Oncom: A Nutritive Functional Fermented Food Made from Food Process Solid Residue

Food security is one of the critical issues in facing the world food crisis. Utilizing food processing residue waste to make nutritious and healthy functional foods should follow a double-merit approach in facing the world food crisis. Oncom, an overlooked traditional fermented product based on local wisdom, might be an example of potential sustainable food to overcome hunger and support the circular economy programme. This review attempts to portray the existence and role of oncom based on a systematic study of hundreds of reports from different angles, mainly focusing on its processing, the microbes involved, its sensory characteristics, nutritional benefits, and promising bioactivities. Oncom can be produced by various raw materials such as tofu dreg (okara), peanut press cake, and tapioca solid waste, involving various microbes, mainly Neurospora sp. or Rhizopus sp., and various processing steps. The products show promising nutritional values. In terms of sensory characteristics, oncom is sensory-friendly due to its umami dominance. Many bioactivity capacities have been reported, including antioxidants, lowering cholesterol effect, and cardiovascular disease prevention, although some findings are still only preliminary. Undoubtedly, oncom has the potential to be developed as a future functional food with standardized quality and reliable bioefficacy. This kind of solid fermented product, based on agricultural residue wastes, is worthy of further development worldwide with full scientific support to create more reliable functional foods with a modern touch to achieve zero hunger.