Dielectric and physico-chemical techniques to evaluate the nutritional and quality characteristics of fino bread fortified with sunflower meal

Abstract

The fortification of fino bread with sunflower meal (SFM), as a source of protein and bioactive compounds, at the levels of 5, 10, 15, and 20% was investigated. The chemical composition, amino acid, phenolic profiles, and fiber fractions of SFM were determined. The prepared flour blends and fino bread samples were subjected to physico-chemical, dielectric, rheological, and organoleptic analyses. The obtained results showed that SFM is rich in amino acids, fibers and phenolic compounds. The rheological tests indicated that the fortification of wheat flour with SFM weakened the dough and reduced its elasticity and extensibility. Also, dielectric properties (DPs) gradually decreased as the SFM level increased. Fortified bread samples had a dense structure and dark brown color compared to the control sample. Photomicrographs of tested bread showed that SFM ruptured the gluten network and allowed starch granules to leach out. Bread samples were acceptable overall the organoleptic properties. These findings revealed the potential applications of SFM as a low-cost, and nutritious food ingredient to improve the nutritional value of bakery products. It also demonstrated the close dependencies between the physico-chemical and dielectric properties of raw materials and the quality characteristics of the final products.