不同脱脂方法对椰子分离蛋白结构与理化性质影响研究

Effects of Different Oil Extraction Methods on Structure and Physicochemical Properties of Coconut Protein Isolate

研究不同脱脂方式对椰子分离蛋白性质的影响,从溶剂萃取椰子粕(SECPI),液压冷榨萃取椰子粕(CPCPI),超临界二氧化碳萃取椰子粕(SECPI(CO2))和亚临界丁烷萃取椰子粕(UCCPI)中分离蛋白质的物理化学和功能特性进行了调查.椰子蛋白具有三个主要条带(约25、35、55 ku),一个主要的X射线衍射峰(20.5°).UCCPI和SECPI(CO2)显示出相对更多的α-螺旋和β-折叠;SECPI中有较少β-片层,表明存在高度变性的蛋白质分子.在椰子分离蛋白中精氨酸含量最高,CPCPI中疏水性和带电荷的亲水性氨基酸含量最高.蛋白质溶解度在pH 4至5显示最小值,证实了椰子蛋白的等电点.UCCPI具有较高的吸水/吸油能力、荧光强度以及乳化能力.SECPI的发泡性能和表面疏水性高于其他脱脂方式所得蛋白.为脱脂椰子饼粕中蛋白的加工利用提供理论基础和科学依据.

In order to study the effects of different degreasing methods on the properties of coconut protein isolate,the physical,chemical and functional properties of protein separated from solvent extraction coconut meal(SECPI),hydraulic cold pressing extraction coconut meal(CPCPI),supercritical carbon dioxide extraction coconut meal(SECPI(CO 2))and subcritical butane extraction coconut meal(UCCPI)were investigated.Coconut protein had three major bands(about 25,35 and 55 ku)and a major X-ray diffraction peak(20.5°).UCCPI and SECPI(CO 2)showed moreα-helices andβ-folds.There were lessβ-lamellae in SECPI,indicating the presence of highly denatured protein molecules.Arginine content was the highest in coconut protein isolate,while hydrophobic and charged hydrophilic amino acids were the highest in CPCPI.The solubility of the protein showed a minimum value from pH 4 to pH 5,confirming the isoelectric point of coconut protein.UCCPI had high water/oil absorption capacity,fluorescence intensity and emulsifying capacity.The foaming property and surface hydrophobicity of SECPI were higher than those of proteins obtained by other degreasing methods.This study provided a theoretical basis and scientific basis for the processing and utilization of protein in defatted coconut cake meal.