The PHYTOCHEMICAL COMPOSITION, PHYSICAL AND SENSORY PROPERTIES OF BREAD SUPPLEMENTED WITH FERMENTED SWEET ORANGE PEEL FLOUR: Quality of bread supplemented with fermented sweet orange peel flour

Objective: The objective of the study was to determine the phytochemical composition, physical and sensory properties of bread supplemented with fermented sweet orange peel flour. Methods: Sweet orange fruits were washed, peeled and the peels were sliced into thin slices, sun dried to constant weight, milled, and sieved. The sweet orange peel flour was fermented (5:12, flour:water) for 4 days at ambient temperature, oven dried at 60°C to constant weight, milled, and sieved. The fermented and unfermented sweet orange peel flours were analyzed for the phytochemical composition. The sweet orange peel flour was blended with wheat flour in the ratio of 90:10 (wheat:peel flour). The flour blends were used to produce bread which were evaluated for the phytochemical composition, physical and sensory properties. The 100% wheat flour bread and the bread containing unfermented sweet orange peel flour served as controls. Results: The phytates, oxalates, flavonoids, tannins, alkaloids, and saponins contents of the unfermented sweet orange peel flour were 0.37%, 0.21%,0.27%, 0.8%, 0.96%, and 0.15%, respectively. The fermented sweet orange peel flour contained 0.1% phytates, 0.10% oxalates, 0.56% flavonoids, 0.11% tannins, 0.78% alkaloids, and 0.09% saponins. All the bread containing sweet orange peel flours had higher amounts of phytates, oxalates, flavonoids, tannins, alkaloids, and saponins than the 100% wheat flour bread. The levels of the phytochemicals in the bread except flavonoids decreased with the period of fermentation of the sweet orange peel flour. The fermentation of the sweet orange peel flour did not significantly (p>0.05) affect the weight and height of the bread containing fermented sweet orange peel flour. However, the volume, specific volume, and oven spring of the bread increased with increase in the fermentation period of the sweet orange peel flour. The scores for taste, flavor, color, texture, and overll acceptability increased significantly with an increase in the period of fermentation of the peel flour. However, the bread containing sweet orange peel flours was rated significantly (p<0.05) lower than the 100 % wheat flour bread for all the sensory attributes evaluated. Conclusion: Supplementation of bread with fermented sweet orange peel flour improved the physical and sensory properties of the bread but decreased the phytochemical contents except flavonoids