Melon seeds

What the name covers

Egusi is a food name, and the name is used for more than one cucurbit. Kew accepts Citrullus mucosospermus as the name of the melon whose seeds are sold as egusi, with Citrullus lanatus subsp. mucosospermus as a synonym. A USDA germplasm accession of this species carries egusi as its local name and was collected at Ibadan in Oyo State, Nigeria. That record describes one accession, not every seed sold under the name.

Other studies work with Cucumeropsis mannii, which Kew treats as a synonym of Melothria sphaerocarpa. Food and fermentation papers still use C. mannii. A 2025 review lists several conflicting names in the egusi literature and discusses disagreement over the crop's identity. For that reason this record treats melon seeds as an ingredient class. It does not assign a single species to every seed sold as egusi, and the botanical name a study prints stays attached to that study.

Ground for soup, fermented for ogiri

Egusi kernels are dried, hulled and ground for soup. That is a different product from ogiri-egusi, which is made by cooking and fermenting the seeds into a pungent seasoning. A 1990 review of traditional Nigerian fermented foods lists ogiri-egusi as a melon-seed condiment, distinct from ogiri made from fluted-pumpkin seeds or castor seeds, and describes household-scale natural fermentation.

Several experimental studies have tested the process. One used Cucumeropsis seeds, another compared Citrullus vulgaris, Citrullus colocynthis and Cucumeropsis mannii, and a third tested mixtures of melon and groundnut seed. Their results describe those experiments. None of them establishes one standard household recipe, and their substrates should not be treated as interchangeable.

Mould, aflatoxin and what the seeds can carry

A 2017 survey of raw melon seeds and ogiri bought in south-western Nigeria found bacteria and mycotoxins. Some melon and ogiri samples had detectable aflatoxins, and the authors recovered organisms they considered potentially pathogenic and raised hygiene concerns. The authors reported low overall mycotoxin levels in the lots they studied. Those results describe the sampled lots, not every seed or every batch.

A 1989 controlled experiment made ogiri from melon seed deliberately contaminated with Aspergillus flavus and measured how much aflatoxin fell during production. That reduction is a finding about that experiment. It is not a home method for rescuing mouldy or damaged seeds. Appearance and smell do not show that seeds are free of mycotoxins, and the sources reviewed give no validated household process, salt, time, temperature or pH limit for ogiri-egusi.

Choosing and handling the seeds

Seeds should not be fermented if they are mouldy, damaged or suspect. The sources reviewed do not give a grade system, a storage life or a shelf-life limit for raw melon seeds or for ogiri-egusi. Where a cook needs a practical check, the record can only say what the studies found, and that a fermented product's smell or taste does not prove it is safe.