# _Oncom_: A Nutritive Functional Fermented Food Made from Food Process Solid Residue
## 5 Sensory Characteristics of _Oncom_: _Oncom_ as an Alternative to Meat  
As mentioned, increasing consumer interest in products of plant origin and non-waste causes food producers to develop various food products from the agri-food industry; waste must be allowed [5; 14]. _Oncom_ is a good example, both the fermented tofu dreg (_okara_), called red _oncom_[95], and black _oncom_ from fermented peanut press cake (FPPC), waste from the production of peanut oil [14]. Both types of _oncom_ are not just valuable sources of protein [14; 95]; they also hold the potential to revolutionize the food industry as a substitute for meat. Black _oncom_, for instance, is already being consumed in Indonesia as a cheap, protein-rich meat alternative [20]. It is eaten as an indigenous dish usually served deep-fried or cooked with native dishes [20]. Another way to prepare _oncom_ is to roast it, cut it into pieces, and serve it with ginger sauce, or cook it in boiling water and season it with salt and sugar [96]. The versatility of _oncom_ in various culinary applications further underscores its potential as a meat substitute. One of the most exciting properties of both fermented products (_oncom_) is their umami flavour [23]. This unique taste, often described as savoury and rich, results from the biochemical transformations during fermentation. The fact that _oncom_ retains its umami flavour even after frying [20; 96] makes it a promising ingredient for many dishes (Table 6), especially as a plant-based alternative to meat. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Sensory Characteristics** & **Red _Oncom_** & **Black _Oncom_** \\ \hline Colour & \begin{tabular}{c} Shiny orange colour, reddish \\ yellow, salmon pink, \\ golden yellow, brownish \\ yellow, blackish brown, \\ orange, red \\ \end{tabular} & \begin{tabular}{c} Greyish black colour, black \\ with white hyphae, greyish \\ black, ash grey \\ \end{tabular} \\ \hline Colour & \begin{tabular}{c} Minced meat when cooked, \\ beany, musty, fermented, sour \\ \end{tabular} & \begin{tabular}{c} Pleasant fruity odour, musty, \\ nutty aroma \\ \end{tabular} \\ \hline Taste and flavour & \begin{tabular}{c} Savoury/umami, bland, bitter, \\ sourness, lower intensity of \\ umami taste than in black \\ _oncom_ \\ \end{tabular} & \begin{tabular}{c} Umami taste, higher intensity \\ of umami taste than in red \\ _oncom_ \\ \end{tabular} \\ \hline Aftertaste & \
\begin{tabular}{c} Bitterness, sourness, and \\ tartness \\ \end{tabular} &
\begin{tabular}{c} Bitterness \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Sensory characteristics of red and black _oncom_[3; 20; 22; 23; 33; 96; 97]. The unami fractions obtained by ultrafiltration and chromatography of red _oncom_ and black _oncom_, which are responsible for the unami taste, were studied by [PERSON] and colleagues [23]. Fractions of red _oncom_ with a molecular weight (MW) less than 3000 Da and black _oncom_ with a molecular weight (MW) greater than 3000 Da obtained during ultrafiltration were characterized by an intense umami taste. Using gel filtration chromatography combined with flavour dilution analysis for further fractionation identified unami fractions in which free glutamic acid, free phenylalanine, and peptides containing their amino acid residues were present [23]. The unami flavour intensity of the water-soluble extract (WSE) of black _oncom_ was twice as high (DF = 1.024) as that of red _oncom_ (DF = 512). The intensity of the umami taste was determined by soluble proteins, which were twice as numerous in black _oncom_ as in red _oncom_[23]. In addition to its umami taste, the flavour of black _oncom_ is also described by some authors as slightly alcoholic and fruity [96], which depends on the fermentation process and mould activity. It also has a pleasant fruity odour [20]. On the other hand, when fried, _oncom_ takes on the flavour of minced meat [20] or an almond flavour [96].