核桃副产物多酚的提取及其对油脂氧化稳定性的影响

发布时间：2019-02-16 12:50

【摘要】：以天然抗氧化剂取代合成抗氧化剂是此后食品工业发展的趋向,因此开发实用、高效、价格低廉的天然抗氧化剂仍是现在抗氧化剂研究的重点。近年来,随着我国现代化农业产业结构的不断调整,围绕着新疆林果产业迅猛发展,核桃油的大量生产刻不容缓,而天然抗氧化剂取代合成抗氧化剂是急需研究和解决的问题,利用现代高新技术在更高层次上对新疆核桃进行综合利用,变废为宝,可为核桃的开发提供理论依据。为了探明核桃不同组织部位的体外抗氧化活性,提高核桃的综合开发利用程度,本研究通过用不同溶剂提取核桃不同部位的多酚物质和黄酮物质,优化核桃多酚物质的提取方法、黄酮物质的提取方法,测定其中含量。通过清除DPPH自由基、ABTS自由基评价其体外总抗氧化活性。结果表明:核桃不同部位多酚类物质和黄酮类物质分别含量为0.838-53.89 mg/g、0.07-0.997mg/g,其中核桃分心木多酚和黄酮含量最高,抗氧化活性也最高,核桃囊衣次之,核桃壳中含量最低。相关性分析表明,除核桃仁之外,核桃其它部位起抗氧化作用的成分主要是多酚和黄酮,其含量与抗氧化活性呈显著正相关。核桃不同部位多酚类物质含量丰富,均具有较高开发新型功能性食品的可行性。将从核桃青皮、囊衣、分心木、核桃壳四个不同部位提取的多酚按不同比例添加到核桃油中,根据核桃油贮藏过程中POV的变化,筛选出最佳的添加物和添加量。选用Schaal烘箱加速法来探讨,在添加不同抗氧化物质条件下,观察核桃油的氧化稳定性情况,通过对过氧化值和酸价、碘值的测定,折光率、相对密度、色度、共轭二烯、共轭三烯、茴香胺值、脂肪酸、VE含量的变化,同时以不添加任何抗氧化物质的核桃油和添加合成抗氧化剂TBHQ的核桃油做对照,研究核桃不同部位提取的抗氧化物质对核桃油氧化稳定性的影响,以此来推断油品的贮藏期限。实验结果表明,核桃囊衣、分心木、青皮多酚优于核桃壳多酚。在核桃油中,添加一定量的多酚类物质,随着时间的延长,核桃油过氧化值和酸价上升趋势减缓,其他各项指标的测试结果也表明,抗氧化剂的活性大小为:TBHQ青皮多酚分心木多酚囊衣多酚空白对照;添加0.05%的核桃青皮多酚的核桃油货架期由4个月延长至6.5个月。
[Abstract]:Replacing synthetic antioxidants with natural antioxidants is the trend of food industry since then, so the development of practical, efficient and inexpensive natural antioxidants is still the focus of antioxidant research. In recent years, with the continuous adjustment of modern agricultural industrial structure in China and the rapid development of forestry and fruit industry in Xinjiang, the mass production of walnut oil is urgent, and it is urgent to study and solve the problem that natural antioxidants replace synthetic antioxidants. The comprehensive utilization of walnut in Xinjiang on a higher level by using modern high technology can provide theoretical basis for the development of walnut. In order to find out the antioxidant activity of different parts of walnut in vitro and improve the comprehensive development and utilization of walnut, the polyphenols and flavonoids of different parts of walnut were extracted with different solvents. The extraction method of walnut polyphenols and the extraction method of flavonoids were optimized and the content of them was determined. The total antioxidant activity was evaluated by scavenging DPPH radical and ABTS radical in vitro. The results showed that the contents of polyphenols and flavonoids in different parts of walnut were 0.838-53.89 mg/g,0.07-0.997mg/g, respectively. The content of walnut capsule was the lowest in walnut shell. Correlation analysis showed that the main antioxidative components of walnut except walnut kernel were polyphenols and flavonoids, the content of which was positively correlated with antioxidant activity. The content of polyphenols in different parts of walnut is abundant, and it is feasible to develop new functional food. The polyphenols extracted from four different parts of walnut green peel, sac, distraction wood and walnut shell were added to walnut oil in different proportion. According to the change of POV during storage, the optimum additive and amount were selected. The oxidation stability of walnut oil was studied by using Schaal oven accelerated method. The oxidation stability of walnut oil was observed by measuring peroxide value and acid value, iodine value, refractive index, relative density, chroma, conjugated diene, etc. The changes of conjugated triene, anisome value, fatty acid, VE content, and the comparison between walnut oil without any antioxidant substance and walnut oil with synthetic antioxidant TBHQ. The effects of antioxidants extracted from different parts of walnut on the oxidative stability of walnut oil were studied in order to infer the storage time of walnut oil. The results showed that walnut coat, distraction wood and green skin polyphenols were superior to walnut shell polyphenols. When a certain amount of polyphenols was added to walnut oil, the increasing trend of peroxide value and acid value of walnut oil slowed down with the prolongation of time. The activity of antioxidant was as follows: TBHQ green skin polyphenol distraction wood polyphenol capsule polyphenols blank control; The shelf life of walnut oil supplemented with 0.05% walnut green peel polyphenols was extended from 4 months to 6.5 months.
【学位授予单位】：塔里木大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TS202.3;TS221

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