乳清蛋白与海藻酸钠复合物凝胶特性的影响因素

Influence Factors of Characteristic of Whey Protein and Alginate Sodium Compound Gel

海藻酸钠与乳清蛋白复合物凝胶具有较好的包埋性,可用于活性物质的微胶囊化,具有广泛的应用价值。本研究采用热处理方式对乳清蛋白与海藻酸钠进行交联,并对影响乳清蛋白与多糖凝胶特性的因素进行研究,结果表明:在10%乳清蛋白溶液中添加2.0%的海藻酸钠,80℃加热30 min,乳清蛋白与海藻酸钠复合物凝胶质构特性较好;当海藻酸钠添加量为1.5%时持水性较好。复合物凝胶特性明显优于乳清蛋白凝胶和海藻酸钠凝胶,说明二者结合能够提高凝胶的性状,达到改性的目的。p H值越高质构特性和持水性越差。添加甘油使凝胶质构特性显著下降,其持水性虽很高,但甘油对海藻酸钠与乳清蛋白的交联阻碍很大。当K+浓度在50~200 mmol/L之间时,凝胶的硬度和黏度随K+浓度的增大而增大,而凝聚性和粘性指数在100 mmol/L达到最大值。

The wall material with better embedding capability, which is used alginate sodium to modify whey pro-rein, can be used to microencapsulate some active substances, thus it has a wide application. This paper used heat treatment to crosslink whey protein and alginate sodium, and studied for the factors which could influence the properties of whey and polysaccharide gel. As the result of experiments, the texture characteristics of WP＋SA gel were best at the addition of 10% WP and 2.0% SA when heated at 80 ~C for 30 min, while the water-holding capacity was best at 1.5% SA. The two properties of separately heated WP and SA were neither better than WP＋SA gel, indicating that the experi- ment achieved the propose of cross-linking two biopolymers. The two properties decreased with the increasing pH value. Ahhough the addition of glycerol let gel＇s water-holding capacity increase, the texture characteristics descended. And glycerol heavily blocked the cross linking between WP and SA. With the concentration of K＋ increasing, the firmness and consistency improved, while the coherence and index of viscosity were both best at 100 mmol/L.