Texturization of Peanut Proteins by Surface Film Formation 2. Changes in Lipid Distribution and Surface Tension Properties

Abstract

Changes in lipid distribution and surface tension during the formation of peanut protein-lipid film have been studied. Results from these measurements suggested that both polar and non-polar bonding of proteins to lipids occur during film formation. The film material contained high amounts of polyunsaturated fatty acids, and was found to be relatively stable to oxidative rancidity as measured by the thiobarbituric acid test. The effects of pH, protein concentration and added lipids on the surface tension of peanut protein suspension were investigated. An inverse relationship was observed between protein concentration and surface tension. As suspension pH was increased, the surface tension profile showed two prominent peaks; a major one at pH 4.5 and a minor one at pH 9.5. Adjustment of surface tension of the film forming suspension with surfactants of known HLB values showed that surface tension significantly (P ≤ 0.01) affected film formation.