Issue 2: Nigerian Journal of Postharvest Research
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Articles in This Issue
Evaluation of PICS and ZeroFly Hermetic Storage Bags for Preservation of Yam Chips and Flour Quality. Nigerian Journal of Post-Harvest Research, 3(2), 1-12.
Postharvest storage of yam products in traditional polypropylene bags often results in high losses due to insect infestation, microbial growth, and deterioration of physical and chemical qualities. This study evaluated two hermetic storage technologies, ZeroFly Hermetic (ZFH) and Purdue Improved Crop Storage (PICS) bags, for preserving yam chips and yam flour over six months. A completely randomized design with three treatments (PICS, ZFH, and control) was used to assess insect infestation, proximate composition, functional properties, pasting characteristics, microbial load, and sensory attributes. Results showed that ZFH bags maintained superior sensory quality (appearance: 7.80; overall acceptability: 7.40), whereas PICS bags provided the best protection against insect infestation. Moisture content remained stable in hermetic bags (13.51 ± 0.01% for chips; 16.05 ± 0.01% for flour), unlike the control, where significant increases were observed (15.06 ± 0.01% and 15.01 ± 0.01%, respectively). Peak viscosity declined during storage (from 5920–5938 RVU to 3689–4080 RVU), with greater reductions in the control. Microbial load was also highest in the control (2.3 × 10⁶ sfu/g in chips; 7.7 × 10⁴ sfu/g in flour), while hermetic storage effectively suppressed fungal growth. Insect emergence was substantial in control bags (T. castaneum: 87.33; A. fasciculatus: 65.33) but minimal in both hermetic options. Overall, hermetic storage significantly enhanced yam product preservation. ZFH bags are most suitable for maintaining sensory quality, while PICS bags excel in insect control. Storing yams as chips further improved moisture stability. Both technologies represent practical postharvest interventions for extending shelf life and safeguarding yam quality.
Evaluation of the Efficacy of Gliricidia sepium F. Seed Extract for Control of Insect Pests of Stored Maize and Cowpea. Nigerian Journal of Post-Harvest Research, 3(2), 13-18.
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.
Assessment of Proximate and Mineral Composition of Fermented Castor Bean, Melon, and African Locust Bean Seeds for Local Condiment Production. Nigerian Journal of Post Harvest Research, 3(2), 19 - 27.
Fermented castor bean, melon, and African locust bean seeds serve as a protein source in the diet of many Nigerians. Proximate and mineral composition changes during fermentation remain underexplored, particularly in comparative contexts. This study aimed to evaluate and compare these seeds' proximate and mineral compositions during controlled fermentation. Raw seeds were sourced from local markets and subjected to traditional fermentation processes for seven days in the laboratory. Proximate analysis was conducted using standard methods, while mineral contents were quantified using flame photometry after ashing. Analysis of Variance was used to determine a significant difference. Comparatively, at the end of the fermentation, the highest protein (39.96 ± 0.76%), fibre (8.03 ± 0.26%), ash (4.20 ± 0.00%), carbohydrate (13.10 ± 1.25%) and moisture (16.55 ± 0.79%) were recorded in fermented African locust bean seeds. The highest fat content was recorded in castor bean seeds (45.80 ± 0.62%). Comparative mineral composition at the end of fermentation showed that the highest zinc (3.31 ± 0.29 mg/ 100 g), magnesium (282.56 ± 2.03 mg/ 100 g), and calcium (220.00 ± 1.20 mg/ 100 g) were recorded in fermented African locust bean seeds. The highest potassium (1307.85 ± 5.87%) and sodium (55.93 ± 0.96 mg/ 100 g) contents were recorded in melon and castor bean seeds, respectively. This study suggests that fermentation enhances traditional condiments' nutritional and mineral value in West African cuisine. These findings support process optimisation, especially for African locust bean seed to inform dietary recommendations.
Preliminary Analysis of Post-Harvest Losses and Mitigation among ATASP – 1 Smallholder Farmers: Evidence from Selected Crop Value Chains in Nigeria. Nigerian Journal of Post-Harvest Research, 3(2), 28-37.
Post-harvest losses (PHL) remain a significant constraint to Nigeria's food security, farm profitability, and sustainable value chain development. This study examined the extent of PHL and adoption of mitigation technologies among smallholder beneficiaries of the Agricultural Transformation Agenda Support Program Phase 1 (ATASP-1). Funded by AfDB and launched in 2015, ATASP-1 operates in four staple crop processing zones across seven states, covering over 200 rural communities. Its objectives are to target rice, cassava, and sorghum to reduce poverty, create jobs, enhance food and nutrition security and raise incomes through sustainable agricultural growth and diversification. Using a multi-stage sampling technique, data were collected from 600 respondents (480 farmers and 120 processors) and analysed with descriptive statistics. Results revealed that ATASP-1 interventions reduced PHL in cassava (48.44%) and sorghum (29.93%) relative to national averages, while rice showed a moderate reduction (22.86%). Adoption of technologies was high, including metallic silos (85%), mud silos (90%), threshers (68%), drying slabs (84%), root choppers (91%) and safety/quality management systems (82%). Key constraints included high machinery costs (78%), limited accessibility (68%), poor infrastructure (59%), unreliable power supply (66%), high transport costs (81%) and high labour costs (73%). The study concludes that ATASP-1 substantially reduced PHL; sustaining and scaling these outcomes requires robust institutional frameworks, capacity building for farmers, and strategic rural infrastructure investment. Additionally, context-specific, zone-based interventions are essential to address heterogeneous constraints and optimise post-harvest loss reduction strategies across value chains.
Characterisation and Identification of Yeasts Associated with Indigenously Brewed Burukutu Drink Produced from Different Sorghum Varieties. Nigerian Journal of Post-Harvest Research, 3(2), 38-44.
Burukutu is a traditional African alcoholic beverage produced by spontaneous fermentation of malted red or white sorghum. Its unstandardised production often results in variability in microbial composition and product quality. This study investigated the microbial and fermentation profiles of burukutu prepared from both sorghum varieties, with emphasis on yeast population dynamics and acidification patterns. Laboratory-scale fermentation and analyses of locally brewed samples were conducted, with pH monitored over 48 hours. Yeasts were isolated and identified using morphological and microscopic features, alongside carbon assimilation profiles via the API 20C AUX system. Fermentation was characterised by a progressive decline in pH, confirming active microbial metabolism. Seven yeast species were identified: Saccharomyces carlsbergensis, Schizosaccharomyces pombe, Saccharomyces cerevisiae, Candida tropicalis, Candida auringiensis, Candida krusei, and Candida utilis. Among these, S. cerevisiae was predominant (36% of isolates), particularly in traditional samples. Its broad sugar assimilation and strong fermentative capacity underscore its central role in burukutu production. The dominant genera were Saccharomyces and Candida, consistent across both red and white sorghum fermentations. Comparative analysis revealed similar microbial and acidification profiles for the two sorghum varieties, indicating their equal suitability as raw materials. Notably, laboratory-prepared burukutu displayed more consistent yeast populations, suggesting that improved hygienic practices can enhance product quality and reduce microbial variability compared to traditional brewing.Overall, this study highlights the microbial ecology of burukutu fermentation, confirming the predominance of S. cerevisiae and underscoring the potential for process standardisation to improve quality and reproducibility in this indigenous beverage.
Postharvest Innovations for Food Security in Nigeria: Integrating Storage, Preservation, and Processing Technologies. Nigerian Journal of Post-Harvest Research, 3(2), 45-56.
Postharvest losses remain a critical challenge in Nigeria, affecting food security, economic development, and rural livelihoods. This study employs a qualitative systematic review methodology, following the Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) 2020 guidelines to ensure transparency and rigour. The review aims to examine technological innovations in postharvest storage, preservation, and processing relevant to Nigeria; analyse the roles of Agricultural Extension, Rural Sociology, and Biosystems Engineering in facilitating adoption and sustainability; evaluate the economic, socio-cultural, and institutional factors influencing postharvest innovation outcomes. A comprehensive literature search was conducted across scholarly databases and relevant institutional publications to draw insights from 35 sources with triangulation of peer-reviewed and grey literature published between 2015 and 2025 that investigated postharvest innovations in Nigeria. A thematic analysis identified four key categories: adoption through agricultural extension platforms, technological adaptation of postharvest tools, socio-cultural factors including gender disparities and trust networks, and institutional synergies and policy coherence. While innovations have improved shelf life and farmer incomes, challenges persist: poor rural infrastructure, gender disparities, fragmented extension services, and inconsistent policy support. Trust-building and community engagement were noted as critical to fostering technology uptake. The study recommends targeted investments in decentralised infrastructure, promotion of gender-inclusive innovation models, and coordinated public private partnerships to accelerate impact. In Nigeria, a revitalised extension system and coherent policy framework are essential to embed postharvest technologies into food systems. These measures will help transform the sector into a resilient and equitable pillar for national food security.
Detection of Serratia marcescens in Sliced Fruit Sold in Yakuba, Ilorin, Kwara State, Nigeria. Nigerian Journal of Post-Harvest Research, 3(2), 57-64.
Sliced fruits are widely consumed for their nutritional benefits; however, improper handling can lead to microbial contamination, posing public health risks. Serratia marcescens is an opportunistic pathogen capable of transmission through contaminated food. This research focused on detecting the presence of Serratia marcescens in sliced fruits sold in the Yakuba area of Ilorin. A total of 50 samples comprising watermelon (36%), pawpaw (34%), and pineapple (30%) were collected from six vendors. Isolation and identification of Serratia marcescens were performed using standard microbiological techniques. Antibiotic susceptibility testing was also conducted using the Kirby-Bauer disc diffusion method. Two isolates were identified as Serratia marcescens, accounting for 4% of all samples; both were found in watermelon, giving a fruit specific prevalence of 11.11% (2/18). No contamination was detected in pawpaw or pineapple samples. The contaminated samples originated exclusively from Vendor 3, resulting in a vendor-specific contamination rate of 22.22%. Antibiotic susceptibility testing showed that the isolates were 100% susceptible to ceftriaxone, trimethoprim-sulfamethoxazole, gentamicin, and tetracycline but showed complete resistance to ampicillin. In conclusion, the sliced fruit samples were contaminated with Serratia marcescens, and the isolates were resistant to one of the commonly used antibiotics.
Assessment of Insecticide Residues in Maize Grains from Major Markets in Ogbomoso, Nigeria. Nigerian Journal of Post-Harvest Research, 3(2), 65-72.
Maize (Zea mays L.) is a staple cereal crop of significant economic and nutritional importance worldwide. However, its production and postharvest storage are frequently compromised by infestations of insect pests, leading to yield and quality losses. The predominant method of pest control in maize storage involves the application of synthetic insecticides. This study evaluated the concentration of insecticide residues in maize grains sourced from major markets in Ogbomoso, Nigeria. Snowballing sampling technique was used to randomly select maize marketers from three markets: Odo-Oba, Iluju, and New Waso. Ten maize stores were sampled in each market. Composite samples representative of each market were prepared by combining 100 g subsamples from each store, with three replicates per market. Samples were transported to the laboratory, milled, and analyzed for pesticide residues using the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) extraction method, followed by gas chromatography – mass spectrometry (GC-MS) analysis on a Varian 3800/4000 instrument. Descriptive statistics and one-way analysis of variance (ANOVA) were performed using SAS version 9.2, with mean comparisons conducted using Duncan's Multiple Range Test at p < 0.05. Dichlorvos (2,2-dichlorovinyl dimethyl phosphate) was detected in all maize samples from three markets, ranging from 144.1 to 269.7 mg/kg, vastly exceeding the EU-MRL of 0.01 mg/kg. Such high residues pose severe health risks, including genotoxic, neurotoxic, reproductive, carcinogenic, respiratory, and dermal effects, potentially causing systemic toxicity or death. Urgent measures are needed to mitigate contamination and protect public health.