Institute of Food Chemistry, University of Hohenheim, Garbenstraße 28, 70599 Stuttgart, Germany.
Institute of Food Chemistry, University of Hohenheim, Garbenstraße 28, 70599 Stuttgart, Germany.
J Chromatogr A. 2020 May 24;1619:460946. doi: 10.1016/j.chroma.2020.460946. Epub 2020 Feb 4.
Emulsifiers of the type E 472 are esters of fruit acids and mono- and diacylglycerols (MAG and DAG), which are used to adjust techno-functional properties in various food products. The most dominant representatives of E 472 emulsifiers are acetic acid esters (E 472a), lactic acid esters (E 472b), citric acid esters (E 472c), and mono- and diacetyl tartaric acid esters (E 472e). For the determination of fruit acids, a high-performance liquid chromatography method with ultraviolet light (HPLC-UV) detection was developed. Free and total fruit acids were determined by reversed phase HPLC-UV analysis of untreated and saponified emulsifier extracts with 20 mM potassium hydrogen phosphate buffer (pH 2.6) as isocratic eluent. Limits of quantitation of 0.08-0.27 g free fruit acid/kg emulsifier and 4-14 g total fruit acid/kg granted a reliable method with recoveries for free and total fruit acids between 80 and 100% with relative standard deviations (%RSD) below 4%. For the quantitation of free glycerol by spectrophotometry, an enzymatic assay was optimized for the analysis of E 472 providing reliable results with %RSD values below 9%. In addition, the ash content of E 472 emulsifiers was determined.
类型 E 472 的乳化剂是水果酸和单、二酰基甘油（MAG 和 DAG）的酯，用于调整各种食品产品的技术功能特性。E 472 乳化剂的最主要代表是乙酸酯（E 472a）、乳酸酯（E 472b）、柠檬酸酯（E 472c）和单、二乙酰酒石酸酯（E 472e）。为了测定水果酸，开发了一种带有紫外光（HPLC-UV）检测的高效液相色谱法（HPLC-UV）。未处理和皂化乳化剂提取物用 20mM 磷酸氢钾缓冲液（pH 2.6）作为等度洗脱剂，通过反相 HPLC-UV 分析来测定游离和总水果酸。定量下限为 0.08-0.27g 游离水果酸/kg 乳化剂和 4-14g 总水果酸/kg，保证了回收率在 80-100%之间、相对标准偏差（%RSD）低于 4%的可靠方法。对于分光光度法测定游离甘油，优化了用于分析 E 472 的酶法测定，得到了可靠的结果，%RSD 值低于 9%。此外，还测定了 E 472 乳化剂的灰分含量。
