Roudsari Mehrnaz, Nakamura Akihiro, Smith Alexandra, Corredig Milena
Department of Food Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
J Agric Food Chem. 2006 Feb 22;54(4):1434-41. doi: 10.1021/jf051369g.
The stability of emulsions prepared with soy protein isolates was investigated as a function of pH in the presence of two negatively charged polysaccharides: high methoxyl pectin (HMP) and soy soluble polysaccharide (SSPS). Both polysaccharides are composed of a backbone which contains galacturonic acid but, when added to soy protein isolate-stabilized emulsions, SSPS showed a different behavior than that of HMP. At neutral pH and above a critical concentration of stabilizer (0.05%), HMP caused flocculation of the emulsion droplets via a depletion mechanism. On the other hand, the emulsions containing a similar amount of SSPS did not show creaming or flocculation. At acidic pH (<4.0) the addition of pectin caused extensive droplet aggregation, while no aggregation was observed with the addition of SSPS. The differences in the stabilization behavior between the two polysaccharides can be attributed to their differences in charge, neutral sugars side chains, and molecular weight.
研究了在两种带负电荷的多糖（高甲氧基果胶（HMP）和大豆可溶性多糖（SSPS））存在下，用大豆分离蛋白制备的乳液稳定性与pH值的关系。两种多糖均由含有半乳糖醛酸的主链组成，但当添加到大豆分离蛋白稳定的乳液中时，SSPS表现出与HMP不同的行为。在中性pH值及高于稳定剂临界浓度（0.05%）时，HMP通过耗尽机制导致乳液滴絮凝。另一方面，含有相似量SSPS的乳液未出现分层或絮凝现象。在酸性pH值（<4.0）下，添加果胶会导致大量液滴聚集，而添加SSPS时未观察到聚集现象。两种多糖在稳定行为上的差异可归因于它们在电荷、中性糖侧链和分子量方面的差异。
