Elhassan Mohammed S M, Oguntoyinbo Segun I, Taylor Janet, Taylor John R N
Institute for Food, Nutrition and Well-being and Department of Food Science, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa.
Institute for Food, Nutrition and Well-being and Department of Food Science, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa.
Food Chem. 2018 Jan 15;239:333-342. doi: 10.1016/j.foodchem.2017.06.114. Epub 2017 Jun 22.
Stable viscoelastic masses have been formed from kafirin in a mainly aqueous system. Kafirin was dissolved in glacial acetic acid (GAA) and simple coacervation was performed by rapid addition of 15°C water under low shear. Kafirin precipitated out as a network of hydrated fibrils which could be hand-kneaded into a viscoelastic mass. These could be formed from a very wide range of kafirins, including those where β- or γ-subclass expression was suppressed. Kafirin composition influenced the appearance of the masses but did not fundamentally affect stress-relaxation behaviour. Fresh kafirin masses exhibited similar elasticity and viscous flow balance to gluten. They maintained functionality when stored for several days at 10°C but their elastic component increased. FTIR showed that when kafirin was dissolved in GAA its α-helical conformation increased substantially. Dissociation of the kafirin molecules in GAA, assuming a α-helical conformation may have enhanced water binding, enabling viscoelastic mass formation.
在主要为水性的体系中，已由醇溶蛋白形成了稳定的粘弹性物质。将醇溶蛋白溶解于冰醋酸（GAA）中，并在低剪切力下通过快速加入15°C的水进行简单凝聚。醇溶蛋白沉淀为水合原纤维网络，可通过手工捏合形成粘弹性物质。这些物质可由非常广泛的醇溶蛋白形成，包括那些β-或γ-亚类表达受到抑制的醇溶蛋白。醇溶蛋白的组成影响了物质的外观，但并未从根本上影响应力松弛行为。新鲜的醇溶蛋白物质表现出与面筋相似的弹性和粘性流动平衡。它们在10°C下储存数天仍能保持功能，但弹性成分增加。傅里叶变换红外光谱（FTIR）表明，当醇溶蛋白溶解于GAA中时，其α-螺旋构象显著增加。假设为α-螺旋构象，醇溶蛋白分子在GAA中的解离可能增强了水的结合，从而能够形成粘弹性物质。
