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This study investigated the antioxidant and antimicrobial effects of the peel, rind, pulp and seeds of C. lanatus (watermelon) as well as their respective phytochemical composition. The antioxidant effect was investigated using the DPPH and ABTS assay whereas the antimicrobial activity was evaluated using the well diffusion and broth dilution methods. The results revealed that the peel possessed the highest antioxidant activity whereas the pulp demonstrated the lowest. The peels demonstrated the highest antimicrobial effect, which was followed by the seed and then the rind. The pulp, however, demonstrated the least antimicrobial activity. A strong correlation was observed between total phenolic contents and biological activity. The peels were found to possess the highest content of total phenolics (0.087±0.002 mgGAE/g), which was followed by the seed (0.042±0.003 mgGAE/g) and the rind (0.026±0.003 mgGAE/g). The pulp did not only demonstrate the lowest antioxidant and antimicrobial activities but also had the lowest phenolic content (0.010±0.001 mgGAE/g). The peel and the seed show the presence of flavonoids whereas alkaloids and free reducing sugars were present in all parts of the watermelon fruit. From the results of the current study, it can, therefore, be concluded that among the various parts of the watermelon fruit, the peel has the highest antioxidant and antimicrobial activity whereas the pulp has the least. The peels and seeds are not only potent in their antioxidant and antimicrobial effects but also possess appreciable levels of phenolic compounds relative to the other parts.

The aim of the study was to determine the antioxidant capacity in fresh Lemongrass (LGF), dried Lemongrass (LGD), processed teabags; Lipton black tea (LBT), Super black tea (SBT), Lipton green Tea(LGT) and Zesta green tea (ZGT) and the impact of time and temperature on them. The total phenol and flavonoid contents were determined by Folin Ciocalteu and aluminum chloride techniques respectively. The antioxidant capacity was determined by ABTS and DPPH assays. The effect of temperature regulation and the leach time duration of the various teas were also determined. ZGT recorded the highest antioxidant capacity of 47% and 56% for both DPPH and ABTS respectively for methanol extracts. SBT had the highest phenol content (74.99 mgGAE/100 ml) and LBT had the highest flavonoid (102.40 mgCE/100 ml). The antioxidant capacities for the different temperature regulations for all the samples ranged from 4% to 99% and 8% to 85% for ABTS and DPPH respectively. A similar trend of 2% to 87% and 3% to 66% was also seen for the time regulations for ABTS and DPPH respectively. There was a significant difference in antioxidant capacity between the tea samples for leach time regulation; however, there was no significant difference for the temperature regulations. In conclusion, the antioxidant capacity, total phenol and total flavonoid content of the tea infusion were impacted by variations in duration of extraction and temperature of exposure. The extraction time at 5 min recorded the highest antioxidant capacity for temperature regulation for most of the tea infusions between 25 and 80°C. In respect of the samples, SBT had the highest TPC and TFC whiles Camellia sinensis showed higher antioxidant activity over Lemongrass. Further research on the effect of time and temperature on local tea brands is warranted to ensure that appropriate choices are made towards the consumption of tea to boost wellness.