Cereal Chem 48:150 - 158. | VIEW
Gelation Phenomena of Soybean Globulins. II. Protein-Water Miscible Solvent Interactions.
N. Catsimpoolas and E. W. Meyer. Copyright 1971 by the American Association of Cereal Chemists, Inc.
Dispersions of soybean globulins in water-alcohol and water-glycol mixtures form gels of higher apparent viscosity than do water dispersions. Rheological data indicate that the length of the aliphatic chain of the alcohol and the degree of branching affect the apparent viscosity of the gel significantly. The apparent viscosity increases with the length of the aliphatic chain. A branched-chain alcohol produces lower viscosity gels than does a linear-chain alcohol of the same number of carbon atoms. Glycols are less effective gel inducers, and the resulting apparent viscosities of the gels are much lower than those obtained with alcohols. The effect of the dielectric constant of the medium is very pronounced. However, for the same dielectric increment value, different values of apparent viscosity are produced depending on the alcohol or glycol. This is an additional indication that, besides the dielectric effect of the medium, the abilities of alcohols and glycols to unfold protein molecules may play an important role in the formation of the gel. Mixtures of water with acetone, dioxan, dimethyl formamide, and dimethyl sulfoxide had a marked enhancing effect on gel viscosity. However, only acetone and dioxan affected the progel viscosity, probably as a result of denaturation. Dimethyl formamide and dimethyl sulfoxide increased the gel viscosity probably through hydrogen bonding.