中国农业科学 ›› 2016, Vol. 49 ›› Issue (11): 2183-2193.doi: 10.3864/j.issn.0578-1752.2016.11.014

• 贮藏·保鲜·加工 • 上一篇    下一篇

黄油的短程分子蒸馏及其分馏物组成与物化特性

高希西1,2,张书文2,芦 晶2,刘 鹭2,逄晓阳2,岳喜庆1,吕加平2

 
  

  1. 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
  • 收稿日期:2015-12-01 出版日期:2016-06-01 发布日期:2016-06-01
  • 通讯作者: 岳喜庆,E-mail:yxqsyau@126.com。吕加平,E-mail:lvjp586@vip.sina.com
  • 作者简介:高希西,E-mail:xixi910226@126.com
  • 基金资助:
    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)

Chemical Compositions and Physicochemical Properties of Milk Fat and Fractions Obtained by Short-Path Distillation

GAO Xi-xi1,2, ZHANG Shu-wen2, LU Jing2, LIU Lu2, PANG Xiao-yang2, YUE Xi-qing1, LÜ Jia-ping2   

  1. 1College of Food Science, Shenyang Agricultural University, Shenyang 110161
    2Institute of Agro-products Processing Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193
  • Received:2015-12-01 Online:2016-06-01 Published:2016-06-01

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。轻相分馏物与重相分馏物具有不同的结晶形态(5℃、24 h),前者为针状结晶,后者为密集的晶体颗粒,且随着蒸馏温度的升高,晶体逐渐变大。【结论】短程分子蒸馏能够对黄油进行有效的分馏分离,蒸馏温度对分馏效果影响显著,通过改变蒸馏温度可以使分馏物具有不同于黄油原样的化学组成和物化特性,进而具有不同的加工特性。

关键词: 黄油, 短程分子蒸馏, 脂肪酸组成, 物化特性

Abstract: ObjectiveMilk 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.MethodCommercial 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 micrographswere also measured.ResultThe 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 trend of approaching to milk fat with the increase of distillation temperature. Relative to milk fat, the slipping melting point of the distillate was depressed and that of the retentate was augmented, while both of them showed an increasing trend as the distillation temperature increased. There was a significant positive correlation (P0.01) between the concentration of long-chain fatty acids in the fractions and their slipping melting point, r=0.977. DSC results showed that the melting and crystallization peaks of fractions were offset to the high temperature area as the increase of distillation temperature which indicated that the melting and crystallization properties of fractions were different but changed regularly. Polarized light micrographs showed that the distillate and retentate had different fat crystals, the crystals formed on cooling at 5 for 24 h corresponded to spherulites for the retentate whereas the solid fat phase of the distillate corresponded to needle-shape crystals. 【Conclusion】 Milk fat could be fractionated effectively by short-path distillation and distillation temperature had a significant effect on the resulting fractions. Fractionation of milk fat by short-path distillation at different distillation temperatures is able to change the chemical compositions, physicochemical properties and processing properties of the fractions.

Key words: milk fat, short-path distillation, fatty acid composition, physicochemical properties