Maize is highly vulnerable to infestation by the maize weevil (Sitophilus zeamais). The widespread use of synthetic insecticides in pest management has raised significant environmental and health concerns, necessitating the exploration of sustainable, plant-based alternatives. This study evaluated the insecticidal, repellent, and emergence inhibition of methanolic extracts from Aframomum melegueta, Pterocelastrus tricuspidatus, and Bryophyllum pinnatum against Sitophilus zeamais in stored maize. Standard phytochemical and antioxidant analytical techniques were used to assess the insecticidal efficacy of the plant extracts. Phytochemical screening revealed that A. melegueta possessed the highest phenols (10.65 mg/100g) and tannins (3.83 mg/100g) contents, while P. tricuspidatus recorded the highest flavonoids (3.90 mg/100g), saponins (1.44 mg/100g), and cardiac glycosides (8.31 mg/100g) levels. B. pinnatum showed the highest alkaloid content (7.85 mg/100g). Antioxidant activity assessed by DPPH radical scavenging showed strong activity across all extracts, with A. melegueta exhibiting the highest activity (74.13%). Bioassay results demonstrated a concentration and time-dependent mortality in S. zeamais, with B. pinnatum showing the highest mortality of 83.33% at 5% after 36 h, while P. tricuspidatus achieved 76.67% at 2%. Repellency assays showed that all extracts significantly deterred insect presence, with P. tricuspidatus exhibiting superior repellency even at lower concentrations. Additionally, adult emergence inhibition was most pronounced at 10%, with P. tricuspidatus and B. pinnatum recording 0.00% emergence within 12 and 24 hs, respectively. These findings highlight the potential of these plant extracts as eco-friendly insecticides. Their rich phytochemical composition, potent antioxidant properties, and strong bioactivity support their application in postharvest grain protection and integrated pest management (IPM) strategies.
African bush mango has fleshy mesocarp (pulp) rich in vitamins, essential minerals, and phytochemicals. This essential part is usually wasted due to a lack of knowledge of the processing and storage methods. This study aimed to determine the quality evaluation (proximate compositions, microbial loads, and sensory evaluation) of fleshy mesocarp and stored chips of African bush mango. African bush mango fruits were obtained from a farmer in Effraya, Etung Local Government Area, Cross River State. The fruits were sorted, and the hard ones were washed and used for this experiment. The exocarp of the fruits was slightly peeled, and the fleshy pulps were then sliced thinly. The sliced pulps were dried using a multi-crop dryer (at an average temperature of 56.61±1.577 °C). The proximate composition and the sensory evaluation of the fresh pulp and chips (dried pulp) were evaluated. Then, the chips were stored for 6 weeks, and the proximate and microbial analyses were conducted using standard laboratory methods (at 3-week intervals). Except the moisture content, all other proximate contents —ash, fat, fibre, protein, and carbohydrate—showed higher values in the chips (dried pulp) compared to the fresh pulp, with respective values of 3.20%, 1.10%, 10.50%, 5.20%, and 72.10% in the chips, as opposed to 0.89%, 0.65%, 1.65%, 2.43%, and 13.83% in the fresh pulp. The values of sensory scores obtained for both samples were more than 6. Furthermore, the retention of proximate nutrients and observing low microbial loads in the chips during storage suggest that the product remains safe and suitable for consumption during the off-season. Therefore, the chips could be maximally utilised to reduce wastage.