Baseline microbial quality of sesame seeds before planting in Nigeria

Sesame seed production plays a vital role in Nigeria's economy, with the country ranking as Africa's second-largest and the world's fifth-largest producer. Despite remarkable growth from 149,401 tonnes in 2010 to 490,000 tonnes in 2020, making sesame Nigeria's second most exported crop after cocoa, small-scale farmers face significant challenges related to microbial contamination that result in border rejections and health concerns for local consumers. Aim This study aimed to assess the microbiological quality of sesame seeds from major producing states in Nigeria and identify the bacterial contaminants threatening food safety and export quality. Materials & methods Sesame samples were collected from Nasarawa and Niger states and subjected to microbiological analysis. Bacterial isolates were characterized using molecular techniques, and phylogenetic analysis was performed using Geneious Bioinformatics software to identify species-level relationships. Results Microbial counts ranged from 3.8 × 103 and 1.4 × 106 CFU/g in Nasarawa State samples and 7.0 × 102 and 6.3 × 105 CFU/g in Niger State samples. Molecular characterization revealed that Nasarawa samples contained 68.4% Enterobacter spp., 10.5% Pantoea dispersa, and 5.2% each of Pseudomonas juntendi, Cronobacter turicensis, Citrobacter sedlakii, and Klebsiella pneumoniae. Niger State samples yielded 44.4% Klebsiella spp. and Enterobacter spp., with 11.1% Acinetobacter baumannii. Significance This research contributes meaningfully to Nigeria's sesame production sector by highlighting critical gaps in food safety. The findings support three Sustainable Development Goals: reducing poverty (SDG 1), ensuring food security (SDG 2), and promoting good health and well-being (SDG 3). Improving food safety standards through better cultivation practices, personal hygiene, and proper handling protocols is essential for protecting public health and maintaining Nigeria's position in the global sesame market.