Soy flour was inoculated with Lactobacillus delbrueckii ssp. lattis R0187, and incubated for 8 h, to evaluate the protein hydrolysis and identify peptides generated by this fermentation, and the impact on ACE and trypsin inhibitory activities. Aqueous protein extracts prepared from different fermentation time periods showed a decrease in soluble protein content (from 2.83 to 0.02 mg/mL), while soluble inorganic nitrogen and free amino acid contents increased (from 0.029 to 0.062% w/w, and from 0.75 to 0.90% w/w, respectively). The protein extracts were analyzed by SDS-PAGE; proteolysis was observed after 5 h incubation of inoculated soy flour, suggesting that glycinin, beta-conglycinin, and trypsin inhibitors, were hydrolyzed. Peptides were isolated by tricine-SDS-PAGE, and analyzed by MS/MS; fragments of soy anti-nutritional factors (Kunitz and Bowman-Birk trypsir, inhibitors), as well as of other soybean proteins, were identified, confirming that these proteins were hydrolyzed. The protein extracts at time 0 h and 8 h were analyzed by RP-HPLC; one fraction was analyzed by MS/MS, which identified peptides from Lactobacillus species. Determination of trypsin inhibitory activity showed less inhibition of the enzyme with inoculated soy flour compared to the control (un-inoculated soy flour), confirming the deactivation of trypsin inhibitors by fermentation. Determination of ACE inhibitory activity showed a higher inhibition with the control (86% +/- 3.0) compared to inoculated soy flour (66% +/- 7.6).
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.100754 |
| Date | January 2006 |
| Creators | Ahmarani, Jamile. |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Food Science and Agricultural Chemistry.) |
| Rights | © Jamile Ahmarani, 2006 |
| Relation | alephsysno: 002599125, proquestno: AAIMR32650, Theses scanned by UMI/ProQuest. |
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