紫米营养功能成分及其游离态与结合态组成的HPLC/LC-MS分析

Nutritional and functional components in purple rice and free and bond state compositions analyzed by HPLC/LC-MS

以墨江紫米为研究对象,采用CIE Lab、HPLC和LCMS等分析技术并结合GB/T 5009.3—2010、5009.4—2010和5009.9—2008标准检测方法,全面地分析了紫米中基本营养成分和功能活性物质,并研究其呈色特征,同时对紫米多酚酸、黄酮和花色苷类物质的游离态与结合态组成进行鉴定和定量分析。结果表明:在基本营养成分方面,紫米与普通白米相比含量差异较大。紫米的蛋白质含量较白米高23%、灰分含量较白米高31%,而淀粉含量低于白米约15%。测色仪的色泽表征表明紫米和白米在色度、透明度等外观品质方面有极大的色差。紫米总花色苷和游离态与结合态总多酚、总黄酮的含量均高于白米,且以游离态的多酚和黄酮为主。HPLC、LC-MS分析结果表明,紫米酚酸黄酮类物质主要包括原儿茶酸、绿原酸、香草酸、咖啡酸、表儿茶素、p-香豆素、芦丁和阿魏酸等;花色苷主要为矢车菊素-3-葡萄糖苷、锦葵-3-葡萄糖苷和芍药-3-葡萄糖苷。研究结果可为墨江紫米品质评价与鉴定,以及后续营养功能性紫米食品的开发提供方法学参考和科学依据。

CIE Lab, HPLC-DAD and I.C-MS techniques, combined with the national standards methods were applied to determine the basic nutrient and functional compounds of purple rice, and comparedwith the white rice. HPLC-DAD was used to quantitative analyze the contents of phenolics and flavonoids, and the main kinds of anthocya- nins were identified with LC-MS. As a result, there is a big difference on the content of basic nutritional compound： purple rice protein content is 23% higher than white rice, and ash content is 31% higher, but starch content is 15% lower than white rice. And great differences on color value, luminance and chromatic aberration have also been found by color spectrophotometer. On the other hand, purple rice has higher content of anthocyanin, total phenols and fla- vonoids than white rice, and mainly existed on free states. Based on HPLC and HPI.C-MS method, the phenolic acids and flavonoids were analyzed, mainly including protocatechuic acid, chlorogenic acid, vanillic acid, caffeic acid, epicatechin, p-coumarin, rutin and ferulic acid, and anthocyanins are mainly knapweed-3-glucoside, mallow 3-glucoside and peony-3-glucoside. This study may provide experimental basis for further quality evaluation method and develop- ment research on functional active substances in the purple rice.