高酯果胶添加量对花生蛋白凝胶特性的影响Effect of high methoxyl pectin addition on gel properties of peanut protein

Abstract

为考察高酯果胶对花生蛋白凝胶特性的影响机制，以冷榨花生饼为原料，采用超声辅助法提取花生蛋白，并添加高酯果胶制备花生蛋白凝胶，以碱溶酸沉提取花生蛋白制备的凝胶为对照，研究高酯果胶添加量对超声辅助提取花生蛋白凝胶质构、持水性、流变特性和微观结构的影响。结果表明：添加高酯果胶可显著提高超声辅助提取花生蛋白凝胶的硬度、弹性、内聚性和持水性；高酯果胶添加量为1.0%时，超声辅助提取花生蛋白凝胶的硬度、弹性、内聚性和持水性以及储能模量（G′）和损耗模量（G″）均达到最大值，且除持水性外，均大于碱溶酸沉提取花生蛋白凝胶的；超声辅助提取花生蛋白与高酯果胶产生静电相互作用，在加热和冷藏条件下形成均匀致密的凝胶网络结构，对比碱溶酸沉提取花生蛋白凝胶，这种凝胶结构更为均匀致密。To investigate the effect of high methoxyl pectin (HMP) on the properties of peanut protein gels, peanut protein was extracted from cold-pressed peanut cake by ultrasound-assisted method(PPUAE)，then peanut protein gels was prepared by adding HMP.The effects of addition of HMP on texture, water holding capacity,rheological properties and microstructure of peanut protein obtained by PPUAE gel were studied with alkali soluble and acid precipitation extracted peanut protein gel as a control. The results showed that the addition of HMP could significantly increase the hardness, elasticity, cohesion and water holding capacity of the PPUAE gel. When the dosage of HMP was 1.0%, the hardness, elasticity, cohesion, water holding capacity, G′ and G″ of the PPUAE gel reached the maximum value, and were greater than those of the alkali soluble and acid precipitation extracted peanut protein gel except for water holding capacity. PPUAE produces electrostatic interactions with HMP, forming a uniform and dense gel network structure under heating and refrigeration conditions, which is more homogeneous and dense than the alkali soluble and acid precipitation extracted peanut protein gel.

Keywords

• 花生蛋白；超声辅助提取；高酯果胶；凝胶；流变特性；微观结构
• peanut protein; ultrasound-assisted extraction; high methoxyl pectin; gel; rheological property; microstructure