July 21/Madrid, Spain/Food Business Week -- According to recent research from Madrid, Spain, "The combined effect of high hydrostatic pressure (HHP) and controlled temperature on total (TDF), soluble dietary fiber (SDF) content, and its associated hydration properties were assayed in okara, a rich-in-insoluble dietary fiber residue from the soydrink- and tofu-making process of soybean. TDF in starting unprocessed okara was 45.7%, and its SDF to TDF ratio was 4.6."
"When dry, hydrated and autoclaved okara samples, were subjected to HHP-treatment (200 and 400 MPa) at 30 and 60 degrees C, the amount of SDF went up by more than eight-fold. At 200 MPa, TDF was not significantly different from control, but at 400 MPa, values varied from 38.1-64.8%. In vitro physicochemical properties of okara were also modified by HHP-treatment. Therefore, the effect of a combined treatment with hydration, temperature and HHP-technology on the improvement of the soluble fiber fraction (%) and functionality of certain vegetable by-products from the food industry could be very useful for the elaboration of food ingredients with potential health-promoting effects.