞内氧自由基和抑制脂质过氧化反应,拮抗庆大霉素耳毒性作用。     

银曲胶囊对高脂血症大鼠血脂的影响

目的 观察银曲胶囊对实验性高脂血症大鼠血脂水平的影响。方法 大鼠用高脂饲料喂养2 周以造成脂代谢紊乱模型, 并根据体重或血清中总胆固醇水平随机分为模型组、血脂康组和银曲胶囊大、中、小3 个剂量组(0.5 、1.0 、2.0 g/kg)。采用预防和治疗给药, 通过测定大鼠血清中总胆固醇、甘油三酯等水平, 观察银曲胶囊对实验性大鼠血脂的影响。结果 在预防和治疗实验中, 银曲胶囊大、中、小3 个剂量组血清中总胆固醇、甘油三酯、低密度脂蛋白、极低密度脂蛋白等水平与模型组比较均有一定程度降低, 高密度脂蛋白水平略升高(P<0.05 或P<0.01)。结论 银曲胶囊对实验性高脂血症大鼠有一定的防治作用。     

Bola型表面活性剂2.Bola化合物囊泡

Bola型两亲化合物分子因具有中部是疏水基,两端为亲水基团的特殊结构,可在水中聚集形成单层类脂膜（MLM）和单分子层囊泡（MLM囊泡）。许多单分子层囊泡具有良好的热稳定性。具有两个不同亲水基团的bola化合物可形成内外表面分别由不同亲水基团组成的不对称单分子层囊泡。Bola化合物可以参与到普通两亲化合物所形成的双层类脂膜中并改变膜的稳定性,还可成为连接双层类脂膜内外的电子或离子通道。     

内源脂类对抗性淀粉RSⅢ形成的影响

以普通玉米淀粉为试验材料 ,先制备出低脂淀粉和无脂淀粉 ,经高温压热处理后 ,分别测定它们的抗性淀粉含量 ,发现内源脂类对抗性淀粉RSⅢ的形成有显著影响 .多量脂类的存在不利于抗性淀粉的形成 ,少量脂类的存在提高了抗性淀粉产率 ,甚至略高于无脂淀粉的产率 .故对淀粉适当脱脂有利于抗性淀粉的形成 .     

Simultaneous determination of lodine value and trans content of fats and oils by single-bounce horizontal attenuated total reflectance fourier transform infrared spectroscopy

A method for the simultaneous determination of iodine value (IV) and trans content from the Fourier transform infrared (FTIR) spectra of neat fats and oils recorded with the use of a heated single-bounce horizontal attenuated total reflectance (SB-HATR) sampling accessory was developed. Partial least squares (PLS) regression was employed for the development of the calibration models, and a set of nine pure triacylglycerols served as the calibration standards. Regression of the FTIR/PLS-predicted IV and trans contents for ten partially hydrogenated oil samples against reference values obtained by gas chromatography yielded slopes close to unity and SD of <1. Good agreement (SD<0.35) also was obtained between the trans predictions from the PLS calibration model and trans determinations performed by the recently adopted AOCS FTIR/SBHART method for the determination of isolated trans isomers in fats and oils.     

Electron spin resonance spectroscopy for determination of the oxidative stability of food lipids

Evaluation of the oxidative stability of food lipids based on the tendency of formation of radicals is shown to be possible using electron spin resonance (ESR) spectroscopy and the spin-trapping technique. Induction time can be determined for mildly accelerated conditions (50°C for lipid fraction from mayonnaise enriched with fish oil), and the length of the induction time decreases during storage and γ-tocopherol depletion. The protection by ethylenediaminetetraacetic acid against initiation of lipid oxidation is also detected in the new assay. For more oxidatively stable lipids (butter, rapeseed oil, dairy spread) the mildly accelerated conditions can be used in the assay, provided that difference in signal height for fixed times replaces determination of induction time. ESR spin trapping provides a sensitive method for evaluating the oxidative stability of food lipids. Detection of radicals in the lipid as an early event in oxidation allows mild conditions to be used, and future experiments should also include sensory evaluation in relation to determination of practical shelf life.     

Effects of La, Ce, Y and Tb ions on Free Radical Mediated Peroxidation of Human Erythrocyte Membrane

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