Author Archives: aajbb

Mucuna seeds, once largely neglected, are gradually being incorporated into the diets of some communities in Benin because of their high protein content. However, their utilization is constrained by the presence of antinutritional compounds, particularly L-Dopa, which may pose health risks if not adequately reduced during processing. Traditional processors employ various processing methods to detoxify the seeds, but the safety of the resulting foods prepared from different Mucuna varieties has not been fully established. This study aimed to evaluate the L-Dopa and tannin contents of the major traditional Mucuna-based foods in Benin in relation to their processing methods. A total of 84 processors and consumers were interviewed to document Mucuna processing practices and consumption patterns. Subsequently, 10 Mucuna-based food samples were collected and analysed for L-Dopa using the USP–NF 2022, Issue 1 method, while total tannins were determined using the Folin–Ciocalteu method. The results showed that Mucuna processing and consumption were infrequent, occurring mainly once per quarter, with Ata, Afitin, and Abobo being the principal traditional products. Raw white- and black-seeded Mucuna contained 4.6% and 5.0% L-Dopa, respectively. Following processing, L-Dopa contents decreased markedly, ranging from 0.002% to 3.0% depending on the product. Abobo and Afitin contained residual L-Dopa levels below the 1.0% safety threshold, whereas Ata exceeded this limit. Tannin contents in processed products ranged from 0.033 to 0.841 mg tannic acid equivalents/g, indicating substantial reductions following soaking, cooking with water renewal, roasting, and fermentation. Overall, traditional processing methods effectively ensured the safety of Abobo and Afitin, whereas further optimization is required for Ata. These findings provide evidence-based guidance for improving traditional Mucuna processing practices and support the safe utilization of this underutilized legume to enhance dietary diversification and household food security in Benin and similar settings.

Cabbage (Brassica oleracea var. capitata) is one of the major winter vegetables grown in Bangladesh, recognized for its dietary value and economic importance. During November 2023, cabbage leaves exhibiting typical leaf spot symptoms were collected from the Bangladesh Agricultural Research Institute (BARI), Gazipur, to identify the associated pathogen. The infected leaves showed dark brown to black necrotic lesions with concentric rings characteristic of Alternaria leaf spot. The pathogen was isolated on Potato Dextrose Agar (PDA) and purified using a single-conidium isolation technique. Morphological characterization revealed colony and conidial features consistent with Alternaria alternata. To confirm the pathogen identity, molecular characterization was performed using the internal transcribed spacer (ITS) region of rDNA. Amplification with ITS1/ITS4 primers generated a 510 bp fragment, and the resulting sequence was deposited in GenBank under accession number OP585635. Comparison of the obtained sequence against the GenBank database revealed a high degree of homology (99%) with previously deposited A. alternata sequences. The phylogenetic tree also placed the isolate in the same evolutionary group as A. alternata, with 88% bootstrap support. Species-specific PCR using A. alternata-specific primers produced the expected 184 bp amplicon, providing additional confirmation of species identity. Pathogenicity was evaluated using a detached-leaf assay. Leaves inoculated with the fungal isolate exhibited characteristic disease symptoms comparable to those recorded in naturally infected plants, while no symptoms were detected on the control leaves. Following symptom development, the fungus was recovered from infected tissues and its identity was verified using an A. alternata-specific PCR assay, satisfying the requirements of Koch’s postulates. The combined evidence obtained from cultural and microscopic observations, ITS-rDNA sequencing, phylogenetic inference, species-specific molecular detection, and pathogenicity assessment demonstrated that A. alternata was responsible for the leaf spot symptoms observed on cabbage. To our knowledge, this study constitutes the first molecularly confirmed record of A. alternata infecting cabbage in Bangladesh. The information generated will support future disease monitoring efforts and contribute to the formulation of appropriate management practices for sustainable cabbage production.

Abstract not available

Vegetables, including broccoli (Brassica oleracea var. botrytis), are important components of the human diet due to their high nutritional value. However, insect pests pose a major challenge to broccoli production, and pesticides are widely applied to maintain crop quality and yield. In Bangladesh, indiscriminate pesticide use often leads to residues in vegetables, posing risks to human health and the environment. This study aimed to determine the pre-harvest interval of commonly used insecticides in broccoli and compare residue levels with the maximum residue limits (MRLs) established by the European Union. Broccoli was sprayed with recommended doses of lambda-cyhalothrin, dimethoate, and chlorpyrifos plus cypermethrin at 1 mL/L, and acephate at 2 g/L, across four supervised field trials. Samples were collected at 0, 1, 3, 5, 7, 9, 11, 13, 15, and 17 days after spray (DAS), and residues were analyzed by gas chromatography using a flame thermionic detector for organophosphorus insecticides and an electron capture detector for pyrethroids. Residue levels exceeded the EU-MRL up to 11 DAS for lambda-cyhalothrin, 13 DAS for chlorpyrifos plus cypermethrin and acephate, and 15 DAS for dimethoate. The PHI was determined as 13 DAS for lambda-cyhalothrin, 15 DAS for chlorpyrifos plus cypermethrin and acephate, and 17 DAS for dimethoate. These findings provide valuable guidance for farmers on safe pesticide use and support the production of safe vegetables for consumers.

Lettuce (Lactuca sativa L.) is a nutrient-rich leafy vegetable commonly raw consumed and grown in soilless systems that often rely on expensive chemical fertilizers. Exploring sustainable nutrient alternatives like salt industry by-products (SIB) can reduce input costs and environmental impact. This study aimed to evaluate the effect of SIB as a partial nutrient source on lettuce growth, yield, and nutritional quality in a soilless culture system. The experiment was conducted at the Central Laboratory of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh from September 2014 to March 2015. The base nutrient solution contained NO₃-N (17.05 meqL⁻¹), P (7.86 meqL⁻¹), K (8.94 meqL⁻¹), Ca (9.95 meqL⁻¹), Mg (6.0 meqL⁻¹), S (6.0 meqL⁻¹), and micronutrients Fe (3 ppm), B (0.5 ppm) , Zn (0.1 ppm) , Cu (0.03 ppm), Mo (0.025 ppm), and Mn (1 ppm). Treatments included 0 (control), 0.5 and 0.75 mlL⁻¹ SIB. The control produced the highest plant height, leaf number, breadth, length, and fresh weight, while 0.75 mlL⁻¹ SIB-treated plants exhibited the lowest growth but the highest ascorbic acid (157.61 mg/100 g) and beta-carotene (3.21 mg/100 g) contents. The 0.5 mL L⁻¹ SIB treatment resulted in moderate yield with balanced nutritional quality, indicating comparable leaf area, relative growth rate, and net assimilation rate to the control. It can therefore be concluded that 0.5 mL L⁻¹ SIB may serve as a sustainable nutrient supplement in hydroponic lettuce production. This finding emphasizes the potential of utilizing salt industry by-products as an eco-friendly and cost-effective nutrient source in soilless cultivation systems.

Demand for ripe fruit, especially mango, is increasing around the world due to its nutrients and delicious taste attributes. But commercial handling of mangoes fruits meets challenges due to irregular fruit ripening. A practical solution to tackle this issue could be the application of external ethylene to the physiologically matured mango fruit for its climacteric nature of respiration and ethylene rate. This study aimed to figure out the optimum ethylene concentration for mature mango uniform ripening and its efficacy on the fruit quality with shelf life. Ethylene works as a catalyst to accelerate ripening processing of climacteric fruits. Therefore, exogenous concentration liquid ethylene was applied on ‘BARI Aam-2’ mangoes at low-cost fruit ripening chamber where ethylene gas was released from a portable ethylene generator (Catalytic Generators, USA) into a ripening chamber. Physiologically matured mango (BARI Aam-2) was collected from Bagha at Rajshahi and uniform with defectless were randomly selected for experimentation. To ensure uniform ripening, ethylene was applied per liter capacity for specific durations such as 1 min (50 ppm), 2 min (100 ppm), and 3 min (150 ppm) with concentrations verified using a gas analyzer (IAQ22080143). Among them, mango treated with 100 ppm to 150 ppm ethylene accelerated the highest peak of respiration indicating accelerated metabolic activity, while membrane permeability increased over time. Fruit firmness declined across all treatments, with similar softening levels by Day 8. The total soluble solids (TSS) levels peaked at 100 ppm and 150 ppm treatments, enhancing sweetness and carbohydrate metabolism. The study concludes that 100 ppm ethylene optimally balances ripening, sweetness, and nutrient preservation while minimizing weight loss. This application of optimum exogenous ethylene effectively regulated the ripening process of physiologically matured mango, with moderate concentration promoting desirable ripening as per the market demand and maintaining postharvest quality which ensure the produce safe for consumption.