Valorisation écoefficiente du lactosérum doux par procédés électrodialytiques pour la production de fractions phospholipidique et peptidique potentiellement bioactives

Authors: Faucher, Mélanie
Advisor: Bazinet, LaurentGaaloul, Sami
Abstract: Sweet whey, a dairy coproduct, is mainly used in food applications, where its components' functional and nutritional properties are exploited. However, for such applications, phospholipids (PLs), residual lipids found in whey, may lead to limitations of its use. Furthermore, PLs and peptides from the hydrolysis of whey proteins demonstrate bioactivities that could make possible their use as nutraceuticals. Thereby, the objectives of this research was to ecoefficiently produce PL and peptide fractions from sweet whey using electrodialytic processes. Indeed, electrodialysis with bipolar membrane (EDBM) seems promising to defat sweet whey whereas electrodialysis with ultrafiltration membrane (EDUF) can be used to separate peptides from a hydrolysate. The first results obtained demonstrated that, unlike the dilution applied after EDBM treatment, the concentration factor of whey had a negligible impact on the defatting rates and consequently on the lipoprotein complex formation. Moreover, the results revealed a protein precipitation phenomenon, influenced by the concentration factor. Thereby, the use of a highly concentrated sweet whey was not favorable to the defatting process. There after, different dilution factors following EDBM treatment were tested. The defattingrates reached a plateau with the increase of the dilution factor and lipoprotein complex formation was favored by a decrease in ionic strength around 80 %. Moreover, it was possible to demonstrate that the process could be used to specifically recover PLs; a PL fraction containing mainly phosphatidylserine and phosphatidylethanolamine was produced. Also, to compare the different conditions tested, ecoefficiency scores were used to determine the most favorable conditions. Furthermore, the dilution applied after EDBM treatment for the defatting process led to constraints relative to the large volumes produced. Demineralization by conventional electrodialysis and diafiltration were tested to replace the dilution step. Thus, the results obtained demonstrated that the lipoprotein complex formation and consequently the PL recovery was, not only due to the decrease in ionic strength, but also to the greater removal of divalent cations (calcium and magnesium, ionic species for which PLs have affinity). There by, a defatting process combining EDBM and conventional electrodialysis appeared to be the best option to produce a PL fraction. Finally, to produce a peptide fraction enriched with bioactive peptide, a complex whey protein hydrolysate was separated by EDUF at a semi-industrial scale. The separation was characterized by high peptide migration parameters and allowed to generate a peptide fraction containing 18 main components (peptides). Along with these components, lactose was also recovered in the peptide fraction due to a lactose transfer phenomenon during process. Nevertheless, the peptide fraction produced exhibited in vitro inhibiting activities against dipeptidyl peptidase-IV and angiotensin converting enzyme higher that the ones reported for the initial hydrolysate. Thus, this project allowed to valorize sweet whey by the production of potential bioactive fractions using electrodialytic processes. Moreover, these two processes could be combined. In a first phase, sweet whey would be defatted, then after a concentration by ultrafiltration, the retentate would be hydrolyzed and separated by EDUF to produce a peptide fraction with improved bioactivities. Furthermore, new knowledge was acquired regarding the mechanisms involved inlipoprotein complex formation and the migration and fouling phenomena that could occur during EDBM and EDUF treatments.
Document Type: Thèse de doctorat
Issue Date: 2022
Open Access Date: 27 June 2022
Grantor: Université Laval
Collection:Thèses et mémoires

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