碧根果蛋白pH调节法制备及其加工特性研究  

Preparation and processing characteristics of pecan protein by pH-shifting method

作　　者：陈紫薇 潘利华[1,2] 陈银娣 孙美 罗水忠 郑志[1,2] CHEN Ziwei;PAN Lihua;CHEN Yindi;SUN Mei;LUO Shuizhong;ZHENG Zhi(School of Food and Biological Engineering,Hefei University of Technology,Hefei 230009,China;Anhui Province Key Laboratory of Agricultural Products Modern Processing,Hefei 230009,China;ChaCha Food Co.Ltd.,Hefei 230031,China)

机构地区：[1]合肥工业大学食品与生物工程学院,安徽合肥230009 [2]农产品现代加工安徽省重点实验室,安徽合肥230009 [3]洽洽食品股份有限公司,安徽合肥230031

出　　处：《食品与发酵工业》2024年第23期242-247,共6页Food and Fermentation Industries

基　　金：国家重点研发计划专项(2023YFD2100400);2024年安徽省科技创新攻坚计划(202423110050025);广东省农产品加工重点实验室开放课题资助(202106)。

摘　　要：以低温压榨碧根果粕为原料,探讨了pH调节法制备碧根果酸溶蛋白(acid-soluble protein,AP)和碱溶蛋白(alkali-soluble protein,BP)的最适溶出pH和最适沉淀pH,并对AP和BP的理化性质及其加工特性进行了研究。结果显示,AP在pH 2.0时溶出率最大,为4.79%;在pH 12时沉淀回收率最大,达70.09%。BP在pH 12.0时,溶出率最大,达到53.01%;在pH 3时沉淀回收率最大,达99.88%。AP和BP的得率分别为24.15 g/100 g和1.53 g/100 g碧根果粕。SDS-PAGE分析显示,AP亚基集中在22 kDa以下,BP亚基分子质量分别为20、39、45 kDa;AP游离巯基和二硫键含量为16.61和1.40μmol/g,BP的游离巯基和二硫键含量分别为14.58和1.34μmol/g;AP和BP分别在pH 3和pH 11时溶解性最佳,溶解度分别为76.77%和94.75%;AP的持水性高于BP,持油则低于BP;BP在pH 3~11起泡性、乳化性均高于AP。扫描电镜结果显示,AP结构呈现不规则的聚集状态,BP呈表面光滑的大片状结构。研究结果表明,AP适用于牛奶等酸性饮料等食品,而BP则适用于冰淇淋、面包、蛋糕等对起泡性质有较高要求的食品。The acid-soluble protein(AP)and alkali-soluble protein(BP)from cold-pressed pecan cake were separated using the pH-shifting method,and the functional properties of AP and BP were analyzed.The optimal conditions for the extraction of AP and BP from pecan cake were determined based on protein dissolution rate and precipitation recovery.The pH of 2.0 and 12.0 were found to be the optimal dissolution conditions of AP and BP,resulting in dissolution rates of 4.79%and 53.01%,respectively.For precipitation recovery,the optimal conditions of AP and BP were pH 12 and pH 3,with protein recovery rates of 70.09%and 99.88%,respectively.The molecular weights of AP were distributed below 22 kDa,while those of BP subunits were aggregated at 20 kDa,39 kDa,and 45 kDa,based on the results of SDS-PAGE.The contents of free sulfhydryl groups and disulfide bonds of AP were 16.6 and 1.40μmol/g and the contents of free sulfhydryl groups and disulfide bonds of BP were 14.58 and 1.34μmol/g.AP had the highest solubility of 76.77%at pH 3,while BP had the highest solubility of 94.75%at pH 11.AP retained more water than BP,while BP had better oil holding capacity.Additionally,the foaming and emulsifying capacities of BP were higher than those of AP.The scanning electron microscope results showed that BP exhibited a large lamellar structure with a smooth surface,while AP displayed an irregular shape with honeycombs and holes on the surface.The results of the study illustrated that AP was suitable for application in acidic food products such as milk and acidic beverages,while BP was recommended for the ice-cream,bread,and cakes which require higher foaming properties.

关 键 词：pH调节法 碧根果粕 分离蛋白 功能特性 

分 类 号：TS229[轻工技术与工程—粮食、油脂及植物蛋白工程]