微波处理对胡柚皮酚酸、黄烷酮糖苷含量及抗氧化性的影响

目的研究微波处理对胡柚皮中酚酸、黄烷酮糖苷含量及其抗氧化能力的影响.方法高效液相结合紫外-可见光二极管阵列检测器测定胡柚皮中7种主要酚酸和4种黄烷酮糖苷含量;分别采用福林酚法、ABTS法和FRAP法对胡柚皮提取液的抗氧化能力进行评价.结果微波处理后,游离酚酸部分增加(P＜0.05),但总酚酸含量减少(P＜0.05),且总黄烷酮糖苷含量也有所减少(P＜0.05);微波处理可以提高其抗氧化能力(P＜0.05).其原因是自由酚酸部分增加;黄烷酮糖苷分解为对应的抗氧化能力更强的黄烷酮糖苷配基.结论微波处理可以显著提高胡柚皮的抗氧化能力.     

柑橘果皮中类黄酮组成与抗氧化能力研究

采用高效液相色谱测定了15个柑橘品种果皮中的6种主要类黄酮的含量,并用4种抗氧化方法(DPPH法、FRAP法、金属螯合能力法、TBARS法)对其提取液的抗氧化能力进行分析。结果显示,椪柑果皮中多甲氧基黄酮含量最高(川陈皮素为9.01 mg/g DW,橘皮素为5.10 mg/g DW),普通温州蜜桔果皮具有最高含量的柚皮芸香柑(10.83 mg/g DW)、橙皮苷(56.74 mg/g DW)与总黄酮(六种类黄酮之和为68.26 mg/g DW)。大部分柑橘品种的果皮提取液有较强的抗氧化能力,FARP法与DPPH法的测定结果相关性显著(p0.05),而与金属螯合能力法、TBARS法测定结果相关性不显著(p0.05)。     

不同品种柑橘果皮中类黄酮含量及其采后变化

为研究不同品种柑橘果皮中6 种主要类黄酮化合物的分布及含量,以及果皮采后类黄酮含量的变化。通过快速液相色谱法测定宫川温州蜜柑、衢州椪柑、哈姆林甜橙、常山胡柚和蕉柑果皮中橙皮苷、柚皮苷、新橙皮苷、川皮素、橙黄酮、橘皮素的含量以及椪柑果实采后不同时期果皮中总黄酮含量。结果表明：5 种柑橘果皮中,常山胡柚果皮中6 种总黄酮总量最高,其主要类黄酮成分为柚皮苷和新橙皮柑;宫川温州蜜柑和哈姆林甜橙果皮中主要为橙皮苷;衢州椪柑和蕉柑果皮中则主要为橙皮苷和川皮素;衢州椪柑采后随着果皮中叶绿素的降低和类胡萝卜素含量的增加,果皮中总黄酮含量前期呈上升趋势,至15d 后有所降低。     

不同成熟期蜜桔中酚酸的组成与分布

酚酸具有多种生理功能,在植物中广泛存在.柑橘可能是膳食酚酸的重要来源.采用HPLC-PDA测定了不同成熟期温州蜜桔中八种酚酸的含量,即绿原酸、咖啡酸、对香豆酸、阿魏酸、芥子酸、原儿茶酸、对羟基苯甲酸和香草酸.结果显示,果肉中酚酸含量随成熟度提高而减少,果皮酚酸含量在半成熟期最高;果皮中酚酸含量大大高于果肉;果皮果肉中都以肉桂酸型酚酸为主,苯甲酸型酚酸含量较少;蜜桔果实中绿原酸和阿魏酸是所测八种酚酸中含量最高的.对柑橘中酚酸组成与分布的研究可望应用于食品营养标识、柑橘品种的识别或加工果汗掺假的识别等.     

不同晚熟柑橘中酚类物质的含量检测及分析

采用超高效液相色谱(ultra-performance liquid chromatography,UPLC)对9种晚熟柑橘(沃柑、春见、大雅柑、不知火、默科特、红肉脐橙、伦晚脐橙、红翠2号和塔罗科血橙)中的主要酚类物质(13种类黄酮和7种酚酸)进行测定,分析比较不同品种柑橘果皮、果肉和果汁(柑橘原汁)中酚类物质种类和含量的差异。结果表明:9个柑橘品种的果皮、果肉、果汁中,类黄酮均以橙皮苷为主,酚酸以阿魏酸为主,且果皮中多甲氧基黄酮含量丰富。在9个柑橘品种果汁中,春见的橙皮苷、咖啡酸含量最高。果肉中,沃柑中阿魏酸、咖啡酸、芥子酸含量最高,塔罗科血橙的橙皮苷、对香豆酸含量最高。果皮中,默科特的芸香柚皮苷、川皮苷、阿魏酸含量最高。杂柑果皮中咖啡酸、阿魏酸及川皮苷含量高于橙类。晚熟柑橘含有丰富的酚类物质,并呈现显著的多样性。     

23个柑橘品种果实油胞层类黄酮组分鉴定与抗氧化活性研究

选取23个柑橘品种果实油胞层,采用高分辨质谱等技术鉴定其主要类黄酮组分,研究其抗氧化活性。结果表明:柑橘果实油胞层的总酚含量在4.38～21.10 mg GAE/g DW之间。柑橘果实油胞层综合抗氧化能力最强,最弱的品种分别为“本地早”“爱媛38”。从23种柑橘果实油胞层中共鉴定出53种类黄酮,包括5种黄酮-C-糖苷,4种黄酮-O-糖苷,12种黄烷酮-O-糖苷,32种多甲氧基黄酮(PMFs),有2种类黄酮为首次在柑橘中被鉴定出,分别是根皮素-3’,5’-二-C-葡萄糖苷和槲皮-3-O-鼠李糖基己糖苷。油胞层中的黄烷酮类化合物主要为圣草次苷、新圣草次苷、柚皮芸香苷、橙皮苷和香蜂草苷,PMFs主要为川陈皮素、橘皮素、5HPMF和甜橙黄酮。本文进一步挖掘并补充不同柑橘品种组分和抗氧化活性信息,为活性研究提供理论依据,也为消费提供科学指导。     

4种柠檬不同组织的酚类物质分布及其抗氧化特性

采用分光光度计法评价4种柠檬(尤力克黄柠檬、小青柠、青柠檬、香水柠檬)中果皮与果肉的总酚含量与抗氧化活性(清除ABTS+自由基能力、铁离子还原能力和清除DPPH自由基能力),并用超高效液相色谱对其酚类物质进行定性和定量。结果表明:4种柠檬果皮中的总酚含量及抗氧化活性均显著高于果肉(P0.05),其中尤力克果皮与果肉的总酚、抗氧化活性均显著高于其余3个品种(P0.05),而香水柠檬果皮与果肉中总酚、清除ABTS+自由基能力均最低。不同品种柠檬中酚酸、类黄酮种类及含量差异较大。从4种柠檬中共检出21种酚类物质,其中酚酸6种,黄酮6种,黄烷酮6种,多甲氧基黄酮3种。柠檬中的酚类物质主要是黄烷酮,占类黄酮总量61.82%～91.61%,其中青柠檬果皮中酚酸总量最高(535.62 mg/100 g DW),尤力克果皮中类黄酮总量最高(1 506.33 mg/100 g DW),果肉规律与果皮基本一致,然而其含量显著低于果皮含量(P0.05)。从尤力克果皮与果肉中共检出15种酚类物质,其中圣草枸橼含量最高,而新绿原酸是含量最高的酚酸。从小青柠、青柠檬和香水柠檬的果皮与果肉中分别检测出19,16,15种酚类物质,其中橙皮苷含量均最高,而香草酸是含量最高的酚酸。不同品种柠檬的总酚和总类黄酮含量与ABTS+呈极显著的正相关性,同时总酚含量与DPPH呈显著性的正相关性。     

超声波辅助法提取广西柑橘皮中橙皮苷

目的:对超声波辅助法提取广西柑橘皮中橙皮苷的工艺条件进行优化。方法:通过单因素和正交试验法对超声波辅助碱提酸沉工艺条件进行考察,紫外分光光度法测定柑橘皮中橙皮苷含量。结果:超声波辅助法提取柑橘皮中橙皮苷的最佳工艺:pH13料液比1:10碱液提取,超声功率40W,超声时间40min/次,超声次数2次,提取液调节pH为4,沉淀8h,橙皮苷含量最高为4.00%(n=6)。结论:超声波辅助提取橙皮苷最优工艺稳定可行。     

温州蜜柑、椪柑采后酚类物质及抗氧化活性比较研究

通过研究温州蜜蜂柑、椪柑两个常见柑橘品种贮藏期间类黄酮、酚酸类物质及抗氧化活性的变化规律,评价其采后的营养品质。结果表明：贮藏60d后温州蜜柑较好地保持了抗坏血酸含量,而椪柑损失较大。类黄酮类物质较稳定,温州蜜柑中黄烷酮含量贮藏后有所增加,椪柑中则呈缓慢下降趋势,2种柑橘中酚酸类物质贮藏后都有所增加。总酚含量在贮藏前期呈下降趋势,贮藏后期温州蜜柑中总酚含量增加而在椪柑中进一步下降。抗氧化能力与抗坏血酸的变化趋势类似。与椪柑相比,贮藏期间温州蜜柑能更好地保持果实的营养品质及酚类物质,从而保持较高的抗氧化活性。     

15种柑橘果皮中酚酸的含量测定

采用反相液相色谱法(RP-HPLC)测定了15种柑橘果皮中7种酚酸的含量,并用数学统计的方法分析了各种酚酸含量和总酚酸含量的差异性,旨在寻找酚酸提取的新来源,为柑檑资源的合理开发利用和抗氧化活性的研究提供参考。结果表明:酚酸在柑橘果皮中主要以可溶性酚酸形式存在,且肉桂酸类酚酸的含量要高于苯甲酸类酚酸的含量。在可溶性酚酸中,阿魏酸和芥子酸是柑橘果皮中最主要的酚酸;而不可溶性酚酸则以阿魏酸含量最高,原儿茶酸含量最低。对于总的酚酸含量而言,朱红果皮柑橘含量最高为6857.88μg/g(干重);胡柚果皮中最低,仅为549.62μg/g(干重)。     

Minerals, phenolic compounds, and antioxidant capacity of citrus peel extract by hot water

ABSTRACT:  Some dried citrus peels, more familiar as chenpi in China, have been widely used in traditional Chinese medicines from ancient times. This paper reports the efficiency of infusion cooking on extracting minerals and phenolic compounds (flavanone glycosides [FGs], polymethoxylated flavones [PMFs], and phenolic acids), and also antioxidant activity of hot water extract of citrus peels. Peels of 2 citrus varieties, namely, Satsuma mandarin ( C. unshiu Marc.) and Ponkan ( C. poonensis Hort. ex Tanaka), which belong to C. reticulata , were selected. As a result, hot water extraction was efficient in extracting phenolic acids and some minerals. As for citrus flavonoids, narirutin, nobiletin, and tangeretin were easier to extract than hesperidin. The result of antioxidant capacity assays indicated that for citrus peels, hot water extract had almost the same capacity as the methanol extract. We suggested that Ponkan was more suitable as the source of chenpi , since its hot water extract had much higher content of phenolic acids, FGs and PMFs, and higher antioxidant capacity than those of Satsuma mandarin. Generally, to raise the extraction temperature or to prolong the time could not yield higher content of phenolic compounds and stronger antioxidant capacity, though the content of minerals increased to some extent. Furthermore, a 2nd-time extraction seemed necessary since considerable minerals and phenolic compounds could be obtained by doing so. Finally, we suggested that 2 times extraction at 100 °C for 30 min was proper to extract the minerals and phenolic compounds in chenpi .     

Changes in the phenolic contents and antioxidant activities of citrus peels from different cultivars after in vitro digestion

The aim of this study was to investigate the effects of in vitro digestion on the phenolic contents and antioxidant activities of citrus peels. Three different varieties of citrus peels (mandarin, ponkan and red tangerine) were treated with simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). The results showed that the SGF or SIF treatments of the citrus peels did not significantly increase the total phenolic content (TPC) or total flavonoid content (TFC), except for that of the TFC of ponkan peel treated with SGF. However, simulated in vitro digestion did improve the antioxidant activities measured with FRAP and ABTS methods. The effect of SGF was more positive than those of SIF for the FRAP assay, but the opposite was true for ABTS. Notably, both simulated digestion techniques decreased the DPPH free radical scavenging abilities. Simulated digestion in vitro changed the antioxidant activities of the citrus peels.     

Effect of microwave treatment on phenolic content and antioxidant activity of citrus mandarin pomace

The effects of microwave treatment on the phenolic compounds and antioxidant capacity of citrus mandarin pomace were evaluated. After treatment, methanol extracts of citrus pomace were prepared and the contents of phenolic acids (free and bound) and flavanol, flavanone and flavonol compounds (FCs) were determined by HPLC. Antioxidant capacity of pomace extracts was measured using DPPH radical-scavenging assay, hydroxyl radical-scavenging assay and reducing power. After microwave treatment, the free fraction of phenolic acids increased, whereas the bound fractions decreased and antioxidant activity was increased. The content of total FCs increased with power but, at longer irradiation time, it declined which meant that some FCs might be degraded. The results indicated that appropriate microwave treatment could be an efficient process to liberate and activate the bound phenolic compounds and to enhance the antioxidant activity of citrus mandarin pomace.     

热水提取胡柚果皮中矿物质、酚类物质及其水提液抗氧化性研究

目的:研究热水提取胡柚果皮矿物质、酚类物质的效率及其提取液的抗氧化能力.方法:原子吸收光谱法测定七种主要矿物质;高效液相法测定胡柚皮中七种主要酚酸和六种黄酮;福林酚法、FRAP、DPPH法测定提取液的抗氧化能力.结果:热水提取可以有效提取胡柚果皮中的酚类物质与部分矿物质.抗氧化能力分析表明,热水提取液具有与甲醇提取液相近的抗氧化能力.结论:传统中药煎煮条件(100℃,30min)可以有效提取柑橘类中药的酚类物质与部分矿物质.     

COMPOSITION OF MAJOR FLAVANONE GLYCOSIDES AND ANTIOXIDANT CAPACITY OF THREE CITRUS VARIETIES

This paper reported on the composition of major flavanone glycosides (FGs) and antioxidant capacity of three Chinese citrus varieties during maturity, namely, Ponkan (P; citrus poonensis Hort. ex Tanaka), Satsuma mandarin (S; citrus unshiu Marc.) and Huyou (H; citrus paradisi Macf. cv. Changshanhuyou). The results showed that citrus peel is a rich source of FGs. Total penolics contents (TPC) of methanol extract of P, S and H were determined. The total antioxidant capacity (TAC) of P, S and H extracts was compared based on vitamin C equivalent antioxidant capacity by 2, 2-diphenyl-1-picrylhydrazyl radical (DPPH·), 2, 2 ' -azinobis (3-ethylbenzothiazoline-6-sulfonate) (ABTS ^·+ ), reducing power and ferric reducing antioxidant power (FRAP) assay. Phenolic compounds may contribute a lot to TAC of fresh fruits, especially for unripe fruits. The correlations among TPC, DPPH·, ABTS ^·+ , reducing power and FRAP assay were rather high ( P <  0.05).

PRACTICAL APPLICATION

Citrus flavonoids are abundant in citrus fruits, especially FGs, such as hesperidin and naringin; and they are attracting more attentions for their biological properties and health benefits. The sun-dried citrus peels ( chenpi ) are usually used in the traditional Chinese medicine for high content of hesperidin. Investigation on the composition of FGs in peel and edible part of citrus fruits during maturity is necessary to establish a database for the future use in health foods and ingredients. Meanwhile, four methods were employed simultaneously to achieve a comprehensive evaluation on the antioxidant capacity of the three citrus varieties. The high antioxidant potential of the three selected citrus varieties made them desirable for dietary prevention of cardiovascular and other diseases.     

Juice components and antioxidant capacity of citrus varieties cultivated in China

Juices from fifteen citrus varieties (seven mandarins, four sweet oranges, one lemon, one grapefruit, and two pummeloes) of China were investigated mainly on quality parameters, total carotenoid, phenolic compounds (total phenolics, flavanone glycosides (FGs), and phenolic acids), and antioxidant capacity (ferric reducing antioxidant power (FRAP) assay and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay). Among the fifteen varieties, Bendizao had the highest content of total carotenoid (10.02 mg/L), Satsuma had the highest content of narirutin (288.12 mg/L), Yinzaocheng had the highest content of hesperidin (533.64 mg/L), and Huyou had the highest content of naringin (348.53 mg/L), neohesperidin (265.25 mg/L) and total FGs (746.08 mg/L). As for total phenolic acids, Liubencheng had the highest content (72.61 mg/L). Hybrid 439 achieved the highest AA content (631.25 mg/L), and the highest total phenolics (1555.49 mg/L) and the greatest inhibition of DPPH radical (61.62%). Hamlin had the highest ascorbic acid equivalent antioxidant capacity (AEAC: 899.31 mg/L) determined by FRAP assay. Correlation coefficients of AA, total phenolics (gallic acid equivalent), FRAP (AEAC), DPPH (I%), total FGs and total phenolic acids indicated that AA played a major role for the antioxidant capacity of citrus juices, and phenolics also played an important role, which may be mainly ascribed to FGs, whilst phenolic acids seemed to play a minimal role. Furthermore, Huyou and Hybrid 439 were considered two valuable varieties from the view of antioxidant capacity and nutrition.