Concentration dependent effects of dextran on the physical properties of acid milk gels.
The effect of dextran from Leuconostoc mesenteroides (DEX500), added to milk prior to acidification with glucono-δ-lactone (GDL) or Streptococcus thermophilus DSM20259, was studied with respect to polysaccharide concentration. The incorporation of 5-30 g/kg DEX500 significantly affected gelation behavior. Increasing DEX500 concentrations resulted in a linear increase of gel stiffness (GDL gels: R(2)=0.96; microbial acidification: R(2)=0.94; P<0.05) and 30 g/kg DEX500 resulted in a 2-fold higher stiffness compared to gels without polysaccharide. The respective stirred gels depicted a significant reduction in syneresis, which decreased from 30.4% (0 g/kg DEX500) to 22.0% (30 g/kg DEX500) for chemically acidified gels after 1 d of storage. Physical characteristics of DEX500 in aqueous solution were helpful to explain its behavior in the complex system milk.
Institute of Food Technology and Bioprocess Engineering, Technische Universität Dresden, Bergstrasse 120, 01062 Dresden, Germany. Electronic address: susann.mende@tu-dresden.de.
Susann
S
Mende
Michaela
M
Peter
Karin
K
Bartels
Tingting
T
Dong
Harald
H
Rohm
Doris
D
Jaros
D000818:Animals; D003911:Dextrans / Q000737:chemistry*; D005285:Fermentation; D005782:Gels; D005942:Gluconates / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007783:Lactones / Q000737:chemistry*; D007934:Leuconostoc / Q000737:chemistry*; D008892:Milk / Q000737:chemistry*; D044367:Phase Transition; D012212:Rheology; D055672:Static Electricity; D048249:Streptococcus thermophilus / Q000502:physiology; D013696:Temperature; D014783:Viscosity
D003911:Dextrans; D005782:Gels; D005942:Gluconates; D007783:Lactones; C010730:beta-glucono-1,5-lactone
Acidified milk; Dextran; Gelation; Rheology; Syneresis