普通小麦类胡萝卜素组分的超高效液相色谱分离方法

类胡萝卜素是影响小麦面粉及面制品颜色和营养品质的重要因素。本研究以中麦175 (软质麦)和中优206 (硬质麦)的面粉为试验材料，旨在优化小麦类胡萝卜素提取方法，建立超高效液相色谱(ultra performance liquid chromatography, UPLC)测定其组分的技术体系。研究表明，用含0.1% BHT的正己烷∶丙酮(80∶20, v/v)混合液作为提取液，结合恒温振荡法(300转 min^–1, 35℃, 振荡1 h)的提取效果最好。以YMC C30胡萝卜素分析专用色谱柱(高100 mm, 直径4.6 mm, 粒径3 µm)洗脱，乙腈∶甲醇∶水∶三乙胺(81∶14∶5∶0.05, v/v/v/v)为流动相A，甲醇∶乙酸乙酯∶三乙胺(68∶32∶0.05, v/v/v)为流动相B，流速0.4 mL min^–1，柱温35℃，分离时间25 min；以二极管阵列检测器(photodiode array, PDA)在450 nm波长下，能有效检测叶黄素、玉米黄质和β-胡萝卜素3种组分。该技术体系可作为普通小麦类胡萝卜素组分及营养品质研究的有效方法。

Establishment of Ultra Performance Liquid Chromatography (UPLC) Protocol for Analyzing Carotenoids in Common Wheat

Carotenoids is an important criterion in the assessment of color and nutritional qualities of end-use products in common wheat. In this study, grain powders of Zhongmai 175 (soft wheat) and Zhongyou 206 (hard wheat) were used as samples to develop an optimal procedure for extraction and separation of carotenoids compositions extracted from flours using ultra performance liquid chromatography (UPLC). The most effective extraction of carotenoids extraction was obtained using the solvent system of N-hexane; acetone of 80:20 (v/v, 0.1% BHT w/v) under the oscillation condition of 300 rpm, 35ºC, and 1 h. The separation was conducted using YMC C30 Carotenoid column (100.0 mm × 4.6 mm, 3 µm) with photodiode array (PDA) detector, and the column was thermostated at 35°C. Under a gradient system consisting of acetonitrile: methanol: water: triethylamine (81:14:5:0.05, v/v/v/v) (A) and methanol: ethylacetate:triethylamine (68:32:0.05, v/v/v) (B) at a constant flow rate of 0.4 mL min^–1, the carotenoids of common wheat flour samples can be well separated in less than 25 min. Carotenoids were detected at 450 nm. All the present results provided useful information for carotenoids compositions and quality improvement.