Abstract The effect of lyophilization and rehydration medium on a liposome system for conjugated linoleic acid (CLA) delivery was studied. Liposomes were prepared by ethanol injection method employing soy phosphatidylcholine and CLA isomers 9c, 11t and 10t, 12c. Two rehydration media were assessed: a food simulant (distilled water) and the original medium used for liposome preparation (ethanol: water 1:9). Rehydrated liposomes were characterized in size, morphology, CLA encapsulation efficiency and membrane fluidity, at 3 and 30 days of cold storage. CLA loaded liposomes presented better stability and lower size than control liposomes without CLA through storage time, regardless of the rehydration medium. These facts could be related with spin label EPR measurements: CLA disordered the outer part of the lipid bilayer increasing fluidity, and ordered the inner part of the bilayer decreasing fluidity, which indicates a more packed membrane in the hydrophobic region. In all cases Transmission Electronic Microscopy images showed nanometric sized and oligo-lamellar vesicles. Liposomes preserved CLA isomers with high encapsulation efficiency: no differences were noticed between fresh and lyophilized samples. No influence of rehydration medium was noticed for the majority of the studied parameters. We have successfully developed efficient liposomal systems for bioactive compounds delivery in food applications.

中文翻译：

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冻干对负载共轭亚油酸的食品级脂质体的影响

摘要 研究了冻干和再水化介质对共轭亚油酸 (CLA) 递送脂质体系统的影响。脂质体通过乙醇注射法制备，使用大豆磷脂酰胆碱和 CLA 异构体 9c、11t 和 10t、12c。评估了两种补液介质：食品模拟物（蒸馏水）和用于脂质体制备的原始介质（乙醇：水 1:9）。在冷藏 3 天和 30 天时，再水化脂质体的特征在于大小、形态、CLA 包封效率和膜流动性。与不含 CLA 的对照脂质体相比，在储存时间内，无论再水化介质如何，装载 CLA 的脂质体都表现出更好的稳定性和更小的尺寸。这些事实可能与自旋标记 EPR 测量有关：CLA 扰乱了脂质双层的外部，增加了流动性，并命令双层的内部降低流动性，这表明疏水区域中有更多的填充膜。在所有情况下，透射电子显微镜图像显示纳米尺寸和寡层状囊泡。脂质体以高封装效率保存了 CLA 异构体：新鲜样品和冻干样品之间没有发现差异。对于大多数研究参数，没有注意到再水化介质的影响。我们已成功开发出高效的脂质体系统，用于在食品应用中输送生物活性化合物。脂质体以高封装效率保存了 CLA 异构体：新鲜样品和冻干样品之间没有发现差异。对于大多数研究参数，没有注意到再水化介质的影响。我们已成功开发出高效的脂质体系统，用于在食品应用中输送生物活性化合物。脂质体以高封装效率保存了 CLA 异构体：新鲜样品和冻干样品之间没有发现差异。对于大多数研究参数，没有注意到再水化介质的影响。我们已成功开发出高效的脂质体系统，用于在食品应用中输送生物活性化合物。