Plant-based hydrocolloids are widely used in food, cosmetic, and pharmaceutical industries for their natural thickening and stabilizing properties. With rising demand for clean-label and functional ingredients, root and tuber hydrocolloids offer a sustainable solution. Hence, the study analysed the physicochemical properties of hydrocolloids extracted from the peels and flesh flour of specific root and tuber crops grown in south eastern Nigeria. Hydrocolloids were extracted from flour of Trifoliate yam (Dioscorea dumentorum), aerial yam (Dioscorea bulbifera), water yam (Dioscorea alata), white yam (Dioscorea rotundata), cocoyam (Colocasia esculenta), white and yellow fleshed sweet potato (Ipomoea batatas). The hydrocolloids were tested to determine the proximate composition, functional properties, gelation temperature, and pH levels. The findings revealed significant differences (P < 0.05). Moisture contents of flesh and peel samples ranged from 3.635% to 9.791%. Ash content from 0.60% to 6.10%. Crude fibre from 0.363 to 5.425 %, Carbohydrate from 82.294 % to 94. 406%. Functional properties results recorded highest values of 1.441(water yam peel) in swelling index, 4.200 % (water yam flesh) in foaming capacity, 78.805 % (yellow fleshed sweet potato flesh) in solubility, 2.205 (white yam peel) in oil absorption capacity, 2.505 (trifoliate yam flesh) in water absorption capacity, 69.310 % (cocoyam flesh) in emulsifying capacity, 75.615; 0.561; 0.766 (white fleshed sweet potato flesh) in freeze thawing stability, bulk density and tapped density. The highest values of gelation temperature and pH were observed in cocoyam peel (83 °C) and aerial yam peels (7.6). The potential of these hydrocolloids lies in their use as natural and sustainable ingredients in food formulations.
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.
Postharvest handling of fruits and vegetables in tropical regions faces significant challenges due to unpredictable weather. This review critically examines the application of conventional cold storage techniques in the postharvest management of tropical horticultural produce, considering the constraints that affect their performance and the environmental factors influencing the storage of tropical fruits and vegetables. Particular attention is given to the technical limitations of these systems when deployed under tropical conditions. The study systematically examined findings from peer-reviewed literature on various conventional cooling applications, offering a comprehensive overview of their performance and limitations. Furthermore, it explores the integration of solar powered refrigeration systems to enhance energy efficiency and promote technological innovation in off-grid cooling. Findings from this review underscore research gaps and highlight the need to develop advanced, climate resilient cold storage configurations tailored to the unique challenges of tropical environments. Specifically, integrating solar-powered refrigeration units with thermal energy storage (TES) compartments into conventional cooling systems for the storage of fruits and vegetables.
The evaluation of acute toxicity of three slow-release pelletised edible essential oils (SRPEEOs) extracted from clove (Syzygium aromaticum (L. Merr. and L. M. Perry), West African black pepper (WABP), (Piper guineense Schumach. and Thonn.) and Ginger (Zingiber officinale Roscoe) on the bean bruchid, Callosobruchus maculatus (F.) infesting cowpea, pigeon pea, Bambara groundnut, Lima and Soya beans. The research was conducted under laboratory conditions at the Faculty of Agriculture, Nasarawa State University, Keffi, Nigeria. Evaluation of the SRPEEOs on susceptibility and lethal concentration (LC50) was conducted using 0.25, 0.5, 0.75, and 1.0 g/5 g legumes. The treatments were replicated three (3) times, and the experiments were laid out in a complete randomised block design. Data analyses were conducted using Statistix 10, an analytical software package, in a two-way factorial analysis. All data were transformed before analysis. The results of the LC50 showed that WABP SRPEEO caused the highest mortality of bruchids (LC50: 1 g/5 g) compared to 0.25, 0.5, and 0.75 g/5 g for clove and ginger, respectively. The three SRPEEOs were very effective in conferring protection on the legume varieties against infestation by the bruchid and can also serve as an alternative to synthetic pesticides. However, SRPEEOs from WABP proved to be more effective and can thus repel colonisation of legumes by the cowpea seed bruchid.
Food is lost and wasted to varying extents across all stages of the food value chain and for all types of food, negatively impacting food security. In Nigeria, it has been revealed that a significant quantity of food is lost both before and after storage, with losses of up to 20-30% of all grains, 30-50% of roots and tubers, and a larger proportion of fruits and vegetables. Despite the Nigerian government's primary agricultural policy being to achieve food security and self sufficiency, the agricultural sector has steadily deteriorated over the years due to inadequate government attention. One of the primary causes of food insecurity, particularly in developing countries like Nigeria, is high postharvest losses and waste resulting from inadequate food processing and storage facilities, as well as negligence or a deliberate decision to discard food. This paper reviews the basic concept of food loss and waste, examines food security and the Nigerian situation, and discusses the challenges to food sufficiency, the implications and potential benefits of food loss, as well as some possible approaches to reducing food loss and waste in Nigeria. Thus, reducing food loss and waste is one of the leading global strategies for achieving a sustainable food future. Practical and cost-effective approaches could be implemented to attain mid-term gains once put into place. The review recommends the development of a food loss and waste measurement protocol and increased investments in reducing postharvest losses in Nigeria.
Postharvest losses significantly constrain the steady market supply of plantain; thus, bio-based preservatives are increasingly employed as sustainable alternatives to chemical agents for extending its shelf life. This study evaluated the effects of bio based coatings on plantain quality during a 15-day storage period. Mature green plantains were treated with gum arabic cinnamon extract coating (A), gum arabic clove extract coating (B), gum arabic bay leaf extract coating (C), gum arabic alone (D), untreated (E) and gum arabic shea butter coating(F). Treatment B recorded the highest weight loss of 28%. Although there was a decline in the moisture content of all treatments, treatment D showed optimal retention (65.660%). Treatments A (6.24) and F (6.153) maintained pH stability, while C and D exhibited acidification (4.87 and 5.25, respectively). Vitamin C levels increased across treatments (12.5–18.7 mg/100 g), although β-carotene degraded substantially. Treatment F demonstrated the highest starch content (58.228±0.002 mg/100 g) and potassium (8.54 mg/100 g). Treatments A, B, and C resulted in reduced bacterial populations, while treatments A and B achieved complete fungal inhibition. Treatment C recorded 33.33% decay incidence despite antimicrobial activity. Panelists rated F highest in colour (7.45), appearance (7.30), odour (6.90), texture (7.60), and general acceptability (7.75). Results demonstrate that gum arabic-shea butter coatings optimized overall quality and consumer acceptability, while cinnamon and clove formulations provided superior antimicrobial protection. These composite coatings offer sustainable alternatives for extending plantain shelf life under tropical conditions.
This study assesses the susceptibility of 31 legume varieties to Callosobruchus maculatus, a significant pest of these globally important, protein-rich staple crops, which are crucial for food security in sub-Saharan Africa. Field surveys and market visits across Northern Nigeria yielded 31 cowpea varieties, which were subsequently collected and evaluated for their susceptibility to Callosobruchus maculatus infestation. Physical attributes, including seed length, width, thickness, weight, density, volume, sphericity, porosity, surface area, and moisture content, were measured. The samples were then artificially infested with C. maculatus to assess resistance. Data analysis, including hierarchical data analysis, dendrogram clustering, histograms, and correlation analysis, was employed to reveal patterns and groupings of cowpea varieties based on physical traits. Distinct groupings of cowpea varieties emerged from the study, with smaller seed dimensions forming a cluster that included pigeon pea, Azuki beans, Achi Shiru, Farin Akidi, and Bakin Akidi. Another cluster, representing medium to large-seeded varieties, comprised 573-1-1, Kidney Beans, Shamjir Brown, and Zebra Beans. Overall, Farin Akidi exhibited the highest susceptibility to C. maculatus, followed by Agwugwu and Zebra Beans. In contrast, Lima Black, Lima Silver, and Kaki beans demonstrated the most substantial resistance. The study found negative correlations between pest resistance and seed traits, such as thickness, diameter, surface area, and weight, indicating their role in resistance. These findings provide valuable insights for breeders to develop more resilient cowpea varieties, thereby enhancing storage, adaptability, and genetic diversity, which supports global food security.
Onion (Allium cepa) derivatives contain bioactive compounds with antioxidant and antimicrobial properties that may improve product quality. This study evaluated the effects of onion juice (OJ) and onion chaff (OC) on the sensory, proximate, and microbial characteristics of smoked Clarias gariepinus to assess their performance in enhancing fish quality. Onions weighing 1kg were washed and blended to a paste, the pulp was transferred through a muslin cloth (1mm mesh-size) to obtain the juice by squeezing, leaving the chaff as a waste residue Thirty freshly harvested C. gariepinus (average weight 1kg) were divided into three groups of ten fish, each treated with OJ, OC, and untreated controls. All samples were smoked using a modified smoking kiln and stored at room temperature for eight weeks. Proximate composition, microbial characteristics and sensory attributes were analysed using standard procedures. Results indicated that OC-treated fish recorded higher proximate values, which differed significantly (p<0.05) from those of OJ-treated samples. Protein content decreased slightly across treatments, from 62.38% to 60.25% (OC), 60.09% to 58.05% (OJ), and 59.43% to 55.84% (control), while ash and moisture contents increased. Sensory evaluation revealed higher scores for OJ-treated fish in taste (7.90), appearance (8.05), aroma (7.80), texture (7.80), and overall acceptability (8.10) compared to OC-treated fish. Microbial organisms isolated showed varied characteristics. These findings suggest that onion derivatives enhance the sensory, nutritional, and microbial properties of smoked fish. Onion juice performed slightly better than onion chaff, suggesting its potential as a natural quality enhancer for smoked C. gariepinus.
Postharvest losses of fruits and vegetables remain high in Nigeria due to continued reliance on traditional sun drying and limited access to electricity-powered dryers. This study presents the modification and performance evaluation of the parabolic-shaped solar dryer (PSSD) integrated with a secondary heat source and an improved airflow system, designed to address the limitations of conventional dryers in maintaining optimal drying conditions during nighttime and cloudy weather. The modified dryer was compared with an existing, non-modified unit under no-load and load conditions, using 190 kg of tomatoes as test material. Temperature, relative humidity, drying rate, colour change and moisture content were monitored during evaluation. Und both conditions, the modified dryer achieved higher internal temperatures and lower relative humidity compared to the non-modified dryer and ambient air, resulting in improved drying efficiency and overall performance. Drying curves exhibited an initial warming-up phase followed by a falling-rate period, with a peak drying rate of 36.6 kg/day observed in the modified dryer. A safe final moisture content of 12.3% was achieved in 96 hours, compared with 120 hours and 13.9% (dry basis) in the non-modified dryer. Colour analysis revealed a decrease in L* (Lightness), a* (Redness), and b* (yellowness) for both systems; however, overall colour difference (ΔE) was consistently lower in the modified dryer (≈18.9) than in the non-modified dryer (≈23.2), indicating superior colour retention. The modification enhanced thermal performance, drying efficiency, and quality preservation, demonstrating its potential to reduce postharvest losses in tomatoes and promote sustainable drying technologies for smallholder farmers.
The overreliance on synthetic pesticides for stored-grain protection presents environmental and health concerns, highlighting the need for safer plant-based alternatives. This study evaluated the biopesticidal efficacy of onion peel, ginger, and alligator pepper formulations against storage fungi and insect pests (Sitophilus zeamais and Callosobruchus maculatus) infesting maize and cowpea. The plant materials were prepared as powders, aqueous extracts, and hexane oil extracts. Phytochemical screening and GC–MS profiling confirmed phenolics, alkaloids, flavonoids, glycosides, and tannins, with decanal (11.53%) in ginger, dodecadiene (7.01%) in onion peel, and octadecanoic acid (31.96%) in alligator pepper identified as major constituents. Antifungal activity was assessed via radial mycelial inhibition at five concentrations (0.2–1.0 g), while insect bioefficacy was evaluated at 1.0–3.0 g/50 g grain over 60 days. The aqueous extract of alligator pepper showed the strongest antifungal effect, restricting A. flavus and Penicillium spp. growth to 1.0 cm after 24 hours. Ginger aqueous extract at 3.0 g/50 g reduced maize grain damage and weight loss to 1.20 ± 0.20% and 1.33 ± 1.15%, compared with 38.42 ± 4.62% and 12.66 ± 8.33% in untreated controls (p < 0.05). Ginger oil extract at 3.0 g/50 g lowered cowpea damage (10.96 ± 1.00%) and weight loss (0.60 ± 0.20%) relative to controls (32.75 ± 8.86% and 7.78 ± 2.10%). Overall, ginger and alligator pepper extracts exhibited potent antifungal and insecticidal activity, demonstrating strong potential as sustainable, cost-effective botanical alternatives for integrated postharvest management of stored grains in tropical regions.
This study examined the insecticidal activity of onion and garlic peel extracts as a control method for sweet potato beetles, Cylas formicarius, infesting sweet potatoes after harvest. The primary objective of this study was to extract bioactive compounds from onion and garlic peels using a column chromatographic technique. The extracts were bioassayed against five C.formicarius adults in various concentrations: 0.01 g/0.25 kg, 0.02 g/0.25 kg, and 0.04 g/0.25 kg. Methanolic extract of onion peel being the most effective was subjected to isolation using column chromatography packed with silica gel of 60-120 mesh, employing a gradient elution technique. The elution started from 100% hexane and gradually incorporated 10% ethyl acetate until a 10% methanol in ethyl acetate solution. TLC was used to monitor similar fractions collected, and the combined fractions were then subjected to Prep-TLC until a pure compound, known as OM-15, was obtained. The results revealed that onion peel methanolic extract (OMH) caused 93.3% mortality 96 h postexposure. In contrast, garlic peel methanolic extract (GMH) caused 73.3% mortality, but hexane garlic peel extract caused 80% mortality 96 h postexposure, and the pure compound showed mortality of 60% on Cylas formicarius 96 h postexposure. It can be concluded that the methanolic extract of onion peels was more effective than the ethyl acetate and hexane extracts, and is not statistically different from the standard insecticide (cypermethrin) at P < 0.05 significant level. The extracts are eco-friendly and potent against Cylas formicarius, providing a scientific rationale for incorporating their development into biopesticides.
Pesticide misuse in Kano State poses a threat to both human health and agricultural trade. This is partly because grain handlers often lack training and overlook safer integrated pest management (IPM) practices. A purposive multi stage sampling technique was employed to select 120 pesticide handlers across 12 market commodity lines, and the collected data were analysed using SPSS and Microsoft Excel. Findings reveal critical gaps in pesticide handling at Dawanau Market, Kano. Although 64.2% use protective gear and 61.7% follow dosage instructions, 57.5% rarely use manuals, and 51.7% mix solutions incorrectly. Limited access to personal protective equipment, illiteracy, and poor exposure response highlighted the need for improved training and stricter regulation. Despite this, nearly half lacked formal training in pesticide use, pointing to a significant training gap. Approximately 81.7% of pesticides used were purchased from licensed vendors and stored properly; however, some handlers still stored them within living spaces, posing health risks. Preliminary awareness of first-aid procedures was evident, whereas understanding of safety label signals demonstrated variability. To address these, tailored training programs, supportive policy measures, and greater engagement in professional organisations are essential. Implementing these measures will help protect the health of handlers and the environment, while also boosting the quality and marketability of agricultural produce from Dawanau Market, Kano State.
Usage of improved fish processing methods appears to be relatively low compared to traditional methods. Hence, this research aimed to investigate the effect of the utilisation of Standard Fish Processing Practices (SFPP) on the livelihood status of fish processors in Delta and Edo States. Users and non-users of SFPP were sampled. Sampling of users involved a random selection of 70% from the trained 90 fish processors per state to give a sample size of 63 respondents per state and 126 users for the two states, while the snowballing technique was employed to select 63 non-users per state and 126 non-users for the two states to give a total sample size of 252 respondents for the research. Data used for this research were sourced using an interview schedule and analysed using descriptive statistics and a t-test. The results revealed that the majority (77.8%) of SFPP users had a high livelihood status, whereas a high percentage (63.5%) of non-users had a low livelihood status. Additionally, users of SFPP reported a better health status (19.95±3.29) compared to non-users, who had a poorer health status (52.50±8.15). Additionally, the majority (96.8%) of SFPP users were food secure, while 86.5% of non-users were food insecure. Vulnerability to poverty was low for 90.5% of SFPP users, whereas 80.0% of non-users showed high vulnerability to poverty. The study concluded that the usage of SFPP has significantly improved the livelihood status of fish processors in the study area. The study therefore recommends that agricultural extension agencies strengthen their efforts to disseminate SFPP to non-users.
In the present work, orange-coloured sweet potatoes (OCSP) and cream coloured skinned sweet potatoes (CCSP) were processed using the following methods: steaming (with or without peeling), roasting, boiling (with or without peeling), and frying. The functional and pasting properties, colour (L* a* b*∆E*), hydrolysis, and estimated glycemic indices (eGI), as well as the glycemic loads (GL) of the processed sweet potatoes, were studied. Results revealed that processing methods increased the swelling capacities, water absorption capacities, and bulk densities of sweet potato flours, with steaming (with or without peel) having the highest values. Processing methods reduced lightness (L*). They increased the yellowness (b*) of the sweet potato flours, while well visible colour differences (∆E*) were observed in the processed samples compared to the control (RAW – OC and RAW – CC). Processing reduced the HI, eGI, and GL of the sweet potatoes; the lowest values of these parameters were observed in the roasted samples. In this study, roasting was observed to provide significant nutritional benefits, making it a suitable dietary regimen for individuals who require low- to medium glycemic index (GI) foods.
Orange-fleshed sweet potatoes (OFSP) are considered one of the top sources of Provitamin A. It was incorporated into soybean cheese–like (awara) at varying proportions. Five (5) samples were produced using the following formulation ratio of soy bean and orange fleshed sweet potatoes (OFSP) (80:20, 60:40, 40:60, 20:80) and (100:0) as a control sample. The samples produced were evaluated for mineral content, anti-nutritional factor and sensory attribute, and the results were statistically analysed (ANOVA) for mean and standard deviation. The Anti nutritional factors and mineral composition of cheese-like (awara) samples showed a significant (p<0.05) difference among all the samples. The oxalate ranged from (2.86 – 4.65 mg/100g), phytate (0.30 – 1.28 mg/100g), tannin (103.58 – 125.78 mg/100g), and the trypsin inhibitor ranged from (7.59 – 18.92 mg/100g). The mineral content, Zn ranged from (1.42 – 2.54 mg/L), Fe (2.58 – 7.45 mg/L), Mg (1.66 – 3.92 mg/L), K (22.55 – 40.05 mg/L) and Na (6.36 – 9.28 mg/L). The sensory attribute of the cheese -like (awara) samples showed significant (P<0.05) difference among the samples, where the appearance ranged from (7.30 – 8.50), taste (6.20 – 8.50), mouth feel (4.50 – 8.30), texture (5.20 –7.90), general acceptability (6.50 – 8.20), aroma (5.00-8.20) and flavor (5.40 -7.50). In conclusion, the incorporation of orange fleshed sweet potatoes (OFSP) to soybean cheese-like (awara) increased phytochemical and mineral content of the samples appreciably. Samples D and E had the highest mean of all the parameters evaluated and were most preferred by the panelists.