不同品種石榴多酚提取工藝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：齊　迪　　導(dǎo)師：房玉林

西北農(nóng)林科技大學(xué)　　食品工程領(lǐng)域2011屆工程碩士

摘　要

多酚是石榴果實(shí)的重要功能性成分之一。本研究以產(chǎn)自陜西臨潼和四川攀枝花的6個(gè)石榴品種為試材，對果實(shí)多酚物質(zhì)提取工藝、含量及抗氧化活性進(jìn)行了研究，旨在為石榴的綜合應(yīng)用和開發(fā)提供理論依據(jù)。以80%的酸化甲醇作為提取劑，并結(jié)合超聲波輔助功效，通過設(shè)計(jì)單因素和正交試驗(yàn)，確定了石榴多酚提取的最佳提取條件和提取效果；對石榴果皮、內(nèi)隔膜和石榴籽粒中重要的酚類物質(zhì)（總酚、總類黃酮、原花青素及單體酚）及抗氧化活性（DPPH清除力、銅離子還原力、鐵氰化鉀還原力、超氧陰離子自由基清除能力）進(jìn)行了評估；對6個(gè)石榴品種進(jìn)行了單品種釀酒實(shí)驗(yàn)。

主要研究結(jié)果如下：

（1）超聲波輔助法提取石榴多酚的最佳工藝：80%的酸化甲醇為萃取劑，料液比為1:20，提取時(shí)間20min，提取溫度30℃，提取級數(shù)一次。超聲波固定功率100W。石榴皮總酚提取率為14.06mg/g。

（2）測量石榴果皮、內(nèi)隔膜和石榴籽粒中重要的酚類物質(zhì)，結(jié)果表明，總酚與總黃酮含量呈現(xiàn)出相同的規(guī)律性：在石榴皮中含量最高，其次是內(nèi)隔膜，含量最低的部位是石榴籽粒。石榴皮、石榴內(nèi)隔膜和石榴籽粒中總酚含量在1.07mg/g～13.86mg/g之間，總黃酮含量在0.41 mg/g～11.98mg/g之間。原花青素的平均含量為0 mg/g～5.57mg/g。

石榴皮和石榴內(nèi)隔膜中多酚類物質(zhì)含量豐富，本研究共檢測了10種單體酚類物質(zhì)，其中含量較高的單體酚為沒食子酸，其含量最高可達(dá)2358.67mg/L，其次為安息香酸、兒茶素、咖啡酸、阿魏酸等，其余單體酚含量均很低。

（3）測定了6個(gè)石榴品種果皮、內(nèi)隔膜和石榴籽粒等不同部位酚類提取物質(zhì)的抗氧化能力，結(jié)果表明：從不同組織部位提取出來的石榴多酚抗氧化能力各不相同。果皮、內(nèi)隔膜和籽粒的超氧陰離子自由基清除能力和DPPH清除能力趨于一致,分別在45.75%～86.19%和79.67%～90.9%之間。測得的鐵氰化鉀還原力和銅離子還原力Trolox當(dāng)量分別在46.62mg/g～456.49mg/g 和50.63mg/g～376.88 mg/g之間。

（4）對于單品種石榴果酒，經(jīng)過品嘗小組的感官品嘗，綜合得分最高的是路一丹品種釀制石榴酒，其次是攀枝花、三白甜、大紅甜、凈皮甜和酸石榴。

關(guān)鍵詞　石榴　酚類物質(zhì)　抗氧化　提取工藝　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