Parveen Begum

Background: Phenolics and carotenoids are natural antioxidants, which provide health benefit and protect against degenerative chronic diseases. Utilization and identification of foods with high content of these received greater attention nowadays. Objective: The present study reports the total phenolics (TPC) and total carotenoids (TCC) contents of thirty-two selected unconventional vegetables growing in Bangladesh. In addition, they were also analyzed for their antioxidant potentials. Methods: Folin-Ciocalteu and acetone–petroleum ether extraction followed by spectrophotometric measurement were employed for TPC and TCC, respectively. The antioxidant capacities of the selected unconventional leafy vegetables were analyzed using DPPH and Trolox equivalent antioxidant capacity (TEAC) assays. Results: The results revealed that the TPC ranged from 82.41 mg GAE/100 g in Kiokro to 2711.05 mg GAE/100 g in Mrolapiong whereas the TCC values ranged from 43.05 µg/100 g in Fala to 12863.54 µg/100 g in Roktodrone. The study findings also revealed that the selected plant samples exhibited high antioxidant capacities. Mrolapiong demonstrated highest DPPH inhibition (91.31 %) and TEAC (485.55 μmol Trolox/g) value, than others. The antioxidant capacities were attributed to phenolic compounds as there exist a positive correlation between these two variables. Bioactive phytochemicals are widely distributed in these vegetables, although their amounts are varying among the different types of vegetables. Conclusion: The study results suggest that the vegetables analyzed may provide a possible source of dietary antioxidant and serve as material for functional foods. Therefore, their production and consumption must be encouraged in order to preserve biodiversity and prevent their extinction.

Dietary fibres are known to provide health benefit and protect against degenerative chronic diseases. Thus, the present study reports the total dietary fibre (TDF) content of sixty-nine selected ethnic and unconventional vegetables and fruits growing in Bangladesh. The samples were collected from different locations of Bangladesh and mixed together to ensure sample representativeness. Dietary fibre assay kit according to the AOAC method was utilized for the analysis of TDF in selected vegetables and fruits. In the ethnic varieties, the TDF content ranged from 1.02 ± 0.16 to 7.16 ± 0.16 g for leafy (LV), 0.18 ± 0.01 to 6.71 ± 0.49 g for non-leafy vegetables (NLV) and 1.21 ± 0.12 to 5.29 ± 0.20 g for fruits per 100 g edible portion (EP). In the unconventional items, it arrayed from 3.08 ± 0.34 g to 7.75 ± 0.13 g for LV and 1.02 ± 0.06 to 8.82 ± 0.40 g for NLV per 100 g EP. Among the analysed samples, the highest and lowest content of TDF was found in Orohordal and Mairabokong, respectively. The unconventional vegetables contained much higher content of TDF than the ethnics and the commonly consumed similar varieties. Data on TDF content in underutilized vegetables and fruits of Bangladesh is sparse. Thus, the finding of this study would fill up the data gap in the existing food composition table of Bangladesh and also would aware the people to take vegetables and fruits rich in fibres.