机构地区:[1]沈阳农业大学食品学院,沈阳110161 [2]中国农业科学院农产品加工研究所,北京100193
出 处:《中国农业科学》2016年第11期2183-2193,共11页Scientia Agricultura Sinica
基 金:国家"十二五"科技支撑计划(2013BAD18B10);国家公益性行业(农业)科研专项(201303085)
摘 要:【目的】黄油复杂的组成、结构及加工特性使其在一些食品加工领域中的应用受到了限制。采用不同的蒸馏温度对黄油进行短程分子蒸馏,分析黄油及其分馏物的化学组成和物化特性的变化及相关性,为黄油的分馏及应用提供理论参考和技术方法。【方法】以市售黄油为试验材料,分别采用150、165、180、190、200、210、225和240℃8个蒸馏温度对黄油进行短程分子蒸馏,分析轻相分馏物得率与蒸馏温度的关系;利用气相色谱测定黄油及其分馏物中脂肪酸的种类及含量,并通过测定酸值、碘值、过氧化值、滑动熔点、DSC熔化曲线和结晶曲线等理化指标,以及在偏振光显微镜下观测其结晶形态,探究不同蒸馏温度对分馏物的化学组成和物化特性的影响。【结果】从165℃开始黄油得到分馏分离,轻相分馏物得率随蒸馏温度的升高而增加,从165℃时的1.19%增加至240℃时的36.89%。经过短程分子蒸馏后,分馏物的酸值和过氧化值发生不同程度的变化,但不具规律性;碘值呈现出重相分馏物普遍大于轻相分馏物的规律。短程分子蒸馏没有改变分馏物中脂肪酸的种类,但使其含量发生了一定规律的变化:轻相分馏物富含短中链脂肪酸(40%—60%),重相分馏物富含长链脂肪酸(65%—75%)和不饱和脂肪酸(约30%),与重相分馏物的碘值普遍大于轻相的测定结果吻合;蒸馏温度对分馏物中各类脂肪酸的组成比例有显著影响,随着蒸馏温度的升高,分馏物中各类脂肪酸的含量接近黄油原样。滑动熔点方面,重相分馏物>黄油原样>轻相分馏物,且分馏物的滑动熔点随蒸馏温度的升高而升高;长链脂肪酸(LCFA)的含量与滑动熔点之间存在极显著的正相关关系(P<0.01),相关系数r=0.977。DSC测定结果表明,随着蒸馏温度的升高,分馏物的熔化峰和结晶峰均向高温区域偏移,表现出不同但有规律的熔化特性和结晶特性。轻【Objective】Milk fat is not suitable for some food applications and has limited functionality because of its complex compositions, structures and processing properties. The objective of this study is to provide a technical method and theoretical reference for fractionation of milk fat through studying the chemical compositions and physicochemical properties and its correlation of milk fat and fractions obtained by short-path distillation in different distillation temperatures.【Method】Commercial milk fat was fractionated by short-path distillation at 150℃, 165℃, 180℃, 190℃, 200℃, 210℃, 225℃, and 240℃, respectively, and the relationship of distillation temperature and yield of distillate was analyzed. Fatty acid composition was determined by gas chromatography to study the effect of distillation temperature on the composition and properties of milk fat and its fractions. Acid value, iodine value, peroxide value, slipping melting point, DSC thermograms of melting and crystallization and polarized light micrographs were also measured.【Result】The lowest temperature that milk fat could be fractionated was 165℃. Distillate yield increased from 1.19% to 36.89% with the distillation temperature increased from 165℃ to 240℃. Acid and peroxide value of distillate and retentate obtained by short-path distillation had different changes with no regularity, while the iodine value of retentate was generally higher than that of distillate. Short-path distillation did not change the kinds of fatty acids in the fractions, but the concentration of certain fatty acid presented substantial differences: the distillate was enriched in short- and medium-chain fatty acids(40%-60%), while the retentate was enriched in long-chain fatty acids(65%-75%) and unsaturated fatty acids(about 30%), which was consistent with the result of iodine value. Distillation temperature had a significant effect on the content of fatty acids in the fractions and the concentration of all kinds of fatty acids showed a
分 类 号:TS225.2[轻工技术与工程—粮食、油脂及植物蛋白工程]
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