Chemical, Physical and Sensory Properties on the Keeping Quality of Wheat-Groundnut Protein Concentrate Bread

Abstract

Background: Bread is a staple food and is consumed in large quantities because it is affordable, is an excellent source of nutrients and is available in a “ready to eat” form.
Objective: This study investigated the effect of groundnut protein concentrate (GPC) inclusion on the keeping quality of baked bread.
Methods: The bread samples were produced using straight dough method from blends of wheat flour and groundnut protein concentrate (%, w/w) at ratios 100:0, 95:5, 90:10, 85:15, and 80:20, with 100% wheat flour serving as the control sample. Subsequently, free fatty acids, proximate composition, minerals, physical and sensory properties as well as its shelf stability were determined using established methods.
Results: There was an increase in free fatty acid (FFA) across all the blends at day 1, 2 and 5. Highest free fatty acid were recorded in blend with 20% groundnut protein concentrate 7.83, 10.10 and 13.46 for day 1, 2 and 5 respectively. Highest protein content of 28.61% was recorded in blend with 20% groundnut protein concentrate. Significantly (P<0.05), a decrease in the loaf height and volume was observed in the samples as storage time increases. An increase in the loaf weight was observed for sample 90:10 and 85:15 on the fifth day of storage.
Conclusion: Sample with 20% groundnut protein concentrate revealed to maintain its wholesomeness in terms of sensory and other parameters measured during storage.

Keywords: wheat, bread, composite flour, groundnut, protein concentrate.