应用扫描电镜研究脂肪乳剂在全营养混合液中的稳定性

The Stability of Fat Emulsion in Total Nutrient Admixture(TNA) by Electron Scanning Microscopy Measurement

目的通过用扫描电镜、光镜检查及结合肉眼观察评价脂肪乳剂在全营养混合液7d内不同温度下的稳定性。方法检查洁净室内配制的30个EVA3L袋在较长时间内脂肪乳剂颗粒的大小及混合液稳定性。该混合液在4℃、室温、40℃存放7d,每天肉眼观察、光学显微镜和扫描电镜检查,并测定其渗透压、pH值。结果穴1雪室温、4℃时,样本熔化观察显示,无脂肪乳剂分层或脂肪凝集现象,混合液pH值分别为6.40±0.03和6.54±0.15,7d后分别为6.37±0.05和6.48±0.13。光学显微镜和扫描电镜下显示,所有混合物颗粒无聚集,电镜测得脂肪颗粒直径在低温组为穴0.322±0.01雪μm,室温组为穴0.310±0.01雪μm,直径>0.5μm但<2.0μm的颗粒<1%,均差异无显著性穴P>0.05雪;(2)在40℃时,保存7d后肉眼可观察到脂肪乳剂分层现象,光学显微镜检查显示无凝集现象,混合后7d脂肪乳剂的颗粒平均直径>0.42μm,并出现直径在1.5～5.0μm的颗粒,表明在40℃时脂肪乳剂的颗粒的变化有统计学意义(P<0.05)。结论在室温或异常温度条件下,7d内脂肪乳剂在全营养混合液内是稳定的。

Objective To assess the stability of particle-size distribution of fat emulsion in total nutrient admixture(TNA).Method s Determine in vitro the particle-size distribution of fat emulsion in TNA in30EVA bags.The TNA were stored at different temperature(4℃,room temperature,40℃)for7days to observe the chang of particle-size distribution by visual inspection,microscopy,electron scanning micros copy measurment and to measure the pH,osmolality.Results(1)Under4℃and roo m temperature,no creaming was observed and general check,pH,osmlality of the samples were stable,the particle size0.322±0.01microns(98%)( P >0.05);(2)Under40℃ ,after7days,general check was all right,pH,osmolality were stable but t he particle size increased to0.42±0.03microns with even1.5～5.0mi cron particles existed( P <0.05).Conclusions Fat emulsion was stable in the total nutrient admi xture(TNA);the methods to assess the fat particle size using visual inspectio n,microscopy,electron scanning microscopy measurment were reliable.