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.
As a possible substitute for synthetic insecticides, ethanolic extract of Gliricidia sepium seeds was used as a biopesticide to test its insecticidal activity against the infestation of Callosobruchus maculatus and Sitophilus zeamais in stored cowpea and maize. Four concentrations (0.1, 0.2, 0.3 and 0.4 mL of seed extract/200 g cowpea and maize) were employed in laboratory bioassays with cypermethrin as a standard check, to evaluate contact toxicity to adults, adult emergence and seed viability. Untreated grains were set up as a negative control. Treatments were in triplicate, and all experimental data were analysed using SPSS. Results showed the efficacy of gliricidia seed extract was dose-dependent. Adult S. zeamais and C. maculatus mortality increased with higher concentrations of the extract and more prolonged exposure periods. Gliricidia extract (0.4 mL/200 g) caused 75% mortality to C. maculatus 48 hours (2 days) after application, which was significantly different (p<0.05) from the 100% mortality caused by cypermethrin at the same period. Also, gliricidia extract (0.4 mL/200 g) caused 78.3% mortality to S. zeamais, significantly different from the 100% mortality caused by cypermethrin at 48 hours. Gliricidia extracts at concentrations 0.3 mL and 0.4 mL/200 g cowpea (37.0 % and 24.33% respectively) were better than the control 56.33% in reducing the number of emerged adult C. maculatus while extracts at concentrations 0.3 mL and 0.4 mL/200 g maize (22.33% and 27.67% respectively) were more effective than the control 64.3% in reducing the number of emerged adult S. seamais. The mean percentage germination of the cowpea and maize seeds in each treatment did not vary significantly (p > 0.05). The efficacy of this plant extract serves as scientific evidence to argue for employing the gliricidia extract as a botanical substitute for synthetic insecticides, which stakeholders commonly use to protect grains stored after harvest.