Effects of thermal pre-treatment on physicochemical properties of nano-sized okara (soybean residue) insoluble dietary fiber prepared by wet media milling

Physicochemical properties and bioactive function of Japanese grape (Hovenia dulcis) pomace insoluble dietary fibre modified by ball milling and complex enzyme treatment

“…In addition, reducing the particle size results in a significant increase in electrostatic attraction and the surface activity of van der Waals forces (Kwade, ; Chen et al ., ; Liu et al ., ). Similar results have also been found in other studies (Ullah et al ., , ).…”

“…Swelling power (SP) and water soluble index (WSI) were detected according to the method of Ikram Ullah et al (2018). A 10 mL suspension of HIDF was prepared in a 15 mL centrifuge tube and centrifuged (3500 g, 15 min).…”

“…Changes in the internal and external structure of the fibres can enhance the interaction of water molecules by dipole formation and/or hydrogen bonding, which can improve the water solubility index (WSI), swelling power (WP) and water retention capacity (WRC; Chen et al, 2014). The WSI, WP and WRC of milled IDF are significantly higher than those without milling (Ullah et al, 2018). Complex enzyme modification generally leads to the fracture of milling IDF flat structures, causing fracture of the fibre matrix surface and more exposure of the inner structure.…”

“…Insoluble dietary fibre (IDF) from the secondary product is generally not included in food products due to its negative effects on food quality, such as appearance and tastes (Aravind et al, 2012). Modification of the physical and chemical properties of IDF by physical, chemical and biological methods can enhance its health benefit (Ullah et al, 2017(Ullah et al, , 2018Niu et al, 2018). The physical method has the advantages of simple technology, low cost, robust sustainability and so on.…”

“…Micro-fluidisation, wet media milling and highpressure homogenisation can effectively improve the physical, chemical and functional properties of IDF such as peach, okala and rice starch by increasing particle specific surface area reducing particle size Liu et al, 2016;Ullah et al, 2018). Wet media milling is an efficient tool for reducing the particle size of okala IDF to the submicron level and increasing its surface area and modifying its functional properties (Ullah et al, 2018). Biological methods can effectively improve the structure and nutritional value of IDF, and the technological characteristics of high dietary food.…”