不同提取方法对甜荞蛋白理化特性的影响

Effects of Different Extraction Methods on Physicochemical Properties of Common Buckwheat Protein

采用碱溶酸沉法、酶法、盐浸法3种方法提取甜荞籽粒蛋白质,研究不同提取方法对甜荞粗蛋白以及各蛋白组分(清蛋白、醇溶蛋白、球蛋白、谷蛋白)含量、蛋白颗粒形态、溶解性、泡沫特性、乳化特性、持水性、持油性、热变性等理化特性的影响。结果表明,3种方法提取的甜荞蛋白质理化性质有一定差异。碱溶酸沉法和酶法提取的蛋白质颗粒比盐浸法提取的蛋白质的颗粒大且有鳞片状突起,而盐浸法提取的蛋白表面平整光滑。碱溶酸沉法提取的蛋白质含量最高,且溶解度和乳化性能最佳;酶法制得的甜荞蛋白中醇溶蛋白和谷蛋白含量最高,持油性、持水性及热焓值(ΔH)较高,且显著高于碱溶酸沉法和盐浸法,具有更好的热稳定性;盐浸法制得的清蛋白含量最高,泡沫特性最好。综合比较发现,碱溶酸沉法和酶法是适宜食品加工的甜荞蛋白质提取方法。

The common buckwheat protein was extracted by three methods:alkali-soluble acid precipitation extraction,enzymatic extraction,salt leaching extraction.The effects of different extraction methods on physical and chemical properties of common buckwheat protein,such as the powder,morphology,crude protein,albumin,gliadin,globulin,gluten,solubility,foaming capacity and stability,emulsifying capacity and stability,water holding capacity,fat absorption capacities,thermal denaturation were studied.The results showed that there were some differences in physical and chemical properties of common buckwheat protein extracted by three methods.The scaly protruding and big particles in the common buckwheat protein granules of alkali-soluble acid precipitation extraction and enzymatic extraction were higher than that of the salt leaching extraction.The crude protein,solubility and emulsifying capacity and stability of common buckwheat protein of alkali-soluble acid precipitation extraction were significantly higher than that of the others methods.The prolamin and glutent content,water holding and fat absorption capacities,enthalpy(ΔH)values of the common buckwheat protein of enzymatic extraction were the highest,and there was a significant difference with behind two extraction methods.It had better thermal stability.The albumin,foaming capacity and stability of the common buckwheat protein of salt leaching extraction were significantly higher than that of the others methods.In summary,alkali-soluble acid precipitation extraction and enzymatic extraction were the appropriate method of extraction of common buckwheat protein.