# _Oncom_: A Nutritive Functional Fermented Food Made from Food Process Solid Residue
## 3 From Waste to a Nutritious Food
### Nutrition Composition of Oncom  
Each ingredient shows different characteristics and nutritional leftovers, which influence the nutrient quality of the _oncom_. Tofu dreg (_okara_), or ampas tahu in Indonesian, is an agro-industrial byproduct of soy products, including tofu and soymilk. It is estimated that seven metric tons of soymilk and two metric tons of _okara_ are generated from 1 metric ton of soybeans [35]. Tofu dreg (_okara_) is an insoluble component of the soybean shell, hull, or husk that can be white or yellowish [36]. Although it has undergone significant changes due to heating treatment applied during manufacturing, tofu dreg (_okara_) may contain protein similar to tofu and soy [3]. It has been established that tofu dreg (_okara_) still contains a significant amount of protein because not all the protein content is used up during tofu production [37]. Tofu dreg (_okara_) often has a protein content of up to 25.4-28.4% (dry basis), which makes it highly nutritious and has a high protein efficiency ratio, all of which indicate that it may be a source of vegetable protein for human consumption [38; 39]. This high protein content makes _oncom_ a valuable addition to a healthy diet. To support the production of fermented products, the amount of peanut press cake is crucial. For example, peanut processing generates a significant residue release in India in the form of peanut press cake. This cake is not wasted but is successfully utilized as a stable substrate for the growth of microorganisms that produce useful enzymes such as amylase, glucosidase, xylanase, and lipase. Its contribution to food production is invaluable and deserves recognition [20]. Other than _okara_ and peanut press cake, solid waste from tapioca is usually added to the mixture which is known as \"onggok\" [40]. _Ontggok_ still contains protein and carbohydrates, which makes it suitable for use as a food ingredient. _Ontggok_ improves the texture of _oncom_ by increasing the tenderness when added. The approximate composition of _oncom_'s ingredients can be seen in Table 3.  
The approximate configuration of tofu dreg (_okara_), peanut press cake, and tapioca solid waste as _oncom_ ingredients is represented in Table 3. Tapioca solid waste (72.49-85.99%) had the highest carbohydrate content, followed by tofu dreg (_okara_) (43.53%) and peanut press cake (35.30-35.87). Tofu dreg (_okara_) had a higher moisture content than peanut press cake. There was a notable difference in ash content. Peanut press cake had a higher protein content than the other two, while the fat content of tofu dreg (_okara_) was the highest [8; 40; 41; 42]. This is supported by the study of [PERSON] et al. [33], which discussed the effect of raw ingredients used in the _oncom_ itself. Higher ash content was seen in red _oncom_, although the addition of tapioca solid waste could make it lower. The use of peanut press cake and the soaking method in the process could reduce the ash content in black _oncom_. Whereas black _oncom_ had similar levels of fat, protein, and carbohydrates, red _oncom_ had over 90% of protein and carbs. Nearly 70% of black _oncom's_ ingredients were fat and protein, with peanut press cake serving as the primary raw material. The amount of fat and protein in peanut press cake was considerably higher [33]. Confirmed by the research of [PERSON] [26], black _oncom_ showed superior and higher nutritional value compared to red _oncom_. According to various studies, the chemical composition of _oncom_ is summarized in Table 4. Despite _Oncom_'s nutritional value varying wildly due to the influence of raw ingredients and the microbe's diversity, both _oncom_s show a promising nutrient composition.