Exploring the Use of a Modified High-Temperature, Short-Time Continuous Heat Exchanger with Extended Holding Time (HTST-EHT) for Thermal Inactivation of Trypsin Following Selective Enzymatic Hydrolysis of the β-Lactoglobulin Fraction in Whey Protein Isolate.
dc.contributor.author | Sáez, Laura | |
dc.contributor.author | Murphy, Eoin | |
dc.contributor.author | FitzGerald, Richard J | |
dc.contributor.author | Kelly, Philip | |
dc.date.accessioned | 2020-06-16T11:47:27Z | |
dc.date.available | 2020-06-16T11:47:27Z | |
dc.date.issued | 2019-08-26 | |
dc.identifier.citation | Sáez, L.; Murphy, E.; FitzGerald, R.J.; Kelly, P. Exploring the Use of a Modified High-Temperature, Short-Time Continuous Heat Exchanger with Extended Holding Time (HTST-EHT) for Thermal Inactivation of Trypsin Following Selective Enzymatic Hydrolysis of the β-Lactoglobulin Fraction in Whey Protein Isolate. Foods 2019, 8, 367. doi:https://doi.org/10.3390/foods8090367 | en_US |
dc.identifier.issn | 2304-8158 | |
dc.identifier.uri | http://hdl.handle.net/11019/1983 | |
dc.description | peer-reviewed | en_US |
dc.description.abstract | Tryptic hydrolysis of whey protein isolate under specific incubation conditions including a relatively high enzyme:substrate (E:S) ratio of 1:10 is known to preferentially hydrolyse β-lactoglobulin (β-LG), while retaining the other major whey protein fraction, i.e., α-lactalbumin (α-LA) mainly intact. An objective of the present work was to explore the effects of reducing E:S (1:10, 1:30, 1:50, 1:100) on the selective hydrolysis of β-LG by trypsin at pH 8.5 and 25 °C in a 5% (w/v) WPI solution during incubation periods ranging from 1 to 7 h. In addition, the use of a pilot-scale continuous high-temperature, short-time (HTST) heat exchanger with an extended holding time (EHT) of 5 min as a means of inactivating trypsin to terminate hydrolysis was compared with laboratory-based acidification to <pH 3 by the addition of HCl, and batch sample heating in a water bath at 85 °C. An E:S of 1:10 resulted in 100% and 30% of β-LG and α-LA hydrolysis, respectively, after 3 h, while an E:S reduction to 1:30 and 1:50 led >90% β-LG hydrolysis after respective incubation periods of 4 and 6 h, with <5% hydrolysis of α-LA in the case of 1:50. Continuous HTST-EHT treatment was shown to be an effective inactivation process allowing for the maintenance of substrate selectivity. However, HTST-EHT heating resulted in protein aggregation, which negatively impacts the downstream recovery of intact α-LA. An optimum E:S was determined to be 1:50, with an incubation time ranging from 3 h to 7 h leading to 90% β-LG hydrolysis and minimal degradation of α-LA. Alternative batch heating by means of a water bath to inactivate trypsin caused considerable digestion of α-LA, while acidification to <pH 3.0 restricted subsequent functional applications of the protein. | en_US |
dc.language.iso | en | en_US |
dc.publisher | MDPI | en_US |
dc.relation.ispartofseries | Foods;Vol. 8 (9) | |
dc.rights | Attribution-NonCommercial-ShareAlike 3.0 United States | * |
dc.rights.uri | http://creativecommons.org/licenses/by-nc-sa/3.0/us/ | * |
dc.subject | Hydrolysis | en_US |
dc.subject | WPI | en_US |
dc.subject | thermal inactivation | en_US |
dc.subject | trypsin | en_US |
dc.subject | α-lactalbumin | en_US |
dc.subject | β-lactoglobulin | en_US |
dc.title | Exploring the Use of a Modified High-Temperature, Short-Time Continuous Heat Exchanger with Extended Holding Time (HTST-EHT) for Thermal Inactivation of Trypsin Following Selective Enzymatic Hydrolysis of the β-Lactoglobulin Fraction in Whey Protein Isolate. | en_US |
dc.type | Article | en_US |
dc.identifier.doi | https://doi.org/10.3390/foods8090367 | |
dc.contributor.sponsor | Enterprise Ireland | en_US |
dc.contributor.sponsorGrantNumber | TC20130001 | en_US |
refterms.dateFOA | 2020-06-16T11:47:27Z | |
dc.source.journaltitle | Foods (Basel, Switzerland) |