Abstract:The soluble dietary fiber (SDF) of oat bran with good physical and chemical properties prepared by microwave modification was added to fermented milk to study the effects of modified oat bran SDF on the number and stability of live lactic acid bacteria, pH value and acidity, coagulation time, texture, sensory quality, storage modulus, loss modulus and antioxidant activity of fermented milk. The results indicated that 4% addition of modified oat bran SDF could significantly increase the number of living lactic acid bacteria in fermented milk, improve the texture properties (P<0.05), favor the formation of gel network structure and shorten the coagulation time, however, excessive addition would affect the taste and stability of fermented milk. When the addition of modified oat bran SDF was 4%, the highest water holding capacity of fermented milk was up to 94.82%, and the hardness, viscosity, adhesiveness, elasticity and cohesion were the best. The scavenging ability of fermented milk to DPPH radical, hydroxyl radical and superoxide anion radical increased with the increase of modified oat bran SDF, and reached as high as 39.97%, 62.30% and 75.51%, respectively, significantly higher than that of the control group (P< 0.05). Modified oat bran SDF could significantly improve the quality and antioxidant activity of fermented milk. This study may provide a theoretical basis for the application of oat bran SDF and the development of functional fermented milk.
