花生红衣多酚的研究进展

花生红衣中含有丰富的活性物质,具有很高的营养和利用价值,但在我国作为花生产业副产品的红衣利用率并不高。近年来,其生物活性日益受到人们关注。多酚物质是花生红衣中一种天然大分子化合物,根据对近年来国内外相关资料文献的统计分析,从提取、纯化和生物活性等方面对其研究现状作了介绍,并展望了其应用前景。     

Chemical,biochemical, and biological significance of polyphenols in cereals and legumes

Polyphenols in cereals and legumes have been receiving considerable attention largely because of their adverse influence on color, flavor, and nutritional quality. These compounds belong to the flavonoid and tannin groups and are mostly located in the seed coat or pericarp of the grains. The pearl millet flavonoids have been identified as C‐glycosylflavones by the combined use of paper chromatography and UV spectroscopy. Although nontoxic, physiological and nutritional significance of these compounds occurring in high amounts in the pearl millet grain are still not clearly understood. In view of aesthetic quality, bleaching of the millet grains in acidic solution is recommended. A large proportion of current assays involves spectrophotometry of tannin or its chromogen and tannin‐protein interaction. Sorghum and legume tannins have been characterized as condensed tannins. Several factors such as plant type, age of the plant or plant parts, stage of development, and environmental conditions govern the polyphenol contents in plants. Polyphenols are known to interact with proteins and form tannin‐protein complexes leading to either inactivation of enzymes or making proteins insoluble. These are implicated in decreasing the activities of digestive enzymes, protein and amino acid availabilities, mineral uptake, vitamin metabolism, and depression of growth. Polyphenols are known to cause certain ultrastructural changes in the different parts of experimental animals. A correlation between dietary tannins and occurrence of esophageal cancer has been established. Bird resistance and seed germination in food crops have been correlated to high contents of polyphenols. The antinutritional activity of polyphenols can be reduced by removing polyphenols from the grains by chemical treatments or removing pericarp and testa by pearling. Treatment of alkaline reagents and ammonia can remove 90% of the polyphenols. Supplementation of polyphenols‐rich diet with protein can alleviate the growth‐depressing effect of polyphenols.     

Chemical, biochemical, and biological significance of polyphenols in cereals and legumes

Polyphenols in cereals and legumes have been receiving considerable attention largely because of their adverse influence on color, flavor, and nutritional quality. These compounds belong to the flavonoid and tannin groups and are mostly located in the seed coat or pericarp of the grains. The pearl millet flavonoids have been identified as C-glycosylflavones by the combined use of paper chromatography and UV spectroscopy. Although nontoxic, physiological and nutritional significance of these compounds occurring in high amounts in the pearl millet grain are still not clearly understood. In view of aesthetic quality, bleaching of the millet grains in acidic solution is recommended. A large proportion of current assays involves spectrophotometry of tannin or its chromogen and tannin-protein interaction. Sorghum and legume tannins have been characterized as condensed tannins. Several factors such as plant type, age of the plant or plant parts, stage of development, and environmental conditions govern the polyphenol contents in plants. Polyphenols are known to interact with proteins and form tannin-protein complexes leading to either inactivation of enzymes or making proteins insoluble. These are implicated in decreasing the activities of digestive enzymes, protein and amino acid availabilities, mineral uptake, vitamin metabolism, and depression of growth. Polyphenols are known to cause certain ultrastructural changes in the different parts of experimental animals. A correlation between dietary tannins and occurrence of esophageal cancer has been established. Bird resistance and seed germination in food crops have been correlated to high contents of polyphenols. The antinutritional activity of polyphenols can be reduced by removing polyphenols from the grains by chemical treatments or removing pericarp and testa by pearling. Treatment of alkaline reagents and ammonia can remove 90% of the polyphenols. Supplementation of polyphenols-rich diet with protein can alleviate the growth-depressing effect of polyphenols.     

Changes in polyphenols of sapota fruit (Achras zapota L.) during maturation

The changes in polyphenols of sapota fruit during maturation have been determined by chemical analysis, paper chromatography and taste evaluation. Simple polyphenols are shown to decrease while polymeric leucoanthocyanidins increase with maturation. The reduction in astringency as the fruit develops has been found to be due to polymeric changes, the influence of other constituents such as sugar, and ‘dilution’ of polyphenols by increase in fruit size.     

花生红衣中多酚的研究进展

多酚作为一种生物活性成分,对它的分离提取、结构和功能的研究由来已久。文中对花生红农多酚的测定方法、提取、分离纯化,以及抗氧化和抑菌活性等做了论述。     

多酚对核桃仁食用品质影响的初步研究

本文分析了不同品种核桃仁中多酚对其食用品质的影响。研究结果表明,核桃仁的口感品质(收敛性)与单位重量核桃仁中多酚对蛋白质的结合能力PPC(ProteinPrecipitationCapacity)关系紧密,核桃仁的PPC值在489.27～610.19(mg/100g)时,核桃的香味比较突出;北方核桃仁(JuglansregiaL)中多酚含量一般比南方铁核桃仁(JuglanssigillataDode)的高,核桃仁种皮颜色也比南方铁核桃仁深。     

花生红衣多酚类物质组成及抑菌活性研究

以花生红衣为原料,采用70%乙醇作溶剂超声辅助提取花生红衣多酚类物质,并进行纯化,研究花生红衣多酚类物质组成及其对食品中常见污染菌的抑菌活性及保鲜性能。结果表明:花生红衣多酚类物质中多酚含量为64.45%,黄酮含量为12.76%,原花青素含量为81.90%,白藜芦醇含量为0.005%。花生红衣多酚类物质对细菌抑菌作用显著,对真菌不显著,且抑菌活性随着质量浓度的增加而增强。     

Polyphenols of tea. IV.—Qualitative and quantitative study of the polyphenols of different organs and some cultivated varieties of tea plant

A method is described for the estimation of individual polyphenols of tea leaf. Polyphenols separated by two-way paper chromatography of a methanolic extract of the material were located under ultra-violet light. The excised spots were eluted with water and estimated from extinctions at 275 nm. Three of the polyphenols, (?)-epigallocatechin gallate, (?)-epigallocatechin and (?)-epicatechin gallate, which comprise 10-19% of the dry matter of tea shoots from Assam, are partly consumed during the manufacture of black tea. Seasonal variation in the polyphenolic content of some jats and clones grown in North East India are described. The phenolic content of the tea shoots was higher during rains. Changes in the phenolic pattern during the growth and development of tea flower, fruit and seed are described. Organs of tea, such as sepals, petals and pericarp with closer morphological affinities to the leaf, showed a greater degree of similarity in their phenolic pattern compared with other organs such as stigma, style, carpel, anther and testa. The gallates were mostly confined to the chlorophyll-bearing organs.     

THE EXTRACTION OF BEER POLYPHENOLS AND THEIR ASSAY BY H.P.L.C.

Polyphenols have been isolated from beer using chromatography on Sephadex LH20 followed by organic solvent extraction. The polyphenols were subsequently assayed by high performance liquid chromatography which showed the isolation procedure to be quantitative for the types of polyphenols present in beer. Batch to batch variation of polyphenol contents in single beer types has been found.     

黄酒中多酚类物质检测方法研究进展

多酚类物质是一种重要的功能性成分,以清除自由基等功效而著称,其存在于黄酒之中,加强对黄酒中多酚类物质检测方法的研究对推动黄酒产业的发展意义重大.文章介绍了多酚的结构性质、提取纯化方法,综述了近年来黄酒中多酚类物质检测方法的研究进展,包括紫外分光光度法、荧光检测法、毛细管电泳-电化学方法、高效液相色谱法等,并对检测方法的发展趋势进行了讨论和展望.     

Extraction of polyphenols and hydrolysis of birdproof sorghum starch

The presence of polyphenols in the testa and pericarp of birdproof sorghum has an inhibitory effect on enzyme activity during hydrolysis of sorghum starch. In this communication the effect of different NaOH concentrations at various temperatures on the extraction of polyphenols from birdproof sorghum is described. It was found that a 0.25 M NaOH solution extracted all the polyphenols within 75 min at 22°C. The enzymic hydrolysis of birdproof sorghum starch (without polyphenols) was also investigated. A recovery of up to 92±0.6% glucose from the available starch was obtained. The change in sugar composition during hydrolysis was monitored by h.p.l.c.     

果蔬中多酚成分及其分析方法的研究进展

果蔬是膳食的重要组成部分,富含多种多酚功能活性成分。多酚是植物的次级代谢产物,具有多种功效。多酚由于其强抗氧化活性,使其具有抗菌、抗病毒和抗炎的作用。天然来源多酚的开发以及在食品中的应用已经成为研究的热点。多酚种类繁多,分离、鉴定较复杂,研究者为了得到高灵敏度、高选择性多酚分析方法进行了大量研究。本文简述了果蔬中的多酚成分,重点介绍了类黄酮、酚酸和单宁;综述了多酚分析方法最近研究进展,重点是基于色谱方法和分离技术的多酚的提取、分离和鉴定。以期为果蔬多酚在食品中的应用提供参考和思路。      

植物膳食多酚及其定量分析方法的研究进展

植物多酚是一种植物次生代谢物, 其结构多样, 具有多种生物活性。本文对近年来研究较多的植物多酚 (茶多酚、葡萄多酚、苹果多酚、石榴多酚、海藻多酚)及其定量分析方法(高压液相色谱法、气相色谱法、毛细管 电泳法, 红外光谱法、核磁共振波谱法及各种联用技术)进行了综述, 以期为植物多酚的后续研究提供参考。     

Drying kinetics of the individual layer of cocoa beans during heat pump drying

Investigation was carried out to study the drying kinetics of the individual layer of cocoa beans, namely the testa and cotyledon, during heat pump drying. The cocoa beans were dried in thin layer using dehumidified air at 28.2 °C, 40.4 °C and 56 °C. Moisture contents of the bean, testa and cotyledon were recorded during drying. Reduction in moisture content was relatively fast at the testa as compared to the cotyledon in the initial two hours of drying. Subsequent drying showed a crossover region where the moisture content of the testa was higher than the cotyledon. The final moisture content of the testa was found to be higher than the inner cotyledon at the end of drying. This showed that moisture migrated from the cotyledon (lower moisture content) to the testa (higher moisture content) during drying. Although such transfer mechanism seems contradict but this can be further explained by the mass transfer potential concept as postulated by Luikov where the transfer of moisture is due to moisture potential difference instead of moisture content difference. Product quality analyses showed percent retention of cocoa polyphenols ranged from 44% to 73% as compared to freeze dried sample. Bean hardness was found reasonably comparable to the commercial sample and increased with decreasing moisture content.     

CHEMICAL CONSTITUENTS OF NYLON-66 BEER ADSORBATE. II. THIN-LAYER CHROMATOGRAPHY OF THE ACIDIC AND ALKALINE HYDROLYSIS PRODUCTS

The preparations obtained from the acidic and caustic desorbates of Nylon-66 beer adsorbates have been submitted to different hydrolytic procedures and the phenolics thus obtained examined by means of uni- and two-dimensional chromatography with the aid of appropriate reference compounds. A number of polyphenols and phenolic as well as cinnamic acids has been identified. The presence of trans-o-coumaric acid has not been previously reported in beer.     

CHEMICAL CONSTITUENTS OF NYLON-66 BEER ADSORBATE. III. COLOUR REACTIONS ON THIN-LAYER AND PAPER CHROMATOGRAMS

A thorough investigation of Nylon-66 adsorbate from a Canadian ale on various chemical constituents has been made using thin-layer and paper chromatography coupled with different colour reactions. In addition to polyphenols, proteins and carbohydrates which are customary constituents of a polyamide beer adsorbate, a number of other types of organic compounds have been identified.     

Enzyme inhibition by polyphenols of sorghum grain and malt

Enzyme production and activity in malt produced from birdproof sorghum cultivars were unaffected by the endogenous polyphenols present in the testa and nucellar layer of the grain. When the rigid segregation of tissues and substances in the malt grain is disrupted by milling, the polyphenols inhibit the endogenous enzymes in aqueous suspensions and reduce the brewing value of the ground malt. Sorghum beer made from malt of birdproof cultivars did not taste bitter. Bird-proof sorghum cultivars differ widely in content and quality of polyphenols inhibiting enzymes. Enzymatic methods are proposed to determine the inhibiting fractions of the polyphenols in sorghum grain. The results of these methods correlate well with DMF-extractable polyphenols assayed by ferric ammonium citrate in alkaline medium. The merits of enzymatic and chemical methods to determine biologically active polyphenols are discussed. Suggestions to protect the brewing industry against unsuitable grain sorghum cultivars of the birdproof class are made.     

Interactions between cell wall polysaccharides and polyphenols

In plant-based food systems such as fruits, vegetables, and cereals, cell wall polysaccharides and polyphenols co-exist and commonly interact during processing and digestion. The noncovalent interactions between cell wall polysaccharides and polyphenols may greatly influence the physicochemical and nutritional properties of foods. The affinity of cell wall polysaccharides with polyphenols depends on both endogenous and exogenous factors. The endogenous factors include the structures, compositions, and concentrations of both polysaccharides and polyphenols, and the exogenous factors are the environmental conditions such as pH, temperature, ionic strength, and the presence of other components (e.g., protein). Diverse methods used to directly characterize the interactions include NMR spectroscopy, size-exclusion chromatography, confocal microscopy, isothermal titration calorimetry, molecular dynamics simulation, and so on. The un-bound polyphenols are quantified by liquid chromatography or spectrophotometry after dialysis or centrifugation. The adsorption of polyphenols by polysaccharides is mostly driven by hydrophobic interactions and hydrogen bonding, and can be described by various isothermal models such as Langmuir and Freundlich equations. Quality attributes of various food and beverage products (e.g., wine) can be significantly affected by polysaccharide–polyphenol interactions. Nutritionally, the interactions play an important role in the digestive tract of humans for the metabolism of both polyphenols and polysaccharides.     

花生红衣总多酚抑制酪氨酸酶活性和抗氧化作用研究

通过单因素实验和正交实验,确定了闪式提取花生红衣总多酚的最佳工艺条件;并研究了花生红衣总多酚对酪氨酸酶的抑制作用及清除DPPH自由基的能力。闪式提取最佳工艺条件为:乙醇浓度80%,料液比1∶25(g/mL),提取电压90V,提取3次,每次2min,该条件下,花生红衣总多酚的平均提取率为96.94%;花生红衣总多酚对酪氨酸酶的抑制率达到50%(IC50)时所需的花生红衣总多酚的质量浓度为0.451mg/mL,最高抑制率可达89.65%;并且花生红衣总多酚清除DPPH自由基的能力大于VC,稍弱于没食子酸。      

葡聚糖凝胶LH-20分离制备生物碱、无咖啡碱茶多酚和茶色素工艺研究

本研究建立了一种环保高效同时分离制备生物碱、无咖啡碱茶多酚和茶色素的葡聚糖凝胶LH-20柱层析方法。第一步使用蒸馏水分离茶色素和生物碱;第二步采用60%（v/v）乙醇溶液反向洗脱得到无咖啡碱茶多酚产品。经定量分析,生物碱得率3.14%,其中含93.87%咖啡碱和6.08%可可碱。茶多酚的得率为12.27%,纯度为98.13%,其中儿茶素含量高达90.28%,抗氧化活性最强的EGCG含量达61.17%,咖啡碱未检出。柱层析对生物碱和茶多酚的回收率分别为98.14%和86.36%。副产的茶色素主要含有一些多酚氧化物以及黄酮苷类混合物,可作为天然色素利用。