# Oil Press-Cakes and Meals Valorization through Circular Economy Approaches: A Review
## 4 Anti-Nutritional Factors
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Types** & **Oilcakes** & **Effect** & **Reference** \\ \hline Sinapine & Rapeseed/Canola & dark color; undesirable taste, & [51,94,110] \\  & Rapeseed/Canola, & indigestibility; lower nutritional value & [51,94,110] \\  & Sesame, Sunflower, & decrease mineral availability and & \\ Phytic acid & Soybean, Groundnut, & absorption and digestion of proteins & [90,94,113] \\  & Hempseed & and starch & \\  & Soybean, Sesame, & asstringency, inhibit protein & \\ Tarnis & Sunflower, Groundnut, & adsorption, produce amino & [90,94,113] \\  & Rapeseed, Hempseed & acid imbalance & \\ Saponins & Soybean, Sunflower, & hemolysis, interference in bile acids, & \\  & Hempseed & lipid-soluble vitamins, cholesterol and & [90,94] \\  & Glucosinolates & Rapeseed/Canola, & reduce feed intake, impaired thyroid & [10,94,113] \\ Cyanogenic glycosides & Hempseed, Flaxseed & function, liver enlargement & \\  & Hempseed, Flaxseed & pyridoxine (B\({}_{6}\)) deficiency & \\  & & protein indigestibility and alter their & \\ Chlorogenic acid & Sunflower & organoleptic properties, storage life & [94,101] \\  & & and stability in food systems & \\ Trypsin inhibitors & Soybean, Sunflower, & & \\ Sesame, Groundnut, & Reduce protein digestibility & [90,94,112,113] \\  & Hempseed, Flaxseed & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Main antinutritional factors. Heat treatment can remove or reduce effectively cyanogenic glycosides, proteases, trypsin inhibitors, glucosinolates, and phytic acid (the last one was reduced by 43%). The extraction of protein isolates is another method useful to eliminating the anti-nutritive factors, due to the high pH used [109; 111]. Extrusion, solvent extraction and biological, thermal, or microwave treatment are various methods used to reduce or remove cyanogenic glycosides. The heat hydrolyzed the latter in hydrogen cyanide, which is then evaporated [114]. Phytates and tannin levels in sesame oil cake can be reduced by fermentation with _Lactobacillus acidophilus_, after which it can be used as feed in the diets of _Labvo rolita_[67]. Tannins from groundnut oil cake can be removed through solid-state fermentation (SSF) with the help of _Pichia kudriavzevii_, a process that also enhances its chemical properties [115]. The same process with _Rhizopus oligosporus_ DSM 1964 and ATCC 64063 was performed for flaxseed press-cake to reduce phytate by 48% and 33% respectively, and which enhances the bioavailability of calcium, magnesium, and phosphor by 14%, 3.3% and 4% [116]. Methods for glucosinolates removal in canola are: extraction of protein based on protein micellar mass formation with minimal loss of proteins (ultrafiltration because the toxic compounds have low molecular weight than proteins), heat treatment (reduction of 94% and improved flavor and palatability), use of enzyme (pectinase, protease, hemicellulose), application of organic solvent (ethanol, methanol, and acetone). During the traditional extraction of proteins, the amount can be reduced due to the dilution process during washing [22; 110].