|
可食用植物不同形态酚类化合物研究进展可食用植物不同形态酚类化合物研究进展 邢 晨1,2，王俐娟1,2，王晓琴1,2,* （1.华侨大学化工学院，福建 厦门 361021；2.华侨大学 油脂及天然产物研究所，福建 厦门 361021） 摘 要：酚类化合物可预防与氧化应激有关的慢性疾病，植物是人类摄取酚类化合物的主要来源，深入研究酚类化合物对于功能性食品开发具有重要意义。近年来，研究者们发现酚类化合物以游离态和结合态存在于植物基质中，存在形态影响其在生物体内的代谢途径和活性。本文综述了植物不同形态酚类化合物的分离提取方法、在植物组织及器官中的分布、影响分布的因素以及体内外活性研究进展，以期为科学开发富含酚类化合物的功能性食品提供参考。 关键词：酚类化合物；存在形态；游离酚；结合酚；功能性食品 酚类化合物是由高等植物莽草酸、戊糖磷酸酯和苯丙烷类途径合成的次级代谢产物，在植物界中分布广泛，目前已鉴定出8 000多种结构[1]。其羟基活性基团可提供氢原子或电子，清除自由基或螯合金属离子，随后通过苯环周围未配对电子离域来稳定苯氧基，终止自由基反应[2]。酚类化合物可在体内发挥抗氧化活性，能有效降低人体患癌症、糖尿病、心血管疾病的风险[3-4]，已成为食品科学领域研究热点。由于其生物活性，富含酚类化合物的可食用植物常被视为功能性食品，且其提取物也可作为潜在的功能性成分被添加到食品中[5]。 研究酚类化合物的传统方法为采用有机溶剂直接提取后测定其含量及自由基清除能力[6-8]，忽略了不可提取的部分。不可提取部分的酚类化合物在植物中分布广泛，将其水解释放后提取，其提取物具有抗氧化活性[9]。此外，体内研究表明，不可提取部分的酚类化合物在代谢途径和生物活性方面与可提取酚相比有所不同[10-12]。本文将以可食用植物不同形态酚类化合物为综述对象，对其形态划分、提取方法、在植物组织及器官中的分布、影响分布的因素以及体内外活性四个方面进行阐述，以期为酚类化合物功能性食品开发提供参考。 1 酚类化合物在植物基质及提取物中的形态划分酚类化合物在植物中的存在形态可分为游离态（I）和结合态（II～V），游离酚是指不与其他大分子发生物理、化学相互作用的酚类化合物；结合酚按照发生相互作用方式及对象进一步细分，具体包括与大分子化学键合的结合酚（II）、与植物基质离子键合的结合酚（III）、物理截留于植物基质中的结合酚（IV）以及物理包埋于细胞结构内的结合酚（V）（表1）[13]。酚类化合物的存在形态直接影响其分离提取的难易程度[14-15]。如游离酚和物理截留于植物基质中的结合酚易溶于水或有机溶剂，可直接萃取出来；与大分子或植物基质化学键合的结合酚需要水解破坏化学键后才可提取；包埋于细胞内的结合酚需要通过水解或蒸煮等方式破坏细胞结构才可提取。酚类化合物的提取分离往往可得到多种酚提取物，为了区分它们，通常将采用有机溶剂直接萃取出的部分称为可溶性酚提取物，从剩余残渣中水解后萃取出的部分称为不溶性酚提取物。可溶性酚提取物中酚类化合物以游离态形式或与低分子化合物结合的形式存在，前者称为游离酚，后者统称为可溶性结合酚。不溶性酚提取物中酚类化合物以结合态形式存在，由于是通过水解将结合酚从不溶性残渣中释放得到的，故统称为不溶性结合酚。目前，通过分析不同形态酚提取物可以在一定程度上反映酚类化合物在植物中的存在形态，但要达到准确表征还需更多深入研究。 表 1 可食用植物酚类化合物的存在形态[13]
Table 1 Existing forms of phenolic compounds in edible plants[13]  游离酚（I）结合酚化学相互作用 物理相互作用大分子（II） 基质（III） 基质（IV） 细胞内（V）
2 植物游离酚和结合酚分离提取方法2.1 植物游离酚分离提取方法2.1.1 传统有机溶剂 采用有机溶剂进行液-液萃取是植物酚类提取的常用方法，具有易操作、高效、适用性广等特点。提取游离酚的有机溶剂包括甲醇、乙醇、丙酮、乙醚和乙酸乙酯，经常采用甲醇-水或丙酮-水[16]。一般而言，甲醇在提取低分子质量的酚类化合物时效果较好，而对于高分子质量的黄酮类化合物用丙酮-水溶液提取更高效[17-19]。另外，乙醇作为含酒精饮料的有效成分，是一种相对安全的提取溶剂，对人体产生的毒害作用较小[20]。由于提取溶剂的种类和比例会显著影响游离酚的提取率，很多学者对此进行了筛选。研究表明，采用体积分数80%的丙酮-水溶液提取荔枝果肉酚类化合物效率最高[21]，而体积分数70%的乙醇-水溶液为葡萄果渣酚类化合物提取的最佳溶剂[22]。有机溶剂提取法具有简便、高效的特点，在酚类化合物的提取方面应用广泛。然而该方法部分溶剂有毒、试剂用量较大，可能存在食品安全性问题。为了解决这个问题，近年来学者们探索新兴绿色溶剂，如低共熔溶剂（deep eutectic solvents，DES）。 2.1.2 低共熔溶剂 晞月横了青樱一眼，不欲多言。青樱亦懒得和她争辩，先扶住了富察氏，等着眼明手快的小太监抬了软轿来，一齐拥着富察氏进了偏殿。 从表3可以看出，在所采用的3种捕收剂中，当采用Z200时获得的铜品位最高，表明其选择性较好，而采用丁基黄药时对应的回收率最高，表明其捕收能力较强。综合品位和回收率两个技术指标，使用Z200和丁基黄药组合药剂有可能取得理想的技术指标，同时二者也是生产中常用的捕收剂。 DES作为一种新兴溶剂，在绿色化学、有机合成以及分离等领域具有广阔的应用前景。DES是由氢质子受体（如氯化胆碱、酰胺类化合物）与一系列氢质子供体（如氨基酸、有机酸、醇类及糖类等）按一定比例混合形成的共熔液体[23]。Dai Yuntao等[24]利用核磁共振技术探究氯化胆碱/1,2-丙二醇/水结合物的分子结构，发现氯化胆碱卤素原子与1,2-丙二醇、水的羟基形成氢键，氢键是维系DES稳定及其特殊物理特性的主要作用力。DES的物理特性类似于离子液体（蒸汽压较小、熔点低、化学性质稳定、对不同天然化合物的溶解度大），且其毒性低，并在可降解性、生物相容性方面优于离子液体，是一种理想的酚类化合物提取溶剂[25-26]。DES的提取效率受合成原料的种类及其物质的量比例影响[27-28]，对其进行筛选能有效提高酚类化合物产率。表2总结了DES法提取植物酚类化合物的应用，并列出了合成DES（提取率最高）所需的原料及其物质的量比例。相关研究表明，筛选后的DES提取效率优于有机溶剂提取法，采用氯化胆碱-木糖醇（物质的量比2∶1）和氯化胆碱-1,2-丙二醇（物质的量比1∶1）从橄榄油中提取酪醇衍生物，提取率较体积分数80%的甲醇-水溶液提取法提高了67.9%～68.3%[29]；采用氯化胆碱-乳酸（物质的量比1∶2）从黄芩中提取黄酮类化合物，提取率较体积分数60%乙醇-水溶液提取法提高了5.1%～28.1%[30]。可见，DES绿色环保、提取率高，可作为有机溶剂的潜在替代品。 表 2 DES在游离酚提取中的应用
Table 2 Applications of DES in the extraction of free phenolic compounds  基质 化合物溶剂 参考文献氢质子受体 氢质子供体 物质的量比橄榄油 酪醇、羟基酪醇、橄榄苦苷 氯化胆碱 木糖醇 2∶1 [29]橄榄油 酪醇、羟基酪醇、橄榄苦苷 氯化胆碱 1,2-丙二醇 1∶1 [29]黄芩 黄芩素、次黄芩素、次黄芩苷 氯化胆碱 乳酸 1∶2 [30]扁柏 杨梅素、穗花双黄酮 氯化胆碱 1,4-丁二醇 1∶5 [31]扁柏 杨梅素、槲皮素、穗花双黄酮 甲基三苯基溴化膦 乙二醇 1∶5 [32]红花 羟基红花色素、红花色素 L-脯氨酸 苹果酸 1∶1 [33]红花 红花苷 乳酸 葡萄糖 5∶1 [33]葡萄皮 儿茶素、花青素 氯化胆碱 乙二酸 1∶1 [34]葡萄皮 槲皮素-3-O-葡萄糖苷 氯化胆碱 丙三醇 1∶2 [34]苦荞麦壳 芦丁 氯化胆碱 丙三醇 1∶1 [35]槐花 芦丁 氯化胆碱 三甘醇 1∶4 [36]丹参 丹酚酸、迷迭香酸、紫草酸 氯化胆碱 乙酰胺 1∶1 [36]淫羊霍 淫羊霍苷 L-脯氨酸 乳酸 1∶1 [36]茶树叶 表儿茶素、表没食子儿茶素、表没食子儿茶素没食子酸酯 氯化胆碱 乳酸 1∶2 [37]绿茶 表没食子儿茶素、表没食子儿茶素没食子酸酯 氯化胆碱 乙二醇 1∶5 [38]金银花 绿原酸、咖啡酸等 氯化胆碱 1,3-丁二醇 1∶6 [39]滨蒿 咖啡酸、5-咖啡酰奎宁酸 4-甲基-氯化铵 尿素 1∶4 [40]夏枯草 迷迭香酸、异迷迭香酸苷 氯化胆碱 乙二醇 1∶4 [41]槐花 槲皮素、山柰酚、鼠李素 L-脯氨酸 葡萄糖 1∶2.5 [42]鹿蹄草 金丝桃苷、槲皮素等 氯化胆碱 1,4-丁二醇 1∶4 [43]侧扁叶 杨梅素、槲皮素、扁柏黄酮等 氯化胆碱 乙酰丙酸 1∶2 [44]木豆 芹菜素-6,8-二阿拉伯糖等 氯化胆碱 麦芽糖 1∶2 [45]木豆根 染料木苷、染料木素、芹菜素 氯化胆碱 1,6-己二醇 1∶7 [46]
2.2 结合酚分离提取方法结合态酚提取物可按其结合基质的溶解性分为可溶性结合酚和不溶性结合酚。可溶性结合酚常以共轭或酯键等化学键形式与肽、寡糖等低分子化合物结合[47-48]，这些化合物与游离酚一起被提取出来，但在色谱柱上不保留，从而无法被检测系统识别[49]；因此需要提前水解释放才可进行分析。不溶性结合酚常与细胞壁聚合物结合[47]，它们可以酯化在多糖上或通过醚键与木质素相连[50]。目前，不同存在形式结合酚的水解方法主要为碱水解和酸水解，碱水解能有效破坏酯键，酸水解能有效破坏糖苷键[51]。有研究将碱水解后萃取出的酚称为酯化[52]、共轭[53]结合酚，继续进行酸水解萃取出的酚称为醚化[54]、糖基化[55]结合酚（图1）。尽管目前没有证据揭示结合酚的成键与水解方式之间的特异性，但多种水解方式促进了结合酚的释放。可食用植物不同存在形式结合酚提取溶剂及分布情况如表3所示。结合酚水解后通常采用乙醚和乙酸乙酯萃取，然而大量有机试剂的消耗对人体和环境有害。由于水解后的结合酚化学结构与游离酚相同，DES理论上同样适用于结合酚的提取，因此可开发相关绿色环保的结合酚提取方法。目前，结合酚存在形式研究集中于酯化结合酚，这可能是因为碱水解条件较为温和，而酸水解需要在高温条件下进行，可能会使酚类化合物降解。此外，采用纤维素酶、葡聚糖酶等释放结合酚可对其存在形式进行特异性研究[56-57]；采用盐水解可表征植物基质中通过离子键合的结合酚[58]。探究结合酚存在形式有助于揭示其在植物基质中的分布规律，对相关功能性食品开发具有指导意义。 表 3 可食用植物不同存在形式结合酚提取溶剂及质量分数
Table 3 Extraction solvents and distribution of different forms of bound phenolic compounds from edible plants  注：-.文献中未检测。 参考文献黑麦粉 甲醇、丙酮、水（2∶2∶1） 乙醚、乙酸乙酯（1∶1） 乙酸乙酯 5.2～10.3 0.5～0.8 49.2～67.9 20.7～41.6 0.79～4.13 [59]花生皮 体积分数70%丙酮溶液 乙醚、乙酸乙酯（1∶1）乙醚、乙酸乙酯（1∶1） 40.2 9.3 0.8 - 160.83 [54]番荔枝 甲醇、丙酮、水（7∶7∶6） 乙醚、乙酸乙酯（1∶1）乙醚、乙酸乙酯（1∶1） 41.3 12.6 28.7 - 107.71 [55]蔓越莓豆 体积分数70%甲醇溶液 乙醚、乙酸乙酯（1∶1）乙醚、乙酸乙酯（1∶1） 28.1～86.5 - 8.8～19.9 - 0.23～0.69 [49]水果 甲醇 甲醇 甲醇 - - 0.9～7.7 4.3～9.0 3.44～11.73 [60]盐夫子 体积分数70%甲醇、体积分数70%丙酮溶液（1∶1） 乙醚、乙酸乙酯（1∶1）乙醚、乙酸乙酯（1∶1） 32.5 - 14.2 - 1 114.13 [61]毛豆 体积分数80%甲醇溶液 乙酸乙酯 乙酸乙酯 68.5～70.4 - 29.6～31.4 - 0.27～0.35 [62]果树叶 乙酸乙酯、水（1∶1） 乙酸乙酯 乙酸乙酯 11.8～26.1 - 4.5～73.5 - 9.56～136.19 [63]燕麦 体积分数80%甲醇溶液 乙酸乙酯 乙酸乙酯 41.6 - 19.2 - 2.14 [64]豆类 体积分数40%乙醇溶液、乙酸乙酯（1∶1） 乙酸乙酯 乙酸乙酯 10.8～48.3 - 9.2～43.7 - 0.81～4.02 [65]花卉 甲醇、丙酮、水（7∶7∶6） 乙酸乙酯 乙酸乙酯 3.6～24.8 - 13.2～28.0 - 12.67～165.60 [66]油籽 体积分数70%丙酮溶液 乙醚、乙酸乙酯（1∶1）乙醚、乙酸乙酯（1∶1） 58.2～70.8 - 7.0～11.2 - 11.69～22.40 [67]绢毛榄仁叶 体积分数50%乙醇溶液 乙醚、乙酸乙酯（1∶1）乙醚、乙酸乙酯（1∶1） 29.5 21.0 21.8 - 53.27 [68]沙棘果 乙醚 乙醚 乙醚 - - 21.2 58.8 1.07 [69]红枣 体积分数80%甲醇溶液 乙醚、乙酸乙酯（1∶1）乙醚、乙酸乙酯（1∶1） 18.1 33.9 40.6 - 85.21 [70]研究对象提取溶剂A（体积比）提取溶剂B（体积比）提取溶剂C（体积比）可溶酯化/共轭结合酚质量分数/%可溶醚化/糖基化结合酚质量分数/%不溶酯化结合酚质量分数/%不溶醚化/糖基化结合酚质量分数/%总酚含量/（mg/g）
 图 1 可食用植物不同存在形式结合酚提取的常用流程
Fig. 1 General extraction procedures for different forms of bound phenolic compounds from edible plants
3 游离酚和结合酚在植物组织和器官中的分布酚类化合物在植物组织内的定位反映了其对植物的生理作用[55]。植物通常将酚类化合物储存在重要部位，在那里它们充当信号或植物防御机制[71]。游离酚和结合酚的比较研究主要集中于保护组织（果皮等）和营养组织（胚芽等）（表4）。一般而言，保护组织中的总酚含量高于营养组织，可能由于保护组织起到防御不利生物（病原体、昆虫和食草动物攻击）和非生物（紫外线辐射和温度）的作用。这些植物保护组织是有价值的加工副产品，但经常作为废料被处理。此外，在小麦麸皮[72]、玉米表皮[73]和番荔枝果皮[55]中，结合酚比例很高，可作为结合酚良好的原料来源。使用含麸皮小麦粉制作的全麦面包深受广大消费者青睐，其酚类化合物含量丰富，有预防动脉粥样硬化等疾病的功效；加强对谷物外壳、果皮等废料的功能性成分研究，可实现废料资源的最大化利用。 游离酚和结合酚在植物器官中的分布研究可分为全株植物不同器官和不同植物相同器官。全株植物不同器官间的比较研究较少。续随子的根部富含游离态黄酮（1.45 mg/g），其含量高于茎部（0.03 mg/g）和种子（0.04 mg/g）[74]；绢毛榄仁果实不溶性结合酚含量（5.34 mg/g）低于根、茎、叶部位（10.38～11.62 mg/g）[68]。不同植物相同器官间的比较研究多集中于叶、花和果实，游离酚和结合酚在这些植物器官中均有分布，但由于物种特异性导致比例和含量有所差异（表4）。比较游离酚和结合酚在植物器官中的分布可全面了解富含酚类化合物的种质资源，为植物特定器官的功能性食品开发提供资料和参考。 无论是痰是瘀，调节一身之气才是化痰散瘀的关键。故祛瘀是治疗喘证的重要手段。刮痧疗法对呼吸疾病有相当的优势[10]，可加速气血运行，排出瘀毒[11]，且可调节脏腑功能[12]，使气血通畅，通达全身。《灵枢·九针十二原》：“凡用针者，虚则实之，满则泄之，菀陈则除之。”说明刺血疗法可清瘀血以达血出邪尽，血气复行的作用[13]。 表 4 游离酚和结合酚在植物不同组织和器官中的分布
Table 4 Distribution of free and bound phenolic compounds in plant tissues and organs  研究对象 结合酚质量在总酚中占比/% 总酚含量/（mg/g） 参考文献不同组织 保护组织 营养组织 保护组织 营养组织小麦 58.4～95.6 56.7～93.7 2.65～4.91 0.48～1.25 [72]玉米 93.6～95.9 95.2～96.3 57.52～91.57 1.08～2.74 [73]小米 34.5～45.8 17.9～24.0 43.01～49.06 9.21～15.87 [75]黑豆 22.4 31.6 49.00 15.50 [76]奇迹果 11.5 25.0 64.81 23.65 [77]番荔枝 93.5 92.3 53.70 34.00 [55]不同器官 营养器官 生殖器官 营养器官 生殖器官续随子 根34.4、茎36.9 种子21.4 根3.59、茎2.61 种子4.63 [74]沙棘 叶78.9 果实80.0、种子90.0 叶4.99 果实1.07、种子6.19 [69]绢毛榄仁 根71.6、茎72.9、叶72.3根53.24、茎56.01、叶53.27 [68]奇迹果 果实15.1、种子40.3果实88.46、种子19.43 [77]红枣 果实93.6、种子92.5果实85.21、种子30.95 [70]相同器官 草本植物 木本植物 草本植物 木本植物叶3 种桑树 3.0～5.2 21.66～53.14 [78]4 种蔬菜 0.05～0.08 2.81～4.41 [79]14 种果树 74.5～87.8 24.1～89.9 9.56～12.69 16.98～136.19 [63]2 种拷树 12.0～16.5 19.11～40.81 [80]花30 种花卉 22.7～60.8 23.2～44.9 15.66～101.33 12.67～165.60 [66]10 种花卉 0.2～34.4 0.7～8.5 1.09～8.47 3.38～38.77 [81]2 种向日葵 10.3～11.3 18.79～28.33 [82]12 种花卉 23.3～55.2 27.7～65.9 0.32～2.92 0.55～1.44 [83]果8 种水果 8.3 3.6～33.7 70.27 6.70～87.43 [84]11 种水果 7.7～57.1 3.8～38.1 0.90～1.60 0.50～5.27 [85]6 种水果 7.2～14.6 3.44～11.73 [60]6 种坚果 0.0～0.6 0.35～5.97 [86]10 种坚果 10.0～91.5 1.98～2.33 [87]8 种谷物 66.9～93.3 0.72～3.30 [88]
4 影响植物游离酚和结合酚分布的因素游离酚和结合酚在植物组织和器官中的分布有所不同，影响它们分布的因素众多，如原料来源、加工工艺等（表5）。来自不同产地的可食用植物，其游离酚和结合酚的分布受当地气候变化的影响，这种现象在菜豆中已有报道[89]。由于地理环境、自然杂交、人为培育等条件不同，可食用植物品种繁多，不同品种间游离酚和结合酚分布存在差异，如红色品种手指小米粥结合酚在总酚中比例（82.8%～85.0%）和总酚含量（9.47～14.50 mg/g）均比白色品种手指小米粥（61.2%～74.6%、2.13～2.55 mg/g）高[90]。在果实成熟、发芽过程中，游离酚和结合酚含量呈现多种变化趋势，表明该过程可能存在结合酚释放、聚合以及酶参与的生物化学反应[91-92]。 表 5 酚类化合物存在形态的影响因素
Table 5 Factors influencing existing forms of phenolic compounds in edible plants  影响因素 食品基质 结合酚在总酚中占比/% 总酚含量/（mg/g） 参考文献产地 菜豆Makowe（36.4）＞Mphathi（35.6）＞Chuma-Chitsala（33.4）＞Khulungira（31.2）Khulungira（2.18）＞Chuma-Chitsala（1.93）＞Mphathi（1.65）＞Makowe（1.20）[89]燕麦 99.7～99.9 Akseli最高（1.69）、Viviana最低（1.20） [97]水稻Gull Zag（10.3）＞Teli Zag（10.1）＞Kaw kareed（9.6）＞Samarkand（7.4）＞Zag（2.6）＞Shel Kew（2.2）＞Kaw Quder（1.3）Kaw Quder（13.54）＞Shel Kew（12.30）＞Zag （7.29）＞Samarkand（4.97）＞Kaw kareed（4.58）＞Teli Zag（4.14）＞Gull Zag（4.09）[98]品种小米 RV1（85.0）＞RV2（82.8）＞WV2（74.6）＞WV1（61.2）RV2（14.50）＞RV1（9.47）＞WV1（2.55）＞WV2（2.13） [90]扁豆 3494（45.3）＞Maxim（45.2）＞Invincible（43.4）＞Greenland（43.3）3494（13.08）＞Invincible（11.97）＞Greenland（11.61）＞Maxim（10.07） [99]苹果 格兰尼史密斯（56.7）＞金冠（38.0）＞红粉佳人（35.1）＞富士（29.2）金冠（1.43）＞富士（1.31）＞红粉佳人（0.91）＞格兰尼史密斯（0.41） [100]咖啡豆（成熟）成熟（8.6～18.6）、半成熟（2.5～17.5）、未成熟（5.9～54.2）成熟（2.96～6.49）、半成熟（3.20～25.54）、未成熟（1.20～10.68） [92]糙米（发芽）G2（51.1）＞G0（46.0）＞G4（44.9）＞G1（44.5）＞G3（43.6）＞G5（42.3）G5（4.38）＞G3（4.01）＞G1（3.94）＞G4（3.89）＞G2（3.85）＞G0（2.99） [91]生长过程 薏苡仁（发芽）G0（36.9）＞G1（32.3）＞G2（30.3）＞G3（26.5）＞G4（22.6）＞G5（14.6）G5（3.59）＞G4（2.96）＞G3（2.59）＞G2（2.20）＞G0（2.19）＞G1（2.19） [101]金丝雀草籽（发芽）G0（32.6）＞G1（22.8）＞G2（17.9）＞G3（9.4）＞G4（9.0）＞G5（8.5）G5（4.67）＞G4（3.31）＞G3（2.21）＞G2（1.03）＞G0（0.63）＞G1（0.56） [102]扁豆（发芽）G4（62.4）＞G1（61.3）＞G2（61.1）＞G3（59.2）＞G0（57.1）G4（16.51）＞G2（15.18）＞G3（14.33）＞G0（13.60）＝G1（13.60） [103]燕麦 发酵（62.4）＞未发酵（56.1） 发酵（2.23）＞未发酵（0.08） [64]画眉草面饼（发酵）0 h（83.7～88.0）、24 h（58.0～78.3）、72 h（74.6～81.6）、120 h（70.4～79.6）0 h（4.54～6.55）、24 h（3.64～5.84）、72 h（5.31～8.16）、120 h（4.86～7.64） [94]黑米（研磨度）不研磨（13.0～15.7）、研磨度1（13.4～15.5）、研磨度2（10.8～15.6）不研磨（7.48～10.76）、研磨度1（6.95～8.78）、研磨度2（5.07～7.55） [93]加工 黑米（烹饪方式）品种1：生米（85.3）＞烤（61.4）＞蒸（47.6）＞煎（42.5）＞煮1（42.1）＞煮2（26.6）；品种2：生米（87.9）＞煎（61.0）＞煮1（57.4）＞蒸（56.5）＞煮2（47.4）＞烤（38.2）品种1：蒸（0.29）＞煮1（0.27）＞煎（0.22）＞煮2（0.21）＞烤（0.16）＞生米（0.10）；品种2：煮1（0.45）＞煎（0.38）＞生米(0.34）＞蒸（0.33）＞煮2（0.29）＞烤（0.14）[104]面食（热处理）黑米面：生（63.2）＞熟（0.0）；鹰嘴豆面：生（64.1）＞熟（47.6）；红扁豆面：生（65.2）＞熟（21.6）；高粱面：生（62.0）＞熟（58.2）；苋菜面：生（62.3）＞熟（0.0）；藜麦面：生（61.3）＞熟（0.0）黑米面：生（51.08）＞熟（27.27）；鹰嘴豆面：生（34.13）＞熟（21.79）；红扁豆面：生（36.88）＞熟（21.15）；高粱面：生（12.22）＞熟（1.46）；苋菜面：生（29.10）＞熟（8.51）；藜麦面：生（53.27）＞熟（19.27）[95]
除上述自然因素外，食品加工、贮藏等人为因素也会对游离酚和结合酚的分布产生影响。研磨等精细加工工序会使黑米游离、结合酚含量下降[93]，可能是因为黑米保护组织（外壳、麸皮）中总酚含量比内部营养组织部分高，研磨后损失了总酚含量较高的保护组织部分。发酵过程能有效提高游离、结合酚含量，这可能是由于微生物和内源性酶作用使食品基质中的酚更容易被萃取出来，且发酵过程有机酸的产生破坏了细胞膜的通透性，促进结合酚的释放[94]。在面食加工中，烹饪等热处理工艺会使结合酚含量大幅下降，游离酚含量上升[95]，可能是因为破坏了酚与基质结合的化学键或破坏了细胞结构使结合酚释放出来。在食品贮藏过程中，游离酚含量大幅下降，而结合酚含量无显著变化[96]，可能由于与食品基质紧密结合，受氧化反应的影响较小。探究游离酚和结合酚分布的影响因素，有利于指导相关功能性食品开发，例如，通过分析植物成熟、发芽阶段酚类化合物的分布规律来选择原料进行加工；分析加工、贮藏条件来调节工艺参数，减少游离酚的损失，增加结合酚的释放；此外，还可以通过发酵等方法增加酚类化合物的含量，生产富含酚类化合物的保健食品。 今年3月，全国政协委员、中华全国供销合作总社党组成员、理事会副主任杨建平首次将中国钾盐产业发展提升到“两会”高度，引起行业关注。他建议，统筹利用国内国外两种资源，解决我国“缺钾”问题。他提出，应当加强国内钾盐资源保护性开发，加大对“境外找钾”的战略统筹和引导扶持，提升我国在国际钾肥供应中的话语权，保障我国钾肥长期稳定供应和农业战略安全。他建议，依托“一带一路”国际合作，统筹规划、有序引导中国企业“走出去”实施境外钾盐开发。 5 不同形态酚类化合物体内外生物活性酚类化合物因其具有抗氧化活性等健康特性受到广泛关注，传统研究通常采用有机溶剂直接提取后测定其总酚及自由基清除能力。大量研究表明，酚提取物的抗氧化活性与其含量显著相关[105]。近年来发现，结合酚广泛存在于植物基质中，由于无法直接萃取，通常将其水解释放后研究其提取物的抗氧化活性。与游离酚相似，结合酚的含量与抗氧化活性也显著相关，该现象已在麦片[106]、樱桃[53]、茭白[107]、水稻[72,108]和燕麦[64]等可食用植物中被报道。然而，由于基质效应等因素的影响，上述关于酚提取物的研究可能无法真实反映其在植物基质中的抗氧化表现。有学者开发了一种简单直接的抗氧化能力测定方法（QUENCHER），该方法无需水解和提取过程，直接使用分光光度法测定抗氧化能力，尤其适用于不溶性酚占比大的基质[13]。 从实验仿真结果可以看出，无论是正弦叠加的信号、含有高斯噪声的信号，还是形态有明显差别的信号，此方法都可以很好地进行信号的分解。信号分量的整体趋势不会发生变化，通过希尔伯特变换，可以计算出符合信号原始特征的瞬时频率等参数。 基于分光光度法的自由基清除能力实验很好地表征了酚类化合物体外抗氧化活性，但无法预测人体内的复杂反应[109-110]。富含酚类化合物的食品通过饮食进入人体后，酚类化合物与植物基质的结合方式会影响它们的释放和吸收[111]，进而影响其在体内的代谢途径。在植物基质中，游离酚可在小肠肠内酯酶的作用下水解，随后在肝脏或其他器官被吸收利用[112-114]；与细胞壁紧密结合的酚类化合物受小肠内酸性环境及肠内酯酶的影响较小，可到达结肠部位[115]，在结肠微生物产生的水解酶作用下缓慢持续地释放[116]，进而被肠道菌群分解为小分子进入肝肠血液循环[117]，此类结合酚具有缓慢持续释放的特点，可能会使其在体内发挥更长的抗氧化作用。研究表明，小鼠在饲喂游离态阿魏酸后，其阿魏酸血氧浓度迅速升高，4 h后消失；而给食富含结合态阿魏酸的麦麸后，在24 h内均能检测到阿魏酸血氧浓度[118]。此外，桑叶结合酚提取物能增加Ser112抗体磷酸化，进而调节过氧化物酶体增殖物激活受体γ水平，而游离酚没有表现出相关活性[119]。可见，酚类化合物存在形态影响其在体内的吸收代谢途径和抗氧化方式，结合酚在体内较为持续的抗氧化作用以及潜在的生理活性值得进一步探究。 6 结 语酚类化合物在植物中广泛地以游离态和结合态存在，不同存在形态的酚类化合物具有相似的生物活性，然而却表现出不同的生理活性。全面分析植物酚类化合物有助于科学开发其潜在的保健功效。结合当前研究状况，后续研究可从以下4 个方面加强或深入：1）结合酚分离纯化中绿色溶剂的应用，例如DES；2）谷物外壳、果皮等废料开发，这些工业废料是结合酚的良好来源，可加强相关功能性食品添加剂的开发，实现废料资源的开发利用；3）游离酚、结合酚分布影响因素的分析，可通过人为因素例如选择合适的采摘期和加工工艺，调节酚类化合物的分布；4）深入探究不同形态酚类化合物体内外生物活性，明确相关食品的潜在保健功效。 参考文献： [1] SINGH B, SINGH J P, KAUR A, et al. Phenolic composition and antioxidant potential of grain legume seeds: a review[J]. Food Research International, 2017, 101: 1-16. DOI:10.1016/j.foodres.2017.09.026. [2] SHAHIDI F, AMBIGAIPALAN P. Phenolics and polyphenolics in foods, beverages and spices: antioxidant activity and health effects: a review[J]. Journal of Functional Foods, 2015, 18: 820-897.DOI:10.1016/j.jff.2015.06.018. [3] DAI J, MUMPER R J. Plant phenolics: extraction, analysis and their antioxidant and anticancer properties[J]. Molecules, 2010, 15(10):7313-7352. DOI:10.3390/molecules15107313. [4] PEREIRA C, BARROS L, FERREIRA I C F R. Extraction,identification, fractionation and isolation of phenolic compounds in plants with hepatoprotective effects[J]. Journal of the Science of Food and Agriculture, 2016, 96(4): 1068-1084. DOI:10.1002/jsfa.7446. [5] HERRERA-CAZARES L A, HERNANDEZ-NAVARRO F,RAMIREZ-JIMENEZ A K, et al. Mango-bagasse functionalconfectionery: vehicle for enhancing bioaccessibility and permeability of phenolic compounds[J]. Food & Function, 2017, 8(11): 3906-3916.DOI:10.1039/C7FO00873B. [6] PIETTA P G. Flavonoids as antioxidants[J]. Journal of Natural Products, 2000, 63(7): 1035-1042. DOI:10.1021/np9904509. [7] KONDRATYUK T P, PEZZUTO J M. Natural product polyphenols of relevance to human health[J]. Pharmaceutical Biology, 2004, 42:46-63. DOI:10.1080/13880200490893519. [8] BRAVO L. Polyphenols: chemistry, dietary sources, metabolism, and nutritional significance[J]. Nutrition Reviews, 1998, 56: 317-333.DOI:10.1111/j.1753-4887.1998.tb01670.x. [9] SHAHIDI F, YEO J. Insoluble-bound phenolics in food[J]. Molecules,2016, 21(9): 1216. DOI:10.3390/molecules21091216. [10] ZHAO Z H, MOGHADASIAN M H. Chemistry, natural sources,dietary intake and pharmacokinetic properties of ferulic acid: a review[J]. Food Chemistry, 2008, 109(4): 691-702. DOI:10.1016/j.foodchem.2008.02.039. [11] GONZALEZ-SARRIAS A, ESPIN J C, TOMAS-BARBERAN F A.Non-extractable polyphenols produce gut microbiota metabolites that persist in circulation and show anti-inflammatory and free radicalscavenging effects[J]. Trends in Food Science & Technology, 2017,69: 281-288. DOI:10.1016/j.tifs.2017.07.010. [12] NARDINI M, NATELLA F, SCACCINI C, et al. Phenolic acids from beer are absorbed and extensively metabolized in humans[J].Journal of Nutritional Biochemistry, 2006, 17(1): 14-22. DOI:10.1016/j.jnutbio.2005.03.026. [13] GOKMEN V, SERPEN A, FOGLIANO V. Direct measurement of the total antioxidant capacity of foods: the ‘QUENCHER’ approach[J].Trends in Food Science & Technology, 2009, 20(6/7): 278-288.DOI:10.1016/j.tifs.2009.03.010. [14] PINELO M, ARNOUS A, MEYER A S. Upgrading of grape skins:significance of plant cell-wall structural components and extraction techniques for phenol release[J]. Trends in Food Science &Technology, 2006, 17(11): 579-590. DOI:10.1016/j.tifs.2006.05.003. [15] AJILA C M, BRAR S K, VERMA M, et al. Extraction and analysis of polyphenols: recent trends[J]. Critical Reviews in Biotechnology,2011, 31(3): 227-249. DOI:10.3109/07388551.2010.513677. [16] 颜才植, 叶发银, 赵国华. 食品中多酚形态的研究进展[J]. 食品科学,2015, 36(15): 249-254. DOI:10.7506/spkx1002-6630-201515046. [17] PRIOR R L, LAZARUS S A, CAO G, et al. Identification of procyanidins and anthocyanins in blueberries and cranberries(Vaccinium spp.) using high-performance liquid chromatography/mass spectrometry[J]. Journal of Agricultural and Food Chemistry, 2001,49(3): 1270-1276. DOI:10.1021/jf001211q. [18] LABARBE B, CHEYNIER V, BROSSAUD F, et al. Quantitative fractionation of grape proanthocyanidins according to their degree of polymerization[J]. Journal of Agricultural and Food Chemistry, 1999,47(7): 2719-2723. DOI:10.1021/jf990029q. [19] GUYOT S, MARNET N, DRILLEAU J. Thiolysis-HPLC characterization of apple procyanidins covering a large range of polymerization states[J]. Journal of Agricultural and Food Chemistry,2001, 49(1): 14-20. DOI:10.1021/jf000814z. [20] SHI J, NAWAZ H, POHORLY J, et al. Extraction of polyphenolics from plant material for functional foods-engineering and technology[J].Food Reviews International, 2005, 21(1): 139-166. DOI:10.1081/FRI-200040606. [21] SU D X, ZHANG R F, HOU F L, et al. Comparison of the free and bound phenolic profiles and cellular antioxidant activities of litchi pulp extracts from different solvents[J]. BMC Complementary and Alternative Medicine, 2014, 14(1): 1-10. DOI:10.1186/1472-6882-14-9. [22] SPIGNO G, TRARNELLI L, DE FAVERI D M. Effects of extraction time, temperature and solvent on concentration and antioxidant activity of grape marc phenolics[J]. Journal of Food Engineering, 2007, 81(1):200-208. DOI:10.1016/j.jfoodeng.2006.10.021. [23] CRAVEIRO R, AROSO I, FLAMMIA V, et al. Properties and thermal behavior of natural deep eutectic solvents[J]. Journal of Molecular Liquids, 2016, 215: 534-540. DOI:10.1016/j.molliq.2016.01.038. [24] DAI Yuntao, VAN SPRONSEN J, WITKAMP G J, et al. Natural deep eutectic solvents as new potential media for green technology[J].Analytica Chimica Acta, 2013, 766: 61-68. DOI:10.1016/j.aca.2012.12.019. [25] LIU Peng, HAO Jianwu, MO Liping, et al. Recent advances in the application of deep eutectic solvents as sustainable media as well as catalysts in organic reactions[J]. RSC Advances, 2015, 5(60): 48675-48704. DOI:10.1039/C5RA05746A. [26] ZHAO Bingyi, XU Pei, YANG Fuxi, et al. Biocompatible deep eutectic solvents based on choline chloride: characterization and application to the extraction of rutin from Sophora japonica[J]. ACS Sustainable Chemistry & Engineering, 2015, 3(11): 2746-2755.DOI:10.1021/acssuschemeng.5b00619. [27] FLORINDO C, OLIVEIRA F S, REBELO L P N, et al. Insights into the synthesis and properties of deep eutectic solvents based on cholinium chloride and carboxylic acids[J]. ACS Sustainable Chemistry &Engineering, 2014, 2(10): 2416-2425. DOI:10.1021/sc500439w. [28] LIU Y, GARZON J, FRIESEN J B, et al. Countercurrent assisted quantitative recovery of metabolites from plant-associated natural deep eutectic solvents[J]. Fitoterapia, 2016, 112: 30-37. DOI:10.1016/j.fitote.2016.04.019. [29] GARCIA A, RODRIGUEZ-JUAN E, RODRIGUEZ-GUTIERREZ G,et al. Extraction of phenolic compounds from virgin olive oil by deep eutectic solvents (DESs)[J]. Food Chemistry, 2016, 197: 554-561.DOI:10.1016/j.foodchem.2015.10.131. [30] WEI Zuofu, WANG Xiqing, PENG Xiao, et al. Fast and green extraction and separation of main bioactive flavonoids from Radix Scutellariae[J]. Industrial Crops and Products, 2015, 63: 175-181.DOI:10.1016/j.indcrop.2014.10.013. [31] BI Wentao, TIAN Minglei, ROW K H. Evaluation of alcoholbased deep eutectic solvent in extraction and determination of flavonoids with response surface methodology optimization[J].Journal of Chromatography A, 2013, 1285: 22-30. DOI:10.1016/j.chroma.2013.02.041. [32] TANG B, PARK H E, ROW K H. Simultaneous extraction of flavonoids from Chamaecyparis obtusa using deep eutectic solvents as additives of conventional extractions solvents[J]. Journal of Chromatographic Science,2015, 53(5): 836-840. DOI:10.1093/chromsci/bmu108. [33] DAI Yuntao, WITKAMP G J, VERPOORTE R, et al. Natural deep eutectic solvents as a new extraction media for phenolic metabolites in Carthamus tinctorius L.[J]. Analytical Chemistry, 2013, 85(13): 6272-6278. DOI:10.1021/ac400432p. [34] BUBALO M C, CURKO N, TOMASEVIC M, et al. Green extraction of grape skin phenolics by using deep eutectic solvents[J]. Food Chemistry, 2016, 200: 159-166. DOI:10.1016/j.foodchem.2016.01.040. [35] HUANG Yao, FENG Fang, JIANG Jie, et al. Green and efficient extraction of rutin from tartary buckwheat hull by using natural deep eutectic solvents[J]. Food Chemistry, 2017, 221: 1400-1405.DOI:10.1016/j.foodchem.2016.11.013. [36] DUAN Li, DOU Lili, GUO Long, et al. Comprehensive evaluation of deep eutectic solvents in extraction of bioactive natural products[J].ACS Sustainable Chemistry & Engineering, 2016, 4(4): 2405-2411.DOI:10.1021/acssuschemeng.6b00091. [37] LI Ji, HAN Zhigang, ZOU Yongpeng, et al. Efficient extraction of major catechins in Camellia sinensis leaves using green choline chloride-based deep eutectic solvents[J]. RSC Advances, 2015, 5(114):93937-93944. DOI:10.1039/c5ra15830c. [38] ZHANG H, TANG B, ROW K. Extraction of catechin compounds from green tea with a new green solvent[J]. Chemical Research in Chinese Universities, 2014, 30(1): 37-41. DOI:10.1007/s40242-014-3339-0. [39] PENG Xiao, DUAN Minghui, YAO Xiaohui, et al. Green extraction of five target phenolic acids from Lonicerae japonicae Flos with deep eutectic solvent[J]. Separation and Purification Technology, 2016,157: 249-257. DOI:10.1016/j.seppur.2015.10.065. [40] PARK H E, TANG B, ROW K H. Application of deep eutectic solvents as additives in ultrasonic extraction of two phenolic acids from Herba Artemisiae Scopariae[J]. Analytical Letters, 2014, 47(9):1476-1484. DOI:10.1080/00032719.2013.874016. [41] XIA Bohou, YAN Dong, BAI Yubing, et al. Determination of phenolic acids in Prunella vulgaris L.: a safe and green extraction method using alcohol-based deep eutectic solvents[J]. Analytical Methods, 2015,7(21): 9354-9364. DOI:10.1039/c5ay02035b. [42] NAM M W, ZHAO J, LEE M S, et al. Enhanced extraction of bioactive natural products using tailor-made deep eutectic solvents:application to flavonoid extraction from Flos sophorae[J]. Green Chemistry, 2015, 17(3): 1718-1727. DOI:10.1039/c4gc01556h. [43] YAO Xiaohui, ZHANG Dongyang, DUAN Minghui, et al. Preparation and determination of phenolic compounds from Pyrola incarnata Fisch with a green polyols based-deep eutectic solvent[J]. Separation and Purification Technology, 2015, 149: 116-123. DOI:10.1016/j.seppur.2015.03.037. [44] ZHUANG Bo, DOU Lili, LI Ping, et al. Deep eutectic solvents as green media for extraction of flavonoid glycosides and aglycones from Platycladi Cacumen[J]. Journal of Pharmaceutical and Biomedical Analysis, 2017, 134: 214-219. DOI:10.1016/j.jpba.2016.11.049. [45] WEI Zuofu, QI Xiaolin, LI Tingting, et al. Application of natural deep eutectic solvents for extraction and determination of phenolics in Cajanus cajan leaves by ultra performance liquid chromatography[J].Separation and Purification Technology, 2015, 149: 237-244.DOI:10.1016/j.seppur.2015.05.015. [46] CUI Qi, PENG Xiao, YAO Xiaohui, et al. Deep eutectic solvent-based microwave-assisted extraction of genistin, genistein and apigenin from pigeon pea roots[J]. Separation and Purification Technology, 2015,150: 63-72. DOI:10.1016/j.seppur.2015.06.026. [47] NICOLETTI I, MARTINI D, DE ROSSI A, et al. Identification and quantification of soluble free, soluble conjugated, and insoluble bound phenolic acids in durum wheat (Triticum turgidum L. var. durum) and derived products by RP-HPLC on a semimicro separation scale[J].Journal of Agricultural and Food Chemistry, 2013, 61(48): 11800-11807. DOI:10.1021/jf403568c. [48] CHEN P X, BOZZO G G, FREIXAS-COUTIN J A, et al. Free and conjugated phenolic compounds and their antioxidant activities in regular and non-darkening cranberry bean (Phaseolus vulgaris L.)seed coats[J]. Journal of Functional Foods, 2015, 18: 1047-1056.DOI:10.1016/j.jff.2014.10.032. [49] CHEN P X, TANG Y, MARCONE M F, et al. Characterization of free, conjugated and bound phenolics and lipophilic antioxidants in regular- and non-darkening cranberry beans (Phaseolus vulgaris L.)[J].Food Chemistry, 2015, 185: 298-308. DOI:10.1016/j.foodchem.2015.03.100. [50] RENGER A, STEINHART H. Ferulic acid dehydrodimers as structural elements in cereal dietary fibre[J]. European Food Research and Technology, 2000, 211(6): 422-428. DOI:10.1007/s002170000201. [51] MA Y Y, KOSINSKA-CAGNAZZO A, KERR W L, et al. Separation and characterization of soluble esterified and glycoside-bound phenolic compounds in dry-blanched peanut skins by liquid chromatographyelectrospray ionization mass spectrometry[J]. Journal of Agricultural and Food Chemistry, 2014, 62(47): 11488-11504. DOI:10.1021/jf503836n. [52] JUNG M Y, JEON B S, BOCK J Y. Free, esterified, and insolublebound phenolic acids in white and red Korean ginsengs (Panax ginseng C.A. Meyer)[J]. Food Chemistry, 2002, 79(1): 105-111.DOI:10.1016/s0308-8146(02)00185-1. [53] WANG Meng, JIANG Nan, WANG Yao, et al. Characterization of phenolic compounds from early and late ripening sweet cherries and their antioxidant and antifungal activities[J]. Journal of Agricultural and Food Chemistry, 2017, 65(26): 5413-5420. DOI:10.1021/acs.jafc.7b01409. [54] DE CAMARGO A C, REGITANO-D’ARCE M A B, SHAHIDI F.Phenolic profile of peanut by-products: antioxidant potential and inhibition of alpha-glucosidase and lipase activities[J]. Journal of the American Oil Chemists Society, 2017, 94(7): 959-971. DOI:10.1007/s11746-017-2996-9. [55] ARRUDA H S, PEREIRA G A, DE MORAIS D R, et al.Determination of free, esterified, glycosylated and insolublebound phenolics composition in the edible part of araticum fruit(Annona crassiflora Mart.) and its by-products by HPLC-ESIMS/MS[J]. Food Chemistry, 2018, 245: 738-749. DOI:10.1016/j.foodchem.2017.11.120. [56] TANG Yao, ZHANG Bing, LI Xihong, et al. Bound phenolics of quinoa seeds released by acid, alkaline, and enzymatic treatments and their antioxidant and alpha-glucosidase and pancreatic lipase inhibitory effects[J]. Journal of Agricultural and Food Chemistry, 2016, 64(8):1712-1719. DOI:10.1021/acs.jafc.5b05761. [57] ZHENG H Z, HWANG I W, CHUNG S K. Enhancing polyphenol extraction from unripe apples by carbohydrate-hydrolyzing enzymes[J]. Journal of Zhejiang University-Science B, 2009, 10(12):912-919. DOI:10.1631/jzus.B0920186. [58] MONENTE C, LUDWIG I A, IRIGOYEN A, et al. Assessment of total (ree and bound) phenolic compounds in spent coffee extracts[J].Journal of Agricultural and Food Chemistry, 2015, 63(17): 4327-4334.DOI:10.1021/acs.jafc.5b01619. [59] PIHLAVA J M, NORDLUND E, HEINIO R L, et al. Phenolic compounds in wholegrain rye and its fractions[J]. Journal of Food Composition and Analysis, 2015, 38: 89-97. DOI:10.1016/j.jfca.2014.10.004. [60] ALU’DATT M H, RABABAH T, ALHAMAD M N, et al. Profiles of free and bound phenolics extracted from citrus fruits and their roles in biological systems: content, and antioxidant, anti-diabetic and antihypertensive properties[J]. Food & Function, 2017, 8(9): 3187-3197.DOI:10.1039/C7FO00212B. [61] ZHANG Chengting, MA Yanli, GAO Fanding, et al. The free,esterified, and insoluble-bound phenolic profiles of Rhus chinensis Mill. fruits and their pancreatic lipase inhibitory activities with molecular docking analysis[J]. Journal of Functional Foods, 2018, 40:729-735. DOI:10.1016/j.jff.2017.12.019. [62] GAO Yuan, MA Shuai, WANG Meng, et al. Characterization of free,conjugated, and bound phenolic acids in seven commonly consumed vegetables[J]. Molecules, 2017, 22(11): 1878-1892. DOI:10.3390/molecules22111878. [63] CHEN Guanlin, ZHANG Xin, CHEN Songgen, et al. Antioxidant activities and contents of free, esterified and insoluble-bound phenolics in 14 subtropical fruit leaves collected from the south of China[J].Journal of Functional Foods, 2017, 30: 290-302. DOI:10.1016/j.jff.2017.01.011. [64] BEI Qi, LIU Yan, WANG Lu, et al. Improving free, conjugated, and bound phenolic fractions in fermented oats (Avena sativa L.) with Monascus anka and their antioxidant activity[J]. Journal of Functional Foods, 2017, 32: 185-194. DOI:10.1016/j.jff.2017.02.028. [65] WANG Yukun, ZHANG Xin, CHEN Guanlin, et al. Antioxidant property and their free, soluble conjugate and insoluble-bound phenolic contents in selected beans[J]. Journal of Functional Foods,2016, 24: 359-372. DOI:10.1016/j.jff.2016.04.026. [66] CHEN Guanlin, CHEN Songgen, XIAO Yi, et al. Antioxidant capacities and total phenolic contents of 30 flowers[J]. Industrial Crops and Products, 2018, 111: 430-445. DOI:10.1016/j.foodchem.2011.04.079. [67] RAHMAN M J, DE CAMARGO A C, SHAHIDI F. Phenolic profiles and antioxidant activity of defatted Camelina and sophia seeds[J]. Food Chemistry, 2018, 240: 917-925. DOI:10.1016/j.foodchem.2017.07.098. [68] ANOKWURU C, SIGIDI M, BOUKANDOU M, et al. Antioxidant activity and spectroscopic characteristics of extractable and nonextractable phenolics from Terminalia sericea Burch. ex DC[J].Molecules, 2018, 23(6): 1303. DOI:10.3390/molecules23061303. [69] ARIMBOOR R, KUMAR K S, ARUMUGHAN C. Simultaneous estimation of phenolic acids in sea buckthorn (Hippophaë rhamnoides) using RP-HPLC with DAD[J]. Journal of Pharmaceutical and Biomedical Analysis, 2008, 47(1): 31-38. DOI:10.1016/j.jpba.2007.11.045. [70] WANG B N, LIU H F, BIN ZHENG J B, et al. Distribution of phenolic acids in different tissues of jujube and their antioxidant activity[J]. Journal of Agricultural and Food Chemistry, 2011, 59(4):1288-1292. DOI:10.1021/jf103982q. [71] EWANE C A, LEPOIVRE P, DE BELLAIRE L D, et al. Involvement of phenolic compounds in the susceptibility of bananas to crown rot. a review[J]. Biotechnologie Agronomie Societe et Environnement, 2012,16(3): 393-404. DOI:10.1080/08927014.2012.723695. [72] PANG Y H, AHMED S, XU Y J, et al. Bound phenolic compounds and antioxidant properties of whole grain and bran of white, red and black rice[J]. Food Chemistry, 2018, 240: 212-221. DOI:10.1016/j.foodchem.2017.07.095. [73] DAS A K, SINGH V. Antioxidative free and bound phenolic constituents in botanical fractions of Indian specialty maize (Zea mays L.)genotypes[J]. Food Chemistry, 2016, 201: 298-306. DOI:10.1016/j.foodchem.2016.01.099. [74] ZHANG L Z, WANG C, MENG Q X, et al. Phytochemicals of Euphorbia lathyris L. and their antioxidant activities[J]. Molecules,2017, 22(8): 1335. DOI:10.3390/molecules22081335. [75] PRADEEP P M, SREERAMA Y N. Soluble and bound phenolics of two different millet genera and their milled fractions: comparative evaluation of antioxidant properties and inhibitory effects on starch hydrolysing enzyme activities[J]. Journal of Functional Foods, 2017,35: 682-693. DOI:10.1016/j.jff.2017.06.033. [76] PENG H, LI W T, LI H Y, et al. Extractable and non-extractable bound phenolic compositions and their antioxidant properties in seed coat and cotyledon of black soybean (Glycinemax (L.) merr)[J]. Journal of Functional Foods, 2017, 32: 296-312. DOI:10.1016/j.jff.2017.03.003. [77] INGLETT G E, CHEN D J. Contents of phenolics and flavonoids and antioxidant activities in skin, pulp, and seeds of miracle fruit[J].Journal of Food Science, 2011, 76(3): 479-482. DOI:10.1111/j.1750-3841.2011.02106.x. [78] ZHANG Yanxin, DU Wei, ZHANG Xuewen, et al. Antioxidant activity and the potential for cholesterol-lowering of phenolic extract of Morus alba, Morus multicaulis, and Morus laevigata leaves from Yunnan (China)[J]. Journal of Food Biochemistry, 2017, 41(1):e12339. DOI:10.1111/jfbc.12339. [79] HARBAUM B, HUBBERMANN E M, ZHU Z J, et al. Free and bound phenolic compounds in leaves of pak choi (Brassica campestris L. ssp.chinensis var. communis) and Chinese leaf mustard (Brassica juncea Coss)[J]. Food Chemistry, 2008, 110(4): 838-846. DOI:10.1016/j.foodchem.2008.02.069. [80] TUYEN P T, KHANG D T, MINH L T, et al. Phenolic compounds and antioxidant activity of Castanopsis phuthoensis and Castanopsis grandicicatricata[J]. International Letters of Natural Sciences, 2016,55: 77-87. DOI:10.18052/www.scipress.com/ILNS.55.77. [81] XIONG Lina, YANG Jiajia, JIANG Yirong, et al. Phenolic compounds and antioxidant capacities of 10 common edible flowers from China[J].Journal of Food Science, 2014, 79(4): 517-525. DOI:10.1111/1750-3841.12404. [82] LIANG Qiang, CUI Jun, LI Hang, et al. Florets of sunflower(Helianthus annuus L.): potential new sources of dietary fiber and phenolic acids[J]. Journal of Agricultural and Food Chemistry, 2013,61(14): 3435-3442. DOI:10.1021/jf400569a. [83] KAISOON O, SIRIAMORNPUN S, WEERAPREEYAKUL N, et al.Phenolic compounds and antioxidant activities of edible flowers from Thailand[J]. Journal of Functional Foods, 2011, 3(2): 88-99.DOI:10.1016/j.jff.2011.03.002. [84] OLIVAS-AGUIRRE F J, GAYTAN-MARTINEZ M, MENDOZADIAZ S O, et al. In vitro digestibility of phenolic compounds from edible fruits: could it be explained by chemometrics?[J]. International Journal of Food Science and Technology, 2017, 52(9): 2040-2048.DOI:10.1111/ijfs.13482. [85] SUN Jie, CHU Yifang, WU Xianzhong, et al. Antioxidant and antiproliferative activities of common fruits[J]. Journal of Agricultural and Food Chemistry, 2002, 50(25): 7449-7454. DOI:10.1021/jf0207530. [86] ROCCHETTI G, CHIODELLI G, GIUBERTI G, et al. Bioaccessibility of phenolic compounds following in vitro large intestine fermentation of nuts for human consumption[J]. Food Chemistry, 2018, 245:633-640. DOI:10.1016/j.foodchem.2017.10.146. [87] YANG J, LIU R H, HALIM L. Antioxidant and antiproliferative activities of common edible nut seeds[J]. LWT-Food Science and Technology, 2009, 42(1): 1-8. DOI:10.1016/j.lwt.2008.07.007. [88] IRAKLI M N, SAMANIDOU V F, BILIADERIS C G, et al.Development and validation of an HPLC-method for determination of free and bound phenolic acids in cereals after solid-phase extraction[J].Food Chemistry, 2012, 134(3): 1624-1632. DOI:10.1016/j.foodchem.2012.03.046. [89] FAN G J, BETA T. Discrimination of geographical origin of Napirira bean (Phaseolus vulgaris L.) based on phenolic profiles and antioxidant activity[J]. Journal of Food Composition and Analysis,2017, 62: 217-222. DOI:10.1016/j.jfca.2017.07.001. [90] GABAZA M, SHUMOY H, MUCHUWETI M, et al. Effect of fermentation and cooking on soluble and bound phenolic profiles of finger millet sour porridge[J]. Journal of Agricultural and Food Chemistry, 2016, 64(40): 7615-7621. DOI:10.1021/acs.jafc.6b03090. [91] TI Huihui, ZHANG Ruifen, ZHANG Mingwei, et al. Dynamic changes in the free and bound phenolic compounds and antioxidant activity of brown rice at different germination stages[J]. Food Chemistry, 2014,161: 337-344. DOI:10.1016/j.foodchem.2014.04.024. [92] RODRIGUEZ-DURAN L V, RAMIREZ-CORONEL M A,ARANDA-DELGADO E, et al. Soluble and bound hydroxycinnamates in coffee pulp (Coffea arabica) from seven cultivars at three ripening stages[J]. Journal of Agricultural and Food Chemistry, 2014, 62(31):7869-7876. DOI:10.1021/jf5014956. [93] CHOI S, SEO H S, LEE K R, et al. Effect of cultivars and milling degrees on free and bound phenolic profiles and antioxidant activity of black rice[J]. Applied Biological Chemistry, 2018, 61(1): 49-60.DOI:10.1007/s13765-017-0335-3. [94] SHUMOY H, GABAZA M, VANDEVELDE J, et al. Soluble and bound phenolic contents and antioxidant capacity of tef injera as affected by traditional fermentation[J]. Journal of Food Composition and Analysis, 2017, 58: 52-59. DOI:10.1016/j.jfca.2017.01.004. [95] ROCCHETTI G, LUCINI L, CHIODELLI G, et al. Impact of boiling on free and bound phenolic profile and antioxidant activity of commercial gluten-free pasta[J]. Food Research International, 2017,100: 69-77. DOI:10.1016/j.foodres.2017.08.031. [96] ZIEGLER V, FERREIRA C D, HOFFMANN J F, et al. Cooking quality properties and free and bound phenolics content of brown,black, and red rice grains stored at different temperatures for six months[J]. Food Chemistry, 2018, 242: 427-434. DOI:10.1016/j.foodchem.2017.09.077. [97] MULTARI S, PIHLAVA J M, OLLENNU-CHUASAM P, et al.Identification and quantification of zvenanthramides and free and bound phenolic acids in eight cultivars of husked oat (Avena sativa L)from Finland[J]. Journal of Agricultural and Food Chemistry, 2018,66(11): 2900-2908. DOI:10.1021/acs.jafc.7b05726. [98] BHAT F M, RIAR C S. Characterizing the pigmented traditional rice cultivars grown in temperate regions of Kashmir (India) for free and bound phenolics compounds and in vitro antioxidant properties[J].Journal of Cereal Science, 2017, 76: 253-262. DOI:10.1016/j.jcs.2017.06.018. [99] YEO J, SHAHIDI F. Effect of hydrothermal processing on changes of insoluble-bound phenolics of lentils[J]. Journal of Functional Foods,2017, 38: 716-722. DOI:10.1016/j.jff.2016.12.010. [100] LEE J, CHAN B L S, MITCHELL A E. Identification/quantification of free and bound phenolic acids in peel and pulp of apples(Malus domestica) using high resolution mass spectrometry(HRMS)[J]. Food Chemistry, 2017, 215: 301-310. DOI:10.1016/j.foodchem.2016.07.166. [101] XU L, WANG P, ALI B, et al. Changes of the phenolic compounds and antioxidant activities in germinated adlay seeds[J]. Journal of the Science of Food and Agriculture, 2017, 97(12): 4227-4234.DOI:10.1002/jsfa.8298. [102] CHEN Zhijie, YU Lilei, WANG Xinkun, et al. Changes of phenolic profiles and antioxidant activity in canaryseed (Phalaris canariensis L.)during germination[J]. Food Chemistry, 2016, 194: 608-618.DOI:10.1016/j.foodchem.2015.08.060. [103] YEO J D, SHAHIDI F. Critical evaluation of changes in the ratio of insoluble bound to soluble phenolics on antioxidant activity of lentils during germination[J]. Journal of Agricultural and Food Chemistry,2015, 63(2): 379-381. DOI:10.1021/jf505632p. [104] RYU D, KOH E. Influence of cooking methods on free and bound phenolic acids in Korean black rice[J]. Journal of Food Processing and Preservation, 2017, 41(2): 1-8. DOI:10.1111/jfpp.12873. [105] FERNANDEZ-PANCHON M S, VILLANO D, TRONCOSO A M, et al.Antioxidant activity of phenolic compounds: from in vitro results to in vivo evidence[J]. Critical Reviews in Food Science and Nutrition,2008, 48(7): 649-671. DOI:10.1080/10408390701761845. [106] SUMCZYNSKI D, KOUBOVA E, SNEYD J, et al. Preparation of non-traditional Dickkopf and Richard wheat flakes: phenolic and vitamin profiles and antioxidant activity[J]. LWT-Food Science and Technology, 2018, 90: 31-37. DOI:10.1016/j.lwt.2017.12.004. [107] SUMCZYNSKI D, KOTASKOVA E, ORSAVOVA J, et al.Contribution of individual phenolics to antioxidant activity and in vitro digestibility of wild rices (Zizania aquatica L.)[J]. Food Chemistry,2017, 218: 107-115. DOI:10.1016/j.foodchem.2016.09.060. [108] SHAO Yafang, HU Zhangqiang, YU Yonghong, et al. Phenolic acids, anthocyanins, proanthocyanidins, antioxidant activity,minerals and their correlations in non-pigmented, red, and black rice[J]. Food Chemistry, 2018, 239: 733-741. DOI:10.1016/j.foodchem.2017.07.009. [109] GRANATO D, SHAHIDI F, WROLSTAD R, et al. Antioxidant activity, total phenolics and flavonoids contents: Should we ban in vitro screening methods?[J]. Food Chemistry, 2018, 264: 471-475.DOI:10.1016/j.foodchem.2018.04.012. [110] HARNLY J. Antioxidant methods[J]. Journal of Food Composition and Analysis, 2017, 64: 145-146. DOI:10.1016/j.jfca.2017.08.011. [111] PALAFOX-CARLOS H, AYALA-ZAVALA J F, GONZALEZAGUILAR G A. The role of dietary fiber in the bioaccessibility and bioavailability of fruit and vegetable antioxidants[J]. Journal of Food Science, 2011, 76(1): R6-R15. DOI:10.1111/j.1750-3841.2010.01957.x. [112] CROZIER A, CLIFFORD M N, ASHIHARA H. Chapter 8.Absorption and metabolism of dietary plant secondary metabolites[M].Plant secondary metabolites: occurrence, structure and role in the human diet. Oxford: Blackwell Publishing Ltd, 2007: 303-351.DOI:10.1002/9780470988558.ch8. [113] HOLE A S, RUD I, GRIMMER S, et al. Improved bioavailability of dietary phenolic acids in whole grain barley and oat groat following fermentation with probiotic Lactobacillus acidophilus, Lactobacillus johnsonii, and Lactobacillus reuteri[J]. Journal of Agricultural and Food Chemistry, 2012, 60(25): 6369-6375. DOI:10.1021/jf300410h. [114] MANACH C, WILLIAMSON G, MORAND C, et al. Bioavailability and bioefficacy of polyphenols in humans. I. review of 97 bioavailability studies[J]. American Journal of Clinical Nutrition,2005, 81(1): 230S-242S. DOI:10.1021/jo070579k. [115] PEREZ-JIMENEZ J, DIAZ-RUBIO M E, SAURA-CALIXTO F.Non-extractable polyphenols, a major dietary antioxidant: occurrence,metabolic fate and health effects[J]. Nutrition Research Reviews,2013, 26(2): 118-129. DOI:10.1017/S0954422413000097. [116] KROON P A, FAULDS C B, RYDEN P, et al. Release of covalently bound ferulic acid from fiber in the human colon[J]. Journal of Agricultural and Food Chemistry, 1997, 45: 661-667. DOI:10.1021/jf9604403. [117] URPI-SARDA M, MONAGAS M, KHAN N, et al. Targeted metabolic profiling of phenolics in urine and plasma after regular consumption of cocoa by liquid chromatography-tandem mass spectrometry[J]. Journal of Chromatography A, 2009, 1216(43): 7258-7267. DOI:10.1016/j.chroma.2009.07.058. [118] RONDINI L, PEYRAT-MAILLARD M N, MARSSET-BAGLIERI A,et al. Bound ferulic acid from bran is more bioavailable than the free compound in rat[J]. Journal of Agricultural and Food Chemistry, 2004,52(13): 4338-4343. DOI:10.1016/S0007-8506(07)60629-5. [119] GURUKAR M S A, CHILKUNDA N D. Morus alba leaf bioactives modulate peroxisome proliferator activated receptor gamma in the kidney of diabetic rat and impart beneficial effect[J]. Journal of Agricultural and Food Chemistry, 2018, 66(30): 7923-7934.DOI:10.1021/acs.jafc.8b01357.
Recent Studies on Free and Bound Phenolic Compounds in Edible Plants: A Review XING Chen1,2, WANG Lijuan1,2, WANG Xiaoqin1,2,*
(1. College of Chemical Engineering, Huaqiao University, Xiamen 361021, China;2. Institute of Oil and Natural Product, Huaqiao University, Xiamen 361021, China) Abstract: Phenolic compounds have function to prevent chronic diseases related to oxidative stress. Plants are the main source of phenolic compounds for humans, and in-depth exploration of phenolic compounds is of great significance for the development of functional foods. In recent years, increasing studies have demonstrated that phenolic compounds are present in plant matrices in free and bound forms, which affect their in vivo metabolic pathways and biological activities. In this review, the methods used for the separation and extraction of free and bound phenolic compounds, their distribution in plant tissues and organs and in vitro and in vivo activities, and the factors affecting their distribution are summarized, which will provide valuable information for scientific development of functional foods rich in phenolic compounds. Keywords: phenolic compounds; existing form; free phenolics; bound phenolics; functional foods
收稿日期：2018-12-12 基金项目：国家自然科学基金青年科学基金项目（31601403）；福建省科技计划高校产学合作项目（2017N51010055）；厦门市科技计划项目（3502220161230）；华侨大学中青年教师科研提升资助计划项目（ZQN-PY417）；华侨大学研究生科研创新基金资助项目 DOI:10.7506/spkx1002-6630-20181212-154 中图分类号：TS225.1 文献标志码：A 文章编号：1002-6630（2020）05-0266-10 引文格式： 邢晨, 王俐娟, 王晓琴. 可食用植物不同形态酚类化合物研究进展[J]. 食品科学, 2020, 41(5): 266-275. DOI:10.7506/spkx1002-6630-20181212-154. http://www.spkx.net.cnXING Chen, WANG Lijuan, WANG Xiaoqin. Recent studies on free and bound phenolic compounds in edible plants: a review[J]. Food Science, 2020, 41(5): 266-275. (in Chinese with English abstract) DOI:10.7506/spkx1002-6630-20181212-154. http://www.spkx.net.cn
| 
|Archiver|手机版|小黑屋|www.openhelp100.com
( 冀ICP备19026749号-1 )
发表于 2021-2-1 21:05:02
