Production of Hypoallergenic Antibacterial Peptides from Defatted Soybean Meal in Membrane Bioreactor: A Bioprocess Engineering Study with Comprehensive Product Characterization

• Main Authors: Arij it Nath, Gábor Szécsi, Barbara Csehi, Zsuzsa Mednyánszky, Gabriella Kiskó, Éva Bányai, Mihály Dernovics, András Koris
• Format: Article
• Language: English
• Published: University of Zagreb 2017-01-01
• Series: Food Technology and Biotechnology
• Subjects: soybean meal; enzymatic hydrolysis; peptide separation; low-molecular-mass antibacterial peptides
• Online Access: http://hrcak.srce.hr/file/275135
• ISSN: 1330-9862; 1334-2606

Hypoallergenic antibacterial low-molecular-mass peptides were produced from defatted soybean meal in a membrane bioreactor. In the fi rst step, soybean meal proteins were digested with trypsin in the bioreactor, operated in batch mode. For the tryptic digestion of soybean meal protein, optimum initial soybean meal concentration of 75 g/L, temperature of 40 °C and pH=9.0 were determined. Aft er enzymatic digestion, low-molecular-mass peptides were purifi ed with cross-fl ow fl at sheet membrane (pore size 100 μm) and then with tubular ceramic ultrafi ltration membrane (molecular mass cut-off 5 kDa). Eff ects of transmembrane pressure and the use of a static turbulence promoter to reduce the concentration polarization near the ultrafi ltration membrane surface were examined and their positive eff ects were proven. For the fi ltration with ultrafi ltration membrane, transmembrane pressure of 3•105 Pa with 3-stage discontinuous diafi ltration was found optimal. The molecular mass distribution of purifi ed peptides using ultrafi ltration membrane was determined by a liquid chromatography–electrospray ionization quadrupole time-of-fl ight mass spectrometry setup. More than 96 % of the peptides (calculated as relative frequency) from the ultrafi ltration membrane permeate had the molecular mass M≤1.7 kDa and the highest molecular mass was found to be 3.1 kDa. The decrease of allergenic property due to the tryptic digestion and membrane fi ltration was determined by an enzyme-linked immunosorbent assay and it was found to exceed 99.9 %. It was also found that the peptides purifi ed in the ultrafi ltration membrane promoted the growth of Pediococcus acidilactici HA6111-2 and they possessed antibacterial activity against Bacillus cereus.