Dietary fibre rich inner and outer bracts of culinary banana flower -

Dietary fibre rich inner and outer bracts of culinary banana flower

The present study endeavoured to evaluate the nutritional, phytochemical and functional properties of outer and inner bracts of culinary banana flower which is a by-product of banana production. Both outer and inner bracts were found to be rich in dietary fibre (61.13 and 66.22%, respectively) along with other chemical compositions including proximate, minerals, and antioxidant-rich phenolics both free and bound. In addition, the functional properties including glucose dialysis retardation index (GDRI) of outer and inner bracts were also studied. The outer and inner bracts exhibited total polyphenols 7.56 and 9.44 mg phenols/g dry sample, respectively. The polyphenol profile by HPLC, revealed the presence of significant amount of free and bound phenolics in both outer and inner bracts. Functional properties of these dietary fibres-rich fractions of culinary banana flower exhibited lower bulk density, higher water-holding capacity, oil-holding capacity, and water-swelling capacity in outer and inner bracts than cellulose. The outer and inner bracts showed relatively higher GDRI compared to control and cellulose. The results revealed that both the outer and inner bracts of culinary banana flower are rich source of dietary fibre along with high antioxidant activity and could be one of the promising functional ingredients for low calorie and high-fibre food product.

Preparation of sample

Culinary banana flowers were washed immediately after collection and outer and inner bracts were separated and dried separately at 40 °C in a tray drier. Samples were ground, packed in air tight container and stored at room temperature (25 ± 5 °C) until further analysis. Analysed total polyphenol content and antioxidant activity. HPLC analysis was carried out for phenolic extract.

Conclusion

The present study revealed that both outer and inner bracts are potential sources of DF along with other nutrients and phytochemicals. Both outer and inner bracts contained significant amount of bound polyphenols and could be considered as antioxidant rich DF. Moreover, better functional properties (e.g. WHC, OHC, WSC and GDRI) evidenced that outer and inner bracts are superior to cellulose and many other DF rich sources. All-inclusive results evinced that the outer bracts along with the inner bracts constitute a good source of DF associated with polyphenols and its excellent functional properties render it more suitable source of DF. The results of the present investigation has the credentials to support that both the outer and inner bracts of culinary banana flower could be commercially exploited for extraction of DF coupled with high antioxidant activity and has the potential as functional food to promote and maintain human health.

Reference:

Begum, Y.A. and Deka, S.C., 2019. Chemical profiling and functional properties of dietary fibre rich inner and outer bracts of culinary banana flower. Journal of food science and technology, 56(12), pp.5298-5308.