Bioactive compounds, antioxidant activity and physical characteristics of wheat-prickly pear and banana biscuits

• Published in: Heliyon 2019-10, Vol.5 (10), p.e02479-e02479, Article e02479
• Main Authors: Mahloko, Lesetja M., Silungwe, Henry, Mashau, Mpho E., Kgatla, Tsietsie E.
• Format: Article
• Language: English
• Subjects: Antioxidant activity; antioxidants; banana peels; bananas; Biscuits; color; Composite flour; flavonoids; Flour; Food analysis; Food science; hardness; oils; Opuntia; ovens; pears; Total phenolic content; wheat; wheat flour
• ISSN: 2405-8440; 2405-8440
• DOI: 10.1016/j.heliyon.2019.e02479

In this study, banana and prickly peel flours were oven dried at 60 °C overnight and incorporated at a maximum of 4% (w/w) levels in wheat flour for biscuit production. Wheat, banana, prickly pear and composite flours and biscuits were evaluated for functional, bioactive compounds and antioxidant activities as well as physical properties. Functional properties analysis indicated that banana peel flour (BPF) and prickly pear flours (PPF) showed higher water holding capacity and oil holding capacity, ranging from 2.63 to 4.29 g/ml and from 1.15 to 2.0 g/ml, respectively. Total phenolic content ranged from 10.87 to 17.35 mg/g and from 11.21 to 11,44 mg/g in composite flour blends and total phenolic contents in biscuits improved from 11.365 mg/g to 11.81 mg/g with 4% BPF incorporation; and decrease to 10.92 mg/g with 4% PPF incorporation and 10.79 mg/g with 4% BPF and PPF, respectively. Total flavonoid content ranged from 15.78 to 23.19 mg/g in PPF and BPF, respectively and from 0.75 to 13.31 mg/g for control and composite flours. Moreover, results for Total flavonoid content of biscuits ranged from 17.0 to 33.74 mg/g. DPPH values ranged from 3.29 to 30.0% in flours and 8.12–9.69% in biscuits. FRAP values ranged from 0.57 to 1.51 mg/g for flours and 0.59–0.71 mg/g for biscuits. With regards to colour, incorporation of BPF and PPF resulted in decrease of L* value and b* values for composite flours and decreases in parameter L* and b* values for formulated biscuits. Spread ratio of biscuits showed an increase with addition of BPF and PPF, while diameter and height of biscuits decreased. Hardness of the biscuits increased with addition of BPF and PPF. Results suggest that by incorporating BPF and PPF, it is possible to enhance functional properties, colour parameters, antioxidant activity of the flours and biscuits.