The stabilizing behaviour of soybean soluble polysaccharide and pectin in acidified milk beverages英文电子书.pdf

ARTICLE IN PRESS International Dairy Journal 16 (2006) 361–369 /locate/idairyj The stabilizing behaviour of soybean soluble polysaccharide and pectin in acidified milk beverages a,b b b a, Akihiro Nakamura , Ryuji Yoshida , Hirokazu Maeda , Milena Corredig aDepartment of Food Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1 bFood Science Research Institute, Tsukuba RD Center, Fuji Oil Co. Ltd., 4-3 Kinunodai, Yawara-mura, Tsukuba-gun, Ibaraki 300-2497, Japan Received 9 September 2004; accepted 8 January 2005 Abstract The mechanisms of stabilization of soybean soluble polysaccharide (SSPS) and high methoxyl pectin (HMP) in acidified milk drinks were studied focusing on the differences in behaviour between the two polysaccharides. The changes in casein micelles size during acidification with glucono-d-lactone or by direct acidification were measured using light scattering. When HMP was added to skim milk before acidification, pectin adsorbed on the surface of the casein micelles via electrostatic interactions and prevented casein aggregation. Results suggested that adsorption of pectin occurred from the beginning of acidification and somewhat affected the rearrangement of casein micelles in the pH range between 5.8 and 5.0. On the other hand, SSPS, at concentrations up to 2% (w/w), did not interact with caseins at pH 44.6. At pH o4.2 SSPS showed better stabilizing properties than HMP. In addition, between pH 4.2 and 3.2, SS