Emulsifying and physicochemical properties of soy hull hemicelluloses-soy protein isolate conjugates

Fabricating a Pickering Stabilizer from Okara Dietary Fibre Particulates by Conjugating with Soy Protein Isolate via Maillard Reaction

“…Furthermore, the irregularity in the order of increase or decrease of amino acid contents with reaction time might be due to instability or switching of the reacting ε-amino groups of the amino acids with the carbonyl groups during the dry heating process. Other reports have also asserted that conjugation occurred at the tryptophan indole group, arginine guanidine group and all the proteins N-terminus in the conjugates [18,28]. Li et al [26] who used soy proteins and dextran for conjugate formation found lower and varying contents of amino acids as compared to this present study.…”

“…The homogenized mixture was stored at 4 • C overnight, freeze-dried, and powdered. The ODF-SPI particles were allowed to form conjugates via a Maillard reaction by dry heating at 60 • C. According to the method of [18], a desiccator containing saturated sodium chloride (NaCl) was placed in the oven at 60 • C for 30 min prior to the Maillard reaction, in order to attain an equilibrium temperature and relative humidity. The water activity (a w ) of the desiccator was determined to be 0.78.…”

“…Thermograms obtained in Figure 2 showed that the thermal decomposition of conjugates begun from 83.54 • C until the maximum of 319.57 • C. Onset weight losses as shown by the endothermic peaks, are due to bound water removal from the conjugates. Emergence of the second peaks showed that the conjugates contained some matter that were being oxidized [18], or further decomposition of sugars and amino acids into flammable gases such as carbon monoxide, carbon dioxide and ammonia. The highest weight losses around 300 • C and above suggest that both intra-and inter-molecular hydrogen and electrostatic bonds became broken, leading to the loss of hydrophobic interaction, and followed by the bond breaking of C-N, C(O)-NH, and C(O)-NH 2 of amino acids with the increase in temperature [29].…”

“…This is due to water losses among ODF-SPI conjugates, which indicated varying degrees of hydrogen bonding at higher temperatures. Moreover, based on the conjugates' residual contents, increase in their percentage weight losses could be associated with increased protein-protein cross-linking interactions during Maillard reaction, thereby leading to higher thermal stability [18].…”

“…The adsorbed spectra bands are matched with amide A and amide B, to understand hydrogen bond formation and peptide chains during N-H and O-H, and amino groups interactions, respectively [20]. Amide I, II, and III are employed to study the Maillard reaction (C=O stretching, N-H bending, C-N and N-H bending vibrations, respectively) between polysaccharides and proteins [18]. The spectra of ODF-SPI mixture and conjugates as shown in Figure 3 depict the infrared bands to have been absorbed at 1015 cm −1 , 1650 cm −1 , 2925 cm −1 , and 3424 cm −1 regions.…”