Lupin (Lupinus spp.)-Fortified Bread: A Sustainable, Nutritionally, Functionally, and Technologically Valuable Solution for Bakery

Abstract

The purpose of this paper is to evaluate the nutritional, phytochemical, rheological, technological, and sensory properties of wheat flour dough and bread under a replacement of lupin flour at level 10, 20, and 30%. In this sense, the proximate composition, fatty acids profile, the content in total polyphenols content (TPC), antioxidant activity (AA), and flavonoids content (TFC) of lupin; wheat and flour composites; and the bread obtained from them were determined. The rheological properties of the dough using the Mixolab system were also evaluated. The results showed an improvement in the nutritional properties of bread with addition of lupin in the composite flour, especially in terms of proteins, lipids, and mineral substances and a significant increases of functional attributes, such as TPC, TFC, and AA, which recorded the highest values in the bread with 30% lupin flour (76.50 mg GAE/100 g, 8.54 mg QE/100 g, 54.98%). The decrease of lupin bread volume compared to wheat bread ranged between 0.69-7.37%, porosity between 6.92-35.26%, elasticity between 63-70%, and H/D between 3.17-19.05%. The rheological profile of the dough obtained with lupin flours indicates a moderate stability and proper kneading behavior. The sensory analysis was also performed in order to identify the consumer's acceptability regarding this type of bread. According to a 5-point hedonic scale, the most highly appreciated was the bread with 10% lupin flour, which obtained mean scores of 4.73 for general acceptability as compared with control bread (4.43).

Keywords: Mixolab; antioxidant activity; fatty acids; flavonoids; lupin flour; sensory score; wheat–lupin bread.

Figure 1

The technological chart-flow for obtaining bread.

Figure 2

Final products. WB, wheat bread; WBL10, lupin/wheat bread 10%; WBL20, lupin/wheat bread 20%; WBL30, lupin/wheat bread 30%.

Figure 3

Global values of the sensory evaluation (consumer acceptance) of bread with lupin: WB (control bread); WFL10 (10% lupin flour and 90% wheat flour); WFL20 (20% lupin flour and 80% wheat flour); and WFL30 (30% lupin flour and 70% wheat flour) by using a 5-point hedonic scale (n = 44). a,b,c—t-test has been used to compare the differences recorded between the samples for each characteristic assessed; data within the same column sharing different superscripts are significantly different (p < 0.05).