5种核桃蛋白特性比较研究  

Comparative Study on the Characteristics of Five Walnut Proteins

作　　者：张彤[1] 庞晓宇 刘莹莹 郭聪聪[1] 田益玲[1,2] ZHANG Tong;PANG Xiaoyu;LIU Yingying;GUO Congcong;TIAN Yiling(Hebei Agricultural University,Baoding 071000,China;Walnut Technology Innovation Center of Hebei Province,Xingtai 054300,China)

机构地区：[1]河北农业大学,河北保定071000 [2]河北省核桃技术创新中心,河北邢台054300

出　　处：《食品科技》2025年第1期75-84,共10页Food Science and Technology

基　　金：“十四五”国家重点研发计划重点专项(2022YFD1600402);河北省创新能力提升计划项目(20527103D);河北省湿地保护与绿色发展协同创新中心项目开放基金项目(2023hbxczx1-11)。

摘　　要：蛋白作为核桃主要成分之一,对核桃精深加工有着重要的影响。文章对‘薄壳香’‘礼品二号’‘辽宁一号’‘绿岭’和‘清香’5种核桃的蛋白特性进行比较研究,为核桃加工专用品种的开发提供一定的理论依据。结果表明,5种核桃均包含分子质量在8~17 ku和19~25 ku的蛋白,‘薄壳香’‘礼品二号’‘清香’还存在26~32 ku的蛋白,而‘辽宁一号’和‘绿岭’的核桃蛋白在该范围内的蛋白较少甚至无法检出。蛋白的二级结构均以β-折叠和β-转角为主,且荧光发射峰波长均在340 nm左右,紫外吸收峰波长均在267 nm处,呈较为典型的谷蛋白特性。不过,热稳定性存在较大差异,‘辽宁一号’和‘礼品二号’的热稳定性较高,‘清香’核桃蛋白的热稳定性最低,但其胃蛋白酶和胰蛋白酶体外消化率最高。核桃蛋白在p H值为6时溶解性、乳化性和发泡性较差,在p H2~12间呈现先上升后下降的趋势。相比较而言,‘薄壳香’和‘礼品二号’的溶解性较好;蛋白乳化稳定性与乳化性变化趋势相似,泡沫稳定性与发泡性变化趋势相反。不同品种的核桃蛋白间其特性具有一定差异。Protein,as one of the main components of walnuts,has an important impact on the deep processing of walnuts.This study compared the characteristics of five walnut proteins:‘thin shell fragrance',‘gift No.2',‘Liaoning No.1',‘green ridge',and‘faint scent',providing a theoretical basis for the development of special walnut processing varieties.The results showed that all five types of walnuts contain proteins with molecular weights ranging from 8 ku to 17 ku and 19 ku to 25 ku,while the‘thin shell fragrance',‘gift No.2',and‘faint scent'still contain proteins with molecular weights ranging from 26 ku to 32 ku.However,the proteins in the‘Liaoning No.1'and‘green ridge'varieties of walnuts are relatively few or even undetectable in this range.The secondary structure of the proteins is mainlyβ-folding andβ-turning,and the fluorescence emission peak wavelength is around 340 nm,while the UV absorption peak wavelength is all at 267 nm,showing typical glutelin characteristics.However,there is a significant difference in thermal stability,with‘Liaoning No.1'and‘gift No.2'having higher thermal stability,while‘faint scent'walnut protein has the lowest thermal stability,but it has the highest in vitro digestibility by pepsin and trypsin.Walnut protein has poor solubility,emulsification,and foaming properties at pH 6,and shows a trend of first increasing and then decreasing between pH2 and pH12.Compared to other products,‘thin shell fragrance'and‘gift No.2'have better solubility.The change trend of protein emulsifying stability and emulsifying property is similar,while the change trend of foam stability and foaming property is opposite.There are certain differences in characteristics of walnut protein among different varieties.

关 键 词：核桃蛋白 分子质量 二级结构 热稳定性 溶解性 

分 类 号：TS201.21[轻工技术与工程—食品科学]