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Conference Paper: Effect of drying methods on microencapsulated bacteria on secondary protein structure and glass transition temperature as studied by FTIR and DSC

TitleEffect of drying methods on microencapsulated bacteria on secondary protein structure and glass transition temperature as studied by FTIR and DSC
Authors
KeywordsMicroencapsulation
FTIR
DSC
Issue Date2013
PublisherElsevier Inc. The Journal's web site is located at http://www.journalofdairyscience.org/
Citation
The 2013 Joint Annual Meeting of the American Dairy Science Association (ADSA) and American Society of Animal Science (ASAS), Indianapolis, IN., 8-12 July 2013. In Journal of Dairy Science, 2013, v. 96 e-suppl. 1, p. 461-462, abstract no. 498 How to Cite?
AbstractThe objective of this study was to examine the effect of drying methods on microencapsulated L. acidophilus and L. cremoris on secondary protein structure and glass transition temperature. Protective mechanism of casein-based microcapsule containing mannitol on L. acidophilus and L. lactis ssp. cremoris and glass transition of the microcapsules were studied after spray- or freeze-drying and after 10 week of storage in aluminum foil pouch containing different desiccants (NaOH, LiCl or silica gel) at 25°C. An in situ FTIR analysis was carried out to recognize any changes in fatty acids of bacterial cell envelopes; interaction between polar site of cell envelopes and microcapsules, as well as alteration of their secondary protein structures, whereas DSC was used to determine glass transition (Tg) of microcapsules. Hierarchical cluster analysis based on functional groups of phospholipid bilayers of cell envelopes and secondary protein structures was also carried out to classify the microencapsulated bacteria. The results showed that drying process did not affect fatty acids and secondary protein structures of bacteria, however, those structures were affected during storage depending upon the type of desiccant. Interaction between bacterial cell envelopes and microencapsulant occurred after drying as shown by alteration of wavelength of P = O symmetric of cell envelopes from 1075 cm−1 to 1047 and 1048 cm−1 (fresh L. acidophilus, freeze-dried and spray dried cells, respectively). Similar phenomenon was demonstrated by L. cremoris. However, these structures were maintained after storage in foil pouch containing NaOH. Method of drying and type of desiccants influenced the level of similarities of microencapsulated bacteria. Desiccants and method of drying affected glass transition; yet no Tg ≤ 25°C was detected. This study demonstrated that the changes in fatty acids and secondary structures of the microencapsulated bacteria still occurred during storage at Tg above the room temperature indicating that glass state did not completely prevent chemical activities.
DescriptionSection: Microbiology
Oral Session: Dairy Foods: Microbiology
This journal suppl. entitled: Abstracts: American Dairy Science Association®, American Society of Animal Science ... 2013
The Conference program's website is located at http://www.jtmtg.org/JAM/2013/program.asp
Persistent Identifierhttp://hdl.handle.net/10722/205079
ISSN
2015 Impact Factor: 2.408
2015 SCImago Journal Rankings: 1.401

 

DC FieldValueLanguage
dc.contributor.authorDianawati, Den_US
dc.contributor.authorShah, Nen_US
dc.date.accessioned2014-09-20T01:20:00Z-
dc.date.available2014-09-20T01:20:00Z-
dc.date.issued2013en_US
dc.identifier.citationThe 2013 Joint Annual Meeting of the American Dairy Science Association (ADSA) and American Society of Animal Science (ASAS), Indianapolis, IN., 8-12 July 2013. In Journal of Dairy Science, 2013, v. 96 e-suppl. 1, p. 461-462, abstract no. 498en_US
dc.identifier.issn0022-0302-
dc.identifier.urihttp://hdl.handle.net/10722/205079-
dc.descriptionSection: Microbiology-
dc.descriptionOral Session: Dairy Foods: Microbiology-
dc.descriptionThis journal suppl. entitled: Abstracts: American Dairy Science Association®, American Society of Animal Science ... 2013-
dc.descriptionThe Conference program's website is located at http://www.jtmtg.org/JAM/2013/program.asp-
dc.description.abstractThe objective of this study was to examine the effect of drying methods on microencapsulated L. acidophilus and L. cremoris on secondary protein structure and glass transition temperature. Protective mechanism of casein-based microcapsule containing mannitol on L. acidophilus and L. lactis ssp. cremoris and glass transition of the microcapsules were studied after spray- or freeze-drying and after 10 week of storage in aluminum foil pouch containing different desiccants (NaOH, LiCl or silica gel) at 25°C. An in situ FTIR analysis was carried out to recognize any changes in fatty acids of bacterial cell envelopes; interaction between polar site of cell envelopes and microcapsules, as well as alteration of their secondary protein structures, whereas DSC was used to determine glass transition (Tg) of microcapsules. Hierarchical cluster analysis based on functional groups of phospholipid bilayers of cell envelopes and secondary protein structures was also carried out to classify the microencapsulated bacteria. The results showed that drying process did not affect fatty acids and secondary protein structures of bacteria, however, those structures were affected during storage depending upon the type of desiccant. Interaction between bacterial cell envelopes and microencapsulant occurred after drying as shown by alteration of wavelength of P = O symmetric of cell envelopes from 1075 cm−1 to 1047 and 1048 cm−1 (fresh L. acidophilus, freeze-dried and spray dried cells, respectively). Similar phenomenon was demonstrated by L. cremoris. However, these structures were maintained after storage in foil pouch containing NaOH. Method of drying and type of desiccants influenced the level of similarities of microencapsulated bacteria. Desiccants and method of drying affected glass transition; yet no Tg ≤ 25°C was detected. This study demonstrated that the changes in fatty acids and secondary structures of the microencapsulated bacteria still occurred during storage at Tg above the room temperature indicating that glass state did not completely prevent chemical activities.-
dc.languageengen_US
dc.publisherElsevier Inc. The Journal's web site is located at http://www.journalofdairyscience.org/-
dc.relation.ispartofJournal of Dairy Scienceen_US
dc.subjectMicroencapsulation-
dc.subjectFTIR-
dc.subjectDSC-
dc.titleEffect of drying methods on microencapsulated bacteria on secondary protein structure and glass transition temperature as studied by FTIR and DSCen_US
dc.typeConference_Paperen_US
dc.identifier.emailShah, N: npshah@hku.hken_US
dc.identifier.authorityShah, N=rp01571en_US
dc.description.naturelink_to_OA_fulltext-
dc.identifier.hkuros240726en_US
dc.identifier.volume96-
dc.identifier.issuee-suppl. 1-
dc.identifier.spage461-
dc.identifier.epage462-
dc.publisher.placeUnited States-

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