Formation of cereal protein disulfide-linked stable matrices by apigeninidin, a 3-deoxyanthocyanidin.

The food matrix is a factor affecting digestion rate of macronutrients, like starch. Sorghum protein networks surrounding starch have been associated with its comparatively low starch digestibility, though their formation mechanism is unclear. Since sorghums contain 3-deoxyanthocyanidins with redox property that could promote sulfhydryl-disulfide interchanges, we hypothesized that added apigeninidin (a 3-deoxyanthocyanidin) will form matrices in a non-matrix-forming cereal (corn). A model system using ovalbumin determined apigeninidin as a polymerizing agent. Starch digestion and microstructure of cereal porridges from yellow corn with and without added apigeninidin, commercial blue corn, and white sorghum were examined. Apigeninidin addition promoted protein matrices in yellow corn and attenuated initial starch digestion rate that was related to matrix formation rather than α-amylase inhibition. Blue corn with 3-deoxyanthocyanidins formed protein matrices with similar lower overall starch digestibility as sorghum. Promoting matrix formation in cereal-based foods with 3-deoxyanthocyanidins may be a strategy to modulate starch digestion rate.