# _Oncom_: A Nutritive Functional Fermented Food Made from Food Process Solid Residue
## 6 A Potential Functional Food? Health-Promoting Properties of _Oncom_
### Oncom and Cholesterol Reduction  
_Oncom_, a \"plant-based food\", provides bioactive compounds like phytosterol, flavonoid and soluble fibre that can reduce blood cholesterol through a number of processes, such as promoting the elimination of bile acids and inhibiting intestinal absorption [140; 141]. Because they have structural similarities with cholesterol, phytosterols compete with it for intestinal absorption. Fermented soy products have been shown to reduce the serum concentrations of total cholesterol, low-density lipoproteins (LDLs), and triglycerides if consumed instead of animal protein [142]. According to [PERSON] et al., substituting plant-based meat for animal meat significantly reduces blood levels of LDL cholesterol [143]. Diets high in soy protein selectively reduced blood cholesterol in proportion to the degree of hypercholesterol [121]. Some bioactive compounds with cholesterol-lowering effects include phytosterol [9], flavonoids, and soluble fibre. Bioactive compounds in food can help lower cholesterol levels by inhibiting cholesterol absorption in the gut and increasing the excretion of bile acids [144]. Phytosterols (plant sterol) can promote cholesterol balance by reducing uptake, transport, metabolism, plasma concentration, and activation of the liver X receptor CPY7A1-mediated bile acids excretion pathway and influencing the transformation and metabolism of cholesterol [9]. Even though it is made from tofu dreg (_okara_), _oncom_ contains isoflavunes [120], particularly genistein, which has been linked to health benefits [123]. The presence of phytosterols, flavonoids, and soluble fibre, combined with the benefits of fermentation, positions _oncom_ as a valuable dietary option for individuals seeking to manage their cholesterol levels and reduce the risk of cardiovascular diseases. Future research should continue to explore the specific mechanisms by which these compounds interact and their potential long-term effects on cardiovascular health. Isoflavones, a class of flavonoids primarily found in soybeans, are recognized for their significant health benefits, particularly concerning lipid metabolism and cholesterol management. Isoflavones are mainly in the form of glycosides (daidzein and genistein) [121; 145]. Upon ingestion, these compounds undergo extensive metabolism, resulting in various metabolites that can be detected in biological fluids such as blood and urine [146]. Genistein and daidzein have cholesterolic effects by inhibiting hepatocyte apoB secretion through several mechanisms, including inhibition of cholesterol synthesis and esterification, inhibition of MTP activity and expression, and increase in LDL receptor expression [147]. Genistein was more efficient than daidzein at reducing blood triglycerides [148]. Daidzein reduced serum and hepatic cholesterol levels in female rats, but genistein did not; equal may be responsible for the hypocholesterolemomic effect [146]. The varying impacts of these isoflavings highlight the complexity of their mechanisms and the need for further research to elucidate their specific roles in cholesterol management. Daidzein and genistein levels in fresh _oncom_ were 6.6 and 3.1 mg/100 g wet weight, respectively [149]. These levels, while modest, contribute to the overall intake of isoflaves when _oncom_ is included in the diet. The incorporation of _oncom_ into a balanced diet may thus provide a source of these beneficial compounds, potentially aiding in cholesterol reduction. The cholesterol-lowering effects of soy isoflaves have been supported by various studies. For instance, a meta-analysis indicated that soy protein, particularly when combined with isoflaves, can lead to significant reductions in total cholesterol and LDL cholesterol levels [150]. However, some studies have suggested that the lipid-lowering effects may not be solely attributable to isoflaves, as other components of soy protein may also play a role [151].