Page 74 - 《广西植物》2020年第2期
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2 期              孙坤坤等: 低海拔地区黑苦荞酚类物质含量、组成及抗氧化活性研究                                           2 1 1

       Abstract: In order to explore the market value of black tartary buckwheatꎬ we analyzed the phenolics and antioxidant
       activities of Chuanqiao 1 and Jiujiang Kuqiaoꎬ two tartary buckwheat varieties planted in the low ̄elevation regions of
       the Jianghan Plain of Hubeiꎬ determined the contents of freeꎬ bound and total phenolics and flavonoidsꎬ and we ana ̄
       lyzed the antioxidant activities of their seed extracts in vitro using the DPPH free radicalꎬ ABTS free radical and iron
       ion reduction antioxidant (FRAP) assaysꎬ and we also determined the phenolic compositions of the seed extracts by
       the high performance liquid chromatography (HPLC). The results were as follows: (1) The contents of total phenolics
       and total flavonoids were significantly higher in the seeds of Chuanqiao 1 than those of Jiujiang Kuqiaoꎬ with the former
                               ̄1                    ̄1                               ̄1
       standing at 27.38 mg GAEg DW and 31.46 mg REg DW and the latter at 12.71 mg GAEg DW and 14.68
                ̄1
       mg REg DW ꎻ in the seeds of the two varietiesꎬ the contents of the free phenolics and flavonoidsꎬ which made up
       more than 79% of the total phenolics and flavonoidsꎬ were significantly higher than those of bound phenolics and fla ̄
       vonoidsꎻ the contents of bound phenolics and flavonoids were higher in the seeds of Jiujiang Kuqiao than those of
       Chuanqiao 1. (2) Rutinꎬ quercetinꎬ epicatechinꎬ kaempferolꎬ kaempferol ̄3 ̄rutinoside and quercetin ̄3 ̄O ̄rutinoside ̄
       3′ ̄O ̄glucopyranoside dominated among the phenolic compounds in the seeds of the black tartary buckwheat varietiesꎬ
       with rutin and quercetin dominant phenolics among the free phenolic compounds and epicatechin and rutin dominant
       among the bound ones. (3) All the seed extracts of the tartary buckwheat varieties presented antioxidant activities and
       the antioxidant activities of the free seed extracts of Chuanqiao 1ꎬ determining as being 30.14ꎬ 11.03 and 18.84 mg
             ̄1
       TEg DW using DPPHꎬ ABTS and FRAPꎬ respectivelyꎬ were higher than those of Jiujiang Kuqiao. The antioxidant
       activities of the bound extracts of Chuanqiao 1 were lower than those of Jiujiang Kuqiaoꎬ but the total antioxidant acti ̄
       vity of the former variety was significantly higher than that of the latter one. Thereforeꎬ planted in low ̄elevation regions
       of the Jianghan Plainꎬ Chuanqiao 1 had higher contents of seed phenolic compoundsꎬ as being required in subsequent
       food processing and presenting a bright market prospect.
       Key words: black tartary buckwheatꎬ free phenolicsꎬ bound phenolicsꎬ high performance liquid chromatography
       (HPLC)ꎬ antioxidant activity



       荞麦 分 甜 荞 ( Fagopyrum esculentum) 和 苦 荞        离酚ꎬ结合酚经过肠道微生物发酵作用后可能具
   ( F. tataricum) 两 个 栽 培 种ꎬ 集 中 分 布 在 我 国 华        有更高的生物活性ꎮ 因此ꎬ系统分析苦荞多酚的
   北、西北和西南等地区( 侯建霞ꎬ2007) ꎮ 随着人                       存在形式、结构组成对加强苦荞功能开发具有重
   们生活水平的不断提高和健康饮食观念的增强ꎬ                             要意义ꎮ
   以苦荞为原料的加工产品越来越受到消费者的                                  Klepacka et al. ( 2011) 和 邓 浩 ( 2014) 发 现ꎬ
   青睐ꎬ这主要是与其富含多种营养物质ꎬ如蛋白                             多酚类物质的含量和抗氧化活性与其品种和种
   质、维生素 和 多 酚 等 有 关 ( Zhuꎬ2016) ꎮ 植 物 多             植环境密切相关ꎮ 国旭丹等(2019) 研究表明ꎬ地
   酚是植物代谢过程中产生的一类次生物质ꎬ主要                             区环境如海拔、降水量和日照时间等会显著影响
   以游离态和结合态的形式存在于植物细胞中( 邵                            苦荞多酚的含量ꎮ Guo et al. ( 2011) 也发现生长
   雅芳ꎬ2014ꎻ颜才植等ꎬ2015) ꎮ 游离酚是可被有                      环境以及品种与环境之间相互作用可能对苦荞
   机溶剂提取的酚类物质ꎬ而结合酚是以共价键的                             多酚物质的积累和抗氧化活性产生影响ꎮ 但是
   形式与植物体相结合ꎬ不能被有机溶剂直接提取                             随着当前农业结构调整ꎬ发展绿色食品和农民增
   ( Pe′rez ̄Jime′nez & Torresꎬ2011)ꎮ 尽管已有研究报         收的需要ꎬ低海拔平原地区的小宗粮豆作物的生
   道苦荞中总酚、总黄酮的含量及其抗氧化活性( 李                           产重新引起了重视ꎮ 基于此ꎬ本研究在低海拔地
   海萍ꎬ2010ꎻ刘琴等ꎬ2014ꎻ周晓婷ꎬ2017)ꎬ但是这                    区种植川荞 1 号黑苦荞和九江苦荞两个品种ꎬ分
   些报道多集中于分析可被有机溶剂提取的游离酚                             析其籽粒中游离酚和结合酚的含量、组成及其抗
   部分ꎬ而对于结合态酚类物质的结构特征及其生                             氧化活性进行分析ꎬ旨在揭示低海拔地区黑苦荞
   物活性还很少涉及ꎮ Adom & Liu( 2002) 研 究 发                 中酚类物质存在的形式和结构特征ꎬ以期为低海
   现ꎬ玉米、小麦、大米等谷物中的酚类物质主要是                            拔平原地区生产的黑苦荞深加工和品种优化提
   以结合酚的形式存在ꎮ Liu(2007) 认为ꎬ相对于游                      供理论依据ꎮ
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