摘要
油茶籽种皮富含多种活性成分,本文通过探讨不同预处理方法对油茶籽种皮成分、结构和抗氧化活性的影响,为实现油茶籽种皮变废为宝和深加工利用提供科学依据。对比了酸法、碱法、亚临界水和离子液体4种预处理方法所得海南油茶籽种皮中的总酚含量、纤维素组成,并运用扫描电镜(SEM)、X-射线衍射(XRD)、傅里叶变换红外光谱(FTIR)、核磁共振氢谱(^(1)H NMR)和差示扫描量热仪(DSC)表征4种预处理方法所得油茶籽种皮的结构。在此基础上,利用DPPH、ABTS和还原力体外抗氧化体系评价4种预处理方法所得油茶籽种皮的抗氧化活性。结果表明,4种预处理方法均会降低油茶籽种皮得率、半纤维素和木质素含量,其中以亚临界水处理种皮得率损失最小[(80.07±0.01)%],而酸法和碱法处理后纤维素含量[(39.36±0.40)%、(36.67±0.74)%]基本不损失,与原料[(38.83±3.81)%]差异不显著。不同预处理方法能够使油茶籽种皮纤维比表面积增大、表面孔洞增加,使纤维结构的无定型区比例升高;未经处理的油茶籽种皮原料强度较大,结晶指数为41.67,其次是酸法、碱法、亚临界水和离子液体处理所得油茶籽种皮结晶指数,分别为28.37、28.69、27.34和25.17。此外,原料的抗氧化活性最好、酸法和亚临界水处理样品次之、而碱法和离子液体处理样品最差,这与油茶籽种皮中总酚和单宁含量高低基本一致。上述结果表明,酸法和亚临界水预处理优于碱法和离子液体,活性物质稳定性好,损失小。
Camellia episperm contains a lot of bioactive constituents with potential industry values.In this study,the effects of different pretreatment methods on the composition,structure,and antioxidant activity of Hainan camellia oleifera epispermwere investigated.The total phenol content and cellulose compositions in the camellia episperm obtained by four pretreatment methods,including acid method,alkali method,subcritical water,and ionic liquid,were compared.The scanning electron microscope(SEM),X-ray diffraction(XRD),Fourier transform infrared spectrum(FTIR),hydrogen spectrum nuclear magnetic resonance(^(1)H NMR)and differential scanning calorimetry(DSC)were used to characterize the structures of camellia episperm obtained from the four pretreatment method.Moreover,the antioxidant activity was studied by ABTS,DPPH and reductive antioxidant system in vitro.The results showed that the four pretreatment methods could reduce the seed peel yield,hemicellulose and lignin content of camellia episperm,the yield of raw material was(38.83±3.81)%,the yield of episperm treated with subcritical water was(80.07±0.01)%,so the loss was the smallest,while the content of cellulose treated with acid and alkali was(39.36±0.40)%and(36.67±0.74)%,so there was no significant difference with raw material.The pretreatment methods could make the fiber surface and pore volume increased,while the proportion of amorphous area increased,and the crystallinity of cellulose decreased.The untreated material had higher strength with crystallinity index of 41.67,followed by those from acid method,alkali method,subcritical water,and ionic liquid,whose crystallinity index were 28.37,28.69,27.34,and 25.17,respectively.In addition,untreated material had the best antioxidant activity,followed by the acid and subcritical water pretreated samples,while the alkali and ionic liquid pretreated samples had the worst antioxidant activity,which was constant with the results of the total phenolic content and tannin content.The results indicated that the acid and subcritical water pretreatment had advantage of better stability and smaller loss of bioactive constituents,which would provide scientific basis for camellia episperm processing.
作者
吴颍颍
盛占武
郑晓燕
云永欢
陈海明
张伟敏
WU Yingying;SHENG Zhanwu;ZHENG Xiaoyan;YUN Yonghuan;CHEN Haiming;ZHANG Weimin(College of Food Science and Engineering,Hainan University,Haikou,Hainan 570228,China;Engineering Research Center for Tropical Polysaccharide Resources Utilization,Ministry of Education,Haikou,Hainan 570228,China;Haikou Experimental Station,Chinese Academy of Tropical Agricultural Sciences,Haikou,Hainan 571101,China)
出处
《热带作物学报》
CSCD
北大核心
2021年第2期553-561,共9页
Chinese Journal of Tropical Crops
基金
海南省重大科技计划项目“海南油茶优质高产关键技术及加工产品研发”(No.ZDKJ2017004)。
关键词
油茶籽种皮
预处理
结构表征
抗氧化活性
camellia episperm
pretreatment
structure characterization
antioxidant activities