不同品种梨果实酚类物质和抗氧化性能分析

以我国北方11 个主栽梨品种黄冠、绿宝石、雪梨、鸭梨、丰水、南水、圆黄、黄金、华山、五九香和早酥的果实为试材,分别测定了果皮、果心和果肉中可溶性酚的含量,并对酚类物质进行了高效液相色谱（highperformance liquid chromatography,HPLC）分析。通过分别测定果皮、果肉、果心的乙醇提取液对DPPH自由基和羟自由基的清除能力,对其所含酚类物质的抗氧化性能进行了评价。结果表明：1）梨果心酚类物质含量高于果皮,果肉最低;2）在果心和果皮中均检测出熊果苷、没食子酸、儿茶素、绿原酸、咖啡酸、表儿茶素、香豆酸和芦丁8 种酚类物质,而在果肉中检测出熊果苷、没食子酸、绿原酸、表儿茶素和芦丁5 种物质;3）熊果苷、绿原酸和表儿茶素都为果肉和果皮的主要酚类物质,果肉中绿原酸的含量高于熊果苷,果皮则反之,果心所含酚类物质以绿原酸和熊果苷为主,且绿原酸的含量高于熊果苷;4）果皮、果肉、果心不同部位的酚类物质的含量与1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除能力和羟自由基清除能力间均分别呈显著正相关关系,表明酚类物质与自由基清除能力的关系密切。     

4个甜樱桃品种品质指标和酚类物质比较

以美早、先锋、雷尼、拉宾斯4个品种的甜樱桃为研究对象,对品种间品质指标及酚类物质的相关性进行分析。结果表明,4个品种中美早甜樱桃的果皮硬度、可溶性固形物含量最高,分别为5.26 kg/cm2和15.47%,而雷尼甜樱桃的a*值、果肉硬度、可溶性固形物含量和固酸比最小,b*值和总酸含量最高。从酚类物质含量和组成来看,甜樱桃果肉中含量较高的酚类物质是表儿茶素、对香豆酸、儿茶素和芦丁,美早和先锋甜樱桃果肉的绿原酸含量高于拉宾斯和雷尼,但咖啡酸含量较低。美早、先锋、拉宾斯甜樱桃的果皮中,均是对香豆酸、表儿茶素和芦丁含量较高,但在雷尼果皮中,表儿茶素（226.19 μg/g）含量最高。相关性分析表明,甜樱桃果肉L*值与儿茶素和表儿茶素呈高度显著正相关（P＜0.001）,b*值与表儿茶素呈高度显著正相关（P＜0.001）,与总酸、儿茶素极显著正相关（P＜0.01）。     

苹果酒中酚酸、黄烷-3-醇的检测

以小国光(Ralls)和富士(Fuji)及其所酿制的新鲜苹果酒为试验材料,采用反相高效液相色谱法测定分析苹果原汁、发酵中酒样和苹果成品酒中11种酚酸、5种黄烷-3-醇的含量。结果表明:苹果和苹果酒中存在4种酚酸(原儿茶酸、绿原酸、咖啡酸、对-香豆酸)、2种黄烷-3-醇(儿茶素和表儿茶素);不同品种的苹果原汁和苹果成品酒中酚类物质的含量都存在显著差异。其中,小国光苹果和小国光苹果酒中的酚类物质总含量较高;对于每个品种,绿原酸都是最主要的酚酸类物质,含量最高的黄烷-3-醇类物质都是表儿茶素。随着发酵过程的进行,苹果酒中酚类物质的含量有不同程度的增加。其增加趋势为S型曲线,即先平缓再较快再平缓。     

中早熟苹果品种的贮藏品质和酚类物质差异分析

中早熟苹果品种可以丰富水果市场,是苹果产业重要的组成部分,研究其贮藏特性及品质差异意义重大。本实验以‘鲁丽’‘鲁艳’两个苹果新品种为研究对象,以其亲本‘嘎啦’为参照,探究3种苹果的贮藏品质和酚类物质差异。结果表明：相比于‘嘎啦’苹果,‘鲁丽’苹果可溶性固形物质量分数最高,果皮a*值最大,外观品质最佳、适于鲜食,而‘鲁艳’苹果总酸度高、固酸比低,贮藏期间乙烯释放量高,不耐贮藏。与‘嘎啦’和‘鲁艳’苹果相比,‘鲁丽’苹果有着最高的总酚、总黄酮含量和1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除率,抗氧化能力最强。3种苹果主要的酚类物质也因品种、成熟度和果实部位存在差异,‘嘎啦’和‘鲁丽’苹果果肉均以绿原酸含量最高,而‘鲁艳’苹果表儿茶素含量最高,果皮酚类物质含量高于果肉。相关性和主成分分析表明果实硬度与a*值有高度显著负相关性（P<0.001）,可溶性固形物质量分数与总酚、总黄酮、绿原酸含量和DPPH自由基清除率存在高度显著正相关（P<0.001）,主成分1主要由总酚、总黄酮、绿原酸、表儿茶素含量等指标决定,成熟...     

苹果品种和酿造工艺对苹果酒中酚类物质的影响研究

研究不同苹果品种及加工工艺与苹果酒中最终酚类物质的含量和种类的关系,了解不同苹果酒中酚类物质含量的差异.选用甘肃天水提供的两种不同工艺的6款苹果酒样,测定其中的总酚、酚酸及黄烷-3-醇的含量.苹果酒的总酚含量(以没食子酸计)较高,3种苹果酒中的主要酚类物质中,酚酸主要以原儿茶酸、绿原酸、p-香豆酸以及咖啡酸为主;黄烷-3-醇以儿茶素和表几茶素居多.结果表明,不同苹果品种之间酚类物质的含量及类别差异很大,相同品种的苹果酒中多酚的构成及含量会受到酿造工艺的影响.     

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。     

柑橘果肉、果皮中酚类物质含量差异性研究

采用高效液相色谱法(high performance liquid chromatographic,HPLC)对8种橙类和杂柑中10种酚类物质含量进行测定,探讨不同柑橘品种果肉和果皮中酚类物质种类和含量的差异,分析其规律。结果表明,10种物质能在55 min内分离,线性范围为0.25~200 mg/L,相关系数达0.999 1~1,精密度(RSD≤1.90%)、重复性(RSD≤3.52%)和稳定性(RSD≤4.22%)较好,平均回收率为90.26%~118.85%(RSD为0.96%~3.01%),表明方法的准确度较高。在橙类和杂柑中,橙类果皮中芥子酸含量显著高于杂柑,杂柑果皮中芦丁含量显著高于橙类;果肉中酚类物质含量低于果皮;果实中酚酸以咖啡酸和绿原酸为主,类黄酮以芦丁和柚皮苷为主;在8个柑橘品种果肉中,金诺的阿魏酸、没食子酸和芦丁含量最高。在8个柑橘品种果皮中,口之津32号的咖啡酸、阿魏酸、对羟基苯甲酸含量最高,沃柑的新橙皮苷、柚皮苷、没食子酸和绿原酸含量最高。     

山楂多酚含量的反相高效液相色谱法测定

建立同时测定山楂中绿原酸、表儿茶素和芦丁3 种酚类物质的反相高效液相色谱方法,并研究这三种酚类物质在山楂干果果肉、干果果核和鲜果果肉中的含量。经测定,表儿茶素在山楂鲜果果肉中含量最高,达到(1.661 ± 0.024) mg/g;绿原酸和芦丁在山楂干果果肉中含量最高,分别达到(0.550 ± 0.002) mg/g 和(0.498 ± 0.002) mg/g。本方法样品处理简单,具有良好的重现性和线性,相关性系数均达到0.999,绿原酸、表儿茶素和芦丁的回收率分别为91.8%～110.9%、94.6%～107.9% 和94.2%～108.8%;检出限分别为0.14、0.37 和0.68μg/ml (S/N ＝ 3)。     

HPLC法测定苹果浓缩汁中的多酚类物质

利用高效液相色谱法(HPLC)分析了儿茶素、绿原酸、咖啡酸、表儿茶素、香豆酸、阿魏酸等六种酚类物质在鲁加1号和鲁加5号苹果浓缩汁中的的含量.色谱条件:色谱柱为EdipseXDB-C18色谱柱(150mm×4.6mm id,5μm),以甲醇-1%乙酸水溶液作为流动相进行梯度洗脱.柱温30℃,流速为1.0ml/min,检测波长为280nm.在此色谱条件下,各组分均得到很好的分离.经测定鲁加1号苹果浓缩汁中含有儿茶素、绿原酸、咖啡酸、表儿茶素、香豆酸、阿魏酸等六种酚类物质;鲁加5号苹果浓缩汁中含有较少的绿原酸、咖啡酸、表儿茶素、香豆酸、阿魏酸等五种酚类物质.     

货架温度结合1-甲基环丙烯处理对采后‘乔纳金’苹果酚类物质的影响

苹果含有多种功能性酚类物质,但对其采后货架期间的变化规律尚无系统研究。本实验以‘乔纳金’苹果 为材料,研究1-甲基环丙烯（1-methylcyclopropene,1-MCP）处理后贮藏3 个月,货架时间和温度对果皮和果肉中 5 种单体酚含量的影响。结果表明：‘乔纳金’苹果果皮中金丝桃苷含量最高,果肉中绿原酸含量最高,随着货架时 间的延长,‘乔纳金’果实中金丝桃苷、绿原酸、槲皮素、芸香叶苷及总酚含量均呈现下降趋势,而根皮苷含量呈上 升趋势。1-MCP有效地延缓了贮藏期和货架期果皮、果肉中金丝桃苷、总酚含量的下降和根皮苷含量的上升。     

不同品种苹果化学成分及抗氧化活性比较

测定13种苹果的L-抗坏血酸、可溶性糖、滴定酸和总酚含量及pH值,比较13种苹果的抗氧化活性,包括还原力、脂质过氧化抑制率、 ·OH和DPPH自由基清除率,并依据化学成分对13种苹果进行聚类分析。结果表明,13种苹果的化学成分及抗氧化活性有差异,其中以新红星、藤牧1号和延光的抗氧化活性最强,而秦冠、粉红女士和红富士的抗氧化活性最小。苹果中的总酚含量与抗氧化活性之间显著正相关,两者均受基因型影响。聚类结果显示,美国八号、太平洋红玫瑰为抗坏血酸含量最高的一类,可溶性糖含量较高的乔纳金、太平洋红玫瑰、粉红女士、秦冠和红富士聚为一类,粉红女士为滴定酸含量最高的一类,糖酸比最高的一类是秦冠和红富士,藤牧1号、延光、新红星和乔纳金的总酚含量较高。     

Monomeric phenolics in different parts of high‐acid apple (Malus sieversii f. niedzwetzkyana (Dieck) Langenf): a promising source of antioxidants for application in nutraceuticals

The high‐acid apple (Malus sieversii f. niedzwetzkyana (Dieck) Langenf) possessing deep red peel and light red flesh is widely distributed in China. To determine if a useful apple variety is being ignored, the monomeric phenolic profiles and antioxidant activities of peel, flesh, pomace, whole fruit and juice were evaluated. The results were compared to those of ‘Fuji’ and ‘Granny Smith’ apples. The high‐acid apple possessing the highest total phenolic and anthocyanin contents among three apple varieties contained the most chlorogenic acid, phloridzin, epicatechin, ferulic acid, catechin, vanillic acid, p‐coumaric acid and caffeic acid. The extraction yields of phenolics (64%) and anthocyanins (89%) from the high‐acid apple to juice were the highest. The high‐acid apple possessing the greatest antioxidant activity had the strongest antihaemolysis activity, indicating that it could be used to produce juice and value‐added ingredient to assist in the prevention of chronic disease.     

Flavonoid and chlorogenic acid profiles of English cider apples

The phenolics in 20 apple cultivars comprising 19 English cider apple varieties and one dessert apple variety were analysed by high‐performance liquid chromatography/tandem mass spectrometry. The cider varieties contained higher levels than the dessert apple and the peel was richer in phenolics than the flesh. The phenolic concentrations ranged between 230 and 4920 mg kg^?1 fresh weight in the flesh and between 546 and 6306 mg kg^?1 fresh weight in the peel. Fifteen compounds from five different phenolic groups, flavan‐3‐ols, flavonols, anthocyanins, hydroxycinnamates and dihydrochalcones, were detected. The major components in the flesh were 5‐O‐caffeoylquinic acid, procyanidin B2 and (?)‐epicatechin, while (?)‐epicatechin and quercetin glycosides predominated in the peel. Copyright © 2007 Society of Chemical Industry     

Phenolic compounds in some apple (Malus domestica Borkh) cultivars of organic and integrated production

Eleven organically grown apple cultivars and 11 apple cultivars of integrated production from Austria and Slovenia were analyzed by HPLC for the content of phenolic compounds in peel and pulp. We identified chlorogenic acid, p‐coumaric acid, procyanidin B3, protocatechuic acid, (?)‐epicatechin, phloridzin, rutin and quercetin‐3‐rhamnoside in apple peel. In apple pulp, (+)‐catechin was also identified in all the cultivars. Some other phenols (procyanidin B3, rutin and quercetin‐3‐rhamnoside) could not be identified or were not properly separated. With regard to the phenolic content in the apple peel, there were no differences between organically grown apple cultivars and apple cultivars of integrated production. Organically grown apples, however, exhibited a higher content of phenolic substances in the apple pulp compared with the apple cultivars of integrated production. This may be due either to the different genotype source or to the growing technology. Higher concentrations of phenolic compounds in organically grown cultivars could be a result of plant response to stress. The apple peel contained higher concentrations of identified phenols than the pulp. The apple peel represents up to 10% of the whole fruit; therefore the phenolsic compounds in the pulp are of greater importance to the consumer than the phenolic compounds in the peel. Copyright © 2005 Society of Chemical Industry     

Polyphenol and glycoalkaloid contents in potato cultivars grown in Luxembourg

The polyphenol (phenolic acids, flavanols and flavonols) and glycoalkaloid (α-chaconine and α-solanine) contents of potato tubers grown in Luxembourg were analyzed by UPLC–DAD and HPLC–MS/MS separately in peel (approx. 2 mm), outer (approx. 1 cm) and inner flesh. Polyphenol contents decreased from the peel via the outer to the inner flesh and differed among the cultivars. The cultivars Vitelotte and Luminella had the highest polyphenol contents (5202 and 572 μg/g dry weight (DW) in the outer flesh), whereas Charlotte and Bintje had the lowest contents (19.5 and 48.0 μg/g DW). Chlorogenic acid and its isomers (neo- and cryptochlorogenic acid) were the major polyphenols. Glycoalkaloid contents were highest in the peel and lowest in the inner flesh, values in the flesh were below guideline limits in all cultivars. In conclusion, potatoes contribute to the daily intake of polyphenols and their consumption, thereby, may have positive effects on health.     

Comparative study of six pear cultivars in terms of their phenolic and vitamin C contents and antioxidant capacity

The main phenolic compounds in six pear cultivars were identified and quantified using high‐performance liquid chromatography/diode array detection (HPLC/DAD) and HPLC/electrospray ionisation mass spectrometry (HPLC/ESIMS). Major quantitative differences were found in the phenolic profiles. The peel contained higher concentrations of chlorogenic acid, flavonols and arbutin than the flesh, where only chlorogenic acid was detected. Total phenolics ranged from 1235 to 2005 mg kg^?1 in the peel and from 28 to 81 mg k g^?1 in the flesh. Ascorbic acid and dehydroascorbic acid were detected in the peel, whereas only dehydroascorbic acid was present in the flesh. The ranges of vitamin C content were from 116 to 228 mg kg^?1 in the peel and from 28 to 53 mg kg^?1 in the flesh. The antioxidant capacity was correlated with the content of chlorogenic acid (r = 0.46), while ascorbic acid made only a small contribution to the total antioxidant capacity of the fruit. Copyright © 2003 Society of Chemical Industry     

Changes of contents and antioxidant activities of polyphenols during fruit development of four apple cultivars

Polyphenols are functional components in apples and can be separated into four groups by Sephadex LH-20 as epicatechin, procyanidolic oligomers, chlorogenic acid and procyanidolic polymers. Antioxidant activities of each group were determined by FRAP and DPPH radical scavenging assay. It was found that procyanidolic oligomers and procyanidolic polymers influenced the total polyphenols content (measured by Folin–Ciocalteu method) much more in Jonagold, Golden Delicious, Fuji and Guoguang four apple cultivars. The Fe-reducing activity of procyanidolic oligomers in the four apple cultivars increased significantly during the development while the other three compounds changed irregularly. And the Fe-reducing activities of epicatechin and procyanidin contributed much more to the total Fe-reducing activities during the fruit development in the four apple cultivars. The DPPH scavenging activities of four compounds in Jonagold and Golden Delicious decreased during fruit development and that of Fuji and Guoguang changed irregularly. Chlorogenic acid was the main contributor in Jonagold, Golden Delicious and Fuji to the total scavenging activity. In Guoguang, it was procyanidolic oligomers that contributed much to the total scavenging activity.