Submitted to: Journal of Cereal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/22/2004
Publication Date: 1/1/2005
Citation: Mohamed, A., Gordon, S.H., Harry O Kuru, R.E., Palmquist, D.E. 2005. Phospholipids and wheat gluten blends: interaction and kinetics. Journal of Cereal Science. 41:259-265. Interpretive Summary: Natural polymers interactions in different systems are not addressed adequately in the literature. The key to understanding these interactions is to understand the effect of these polymers on each other. The interaction between wheat protein and phospholipids is the determining factor that governs the final quality of baked products. It is also important in designating different types of flours for the appropriate uses. Since wheat protein is difficult to solublize, model phospholipid and gluten system were used to study their interaction. The physico-chemical properties of phospholipids are well-studied and reported in the literature. The study will benefit wheat producers in choosing the best type of phospholipids in their breeding programs. The results of this work will help wheat breeders to focus on the type of phospholipd that has more interaction with gluten protein and thus helps in the production of wheat flours for specific uses. The interaction between the two components was shown to be strong. That is consistent with the baking studies where phospholipids are found to increase bread loaf volume. The study reported the magnitude of the interaction in different conditions.
Technical Abstract: The determination of phospholipids (PL)-gluten interaction is critical for understanding the positive effect of PL on bread-loaf volume. A model system of lysophosphatidylcholine (LPC) and isolated gluten were used. The kinetics of the effect of gluten on the thermal properties of LPC was determined using DSC. Blends of PL and 3, 6, and 10% gluten were prepared. Five mg of blend were heated from 0ºC to 70ºC and cooled to 0ºC. Samples were heated at 3, 5, 7, 9, 11, 13, 15, 17, and 19ºC/min. The onset and peak temperatures or delta-H were recorded. The peak temperature was used for calculating the activation energy (Ea) and the Z value. The results showed that pure LPC vesicles formation transition was detectable by DSC in the presence of gluten. Gluten increased the activation energy of LPC during vesicles formation and disruption. The increase in gluten content from 3 to 6 and 10% had a slight effect on the activation energy value of LPC during vesicles disruption, whereas during formation a steady increase was noticed with higher gluten additions. Overall, the delta-H of the blends showed a decrease at higher heating rate. The change in the PL activation energy in the presence of gluten is indicative of a form of interaction.