不同品种石榴多酚提取工艺及其抗氧化活性的研究

不同品种石榴多酚提取工艺及其抗氧化活性的研究

STUDY ON THE POLYPHENOL EXTRACTION METHODS AND TOTALANTIOXIDANT CAPACITY OF DIFFERENT POMEGRANATE VERIETIES

作者：齐　迪　　导师：房玉林

西北农林科技大学　　食品工程领域2011届工程硕士

摘　要

多酚是石榴果实的重要功能性成分之一。本研究以产自陕西临潼和四川攀枝花的6个石榴品种为试材，对果实多酚物质提取工艺、含量及抗氧化活性进行了研究，旨在为石榴的综合应用和开发提供理论依据。以80%的酸化甲醇作为提取剂，并结合超声波辅助功效，通过设计单因素和正交试验，确定了石榴多酚提取的最佳提取条件和提取效果；对石榴果皮、内隔膜和石榴籽粒中重要的酚类物质（总酚、总类黄酮、原花青素及单体酚）及抗氧化活性（DPPH清除力、铜离子还原力、铁氰化钾还原力、超氧阴离子自由基清除能力）进行了评估；对6个石榴品种进行了单品种酿酒实验。

主要研究结果如下：

（1）超声波辅助法提取石榴多酚的最佳工艺：80%的酸化甲醇为萃取剂，料液比为1:20，提取时间20min，提取温度30℃，提取级数一次。超声波固定功率100W。石榴皮总酚提取率为14.06mg/g。

（2）测量石榴果皮、内隔膜和石榴籽粒中重要的酚类物质，结果表明，总酚与总黄酮含量呈现出相同的规律性：在石榴皮中含量最高，其次是内隔膜，含量最低的部位是石榴籽粒。石榴皮、石榴内隔膜和石榴籽粒中总酚含量在1.07mg/g～13.86mg/g之间，总黄酮含量在0.41 mg/g～11.98mg/g之间。原花青素的平均含量为0 mg/g～5.57mg/g。

石榴皮和石榴内隔膜中多酚类物质含量丰富，本研究共检测了10种单体酚类物质，其中含量较高的单体酚为没食子酸，其含量最高可达2358.67mg/L，其次为安息香酸、儿茶素、咖啡酸、阿魏酸等，其余单体酚含量均很低。

（3）测定了6个石榴品种果皮、内隔膜和石榴籽粒等不同部位酚类提取物质的抗氧化能力，结果表明：从不同组织部位提取出来的石榴多酚抗氧化能力各不相同。果皮、内隔膜和籽粒的超氧阴离子自由基清除能力和DPPH清除能力趋于一致,分别在45.75%～86.19%和79.67%～90.9%之间。测得的铁氰化钾还原力和铜离子还原力Trolox当量分别在46.62mg/g～456.49mg/g 和50.63mg/g～376.88 mg/g之间。

（4）对于单品种石榴果酒，经过品尝小组的感官品尝，综合得分最高的是路一丹品种酿制石榴酒，其次是攀枝花、三白甜、大红甜、净皮甜和酸石榴。

关键词　石榴　酚类物质　抗氧化　提取工艺　石榴酒

Abstract

Polyphenols is one of the important functional ingredients in pomegranates. Five pomegranate varieties produced in Shaanxi Lintong area and one from Sichuan Panzhihua as test materials,the experiment was conducted to study on polyphenol extraction technology and polyphenol content and antioxidant activity,and aimed to provide theoretical basis for the comprehensive application and development of pomegranate. 80% of acidification methanol as extraction agents,combined with ultrasonic auxiliary efficacy,through designing single factor tests and orthogonal test,finally it was determined that the best extraction conditions and extraction effect. Important phenolics compounds(total phenol，total flavonoids,OPC and mono- phenolics) and antioxidant activity(DPPH,CUPRAC,PFRAP,SRSA)were evaluated in pomegranate peel,inner diaphragm and pomegranate seed. At the last,we have the single variety winemaking experiment use the six pomegranates varieties.

It could be concluded from this experiment:

（1）The optimal process of extraction of the total polyphenols from granatum with ultrasonic wave(fixed power 100W) were as follows: radio of solid to liquid 1:20(g/mL),temperature 30℃,extracting duration 20 min,once ultrasonic extraction process. The extracting rate of total polyphenol was 14.06mg/g.

（2）Measuring important phenolic compounds in pomegranate peels,inner diaphram and seeds. It indicated that Total polyphenol and the flavonoids content presents the same regularity. The pomegranate peels has the highest levels,second one is in the diaphragm. The lowest part is in pomegranate seed. Total phenolic compounds (TP)in pomegranate peels,diaphragm and seeds ranged from 1.07 to 13.86 mg gallic acid equivalents g. Total Flavonoids (TFO) in pomegranate peels,diaphragm and seeds ranged from 0.41 to 11.98 mg catechins acid equivalents g. Proanthocyanidin (PC) ranged from 0 to 5.57 mg catechins acid equivalents g.

Composition and content analysis showed that Pomegranate peels and diaphragm is rich in polyphenols. Ten components had been identified in different extracts，and the major components is gallic acid with the content of 2358.67mg/g,followed by less contents of benzoic acid,catechin,caffeic acid and ferulic acid etc. The content of mono-polyphenols in others is all low.

（3）The anti-oxidation ability of each sample were measured. It indicated that peel,inner diaphragm and seeds of superoxide radical scavenging capacity and DPPH clear ability to converge. Polyphenols extracted from different organizations parts of pomegranate has different antioxidant capacity respectively. Superoxide Radical Scavenging Activity ranged from 45.75 to 86.19%. DPPH Radical Scavenging Capacity ranged from 79.67 to 90.9%. Potassium Ferricyanide Reducing Power (PFRAP) and Cupric Reducing Antioxidant Power (CUPRAC) ranged from 46.62 to 456.49 and 50.63 to 376.88 mg of trolox equivalents g,respectively.

（4）For single variety pomegranate wine,after tasting team senses tasting,integrated highest scoring is Luyidan,next is Panzhihua,and then Sanbaitian,Ddanhongtian,Jingpitian and Sour pomegranates.

Key words　Pomegranate　Polyphenol　Anti-oxidation　Technological processes　Pomegranate wine