Abstract: Background and Objective: Plantain is known as a rich source of several bioactive components yet there are several local claims on how those bioactive components could be promoted by employing fermentation. This study was set to investigate the effect of fermentation on the phytochemical constituents; exploring Fourier Transformer Infrared (FTIR) spectroscopy and Ultraviolet-visible (UV) spectroscopy for possible detection of structural modifications on phytochemicals as well as to evaluate the impact of fermentation on the antioxidants potentials on unripe plantain fruit extract. Materials and Methods: Plantain fruit was sourced at a local market in Ede, Osun state, Nigeria, peeled, washed, homogenized with distilled water; the proximate, phytochemical, FTIR, UV and antioxidants analyses were investigated. Results: Fermentation significantly increased protein content while crude and soluble fibre fraction reduced significantly. All the selected phytochemical components increased significantly except for saponin and tannin that remain unaffected. The FTIR and UV analyses showed that the fermentation process resulted in the modification of some bioactive compounds (quercetin to quercetagetin, flavones and 2"-O-Xywsylvitexin) and formation of a class of phenolics (p-coumaric acid). Conclusion: This study showed the antioxidant potential of unripe M. paradisiaca could be greatly amplified through fermentation; hence the formation of a new compound could be the key behind these potentials.