title: Effect of Drying Methods on Protein and DNA Conformation Changes in Lactobacillus rhamnosus GG Cells by Fourier Transform Infrared Spectroscopy.
abstract: Microencapsulation protects cells against environmental stress encountered during the production of probiotics, which are used as live microbial food ingredients. Freeze-drying and spray-drying are used in the preparation of powdered microencapsulated probiotics. This study examines the ability of Fourier transform infrared (FTIR) spectroscopy to detect differences in cells exposed to freeze-drying and spray-drying of encapsulated Lactobacillus rhamnosus GG cells. The FTIR analysis clearly demonstrated there were more significant molecular changes in lipid, fatty acid content, protein, and DNA conformation of nonencapsulated compared to encapsulated bacterial cells. The technique was also able to differentiate between spray-dried and freeze-dried cells. The results also revealed the extent of protection from a protein-carbohydrate-based encapsulant matrix on the cells depending on the type drying process. The extent of this protection to the dehydration stress was shown to be less in spray-dried cells than in freeze-dried cells. This suggests that FTIR could be used as a rapid, noninvasive, and real-time measurement technique to detect detrimental drying effects on cells.
authors.affiliation: CSIRO Agriculture and Food , 671 Sneydes Road, Werribee, Victoria 3030, Australia.
authors.forename: Mya M
authors.identifier: http://orcid.org/0000-0002-7351-864X
authors.initials: MM
authors.lastname: Hlaing
authors.affiliation: Centre for Biospectroscopy, School of Chemistry, Monash University , Clayton, Victoria 3800, Australia.
authors.forename: Bayden R
authors.initials: BR
authors.lastname: Wood
authors.affiliation: Centre for Biospectroscopy, School of Chemistry, Monash University , Clayton, Victoria 3800, Australia.
authors.forename: Don
authors.initials: D
authors.lastname: McNaughton
authors.affiliation: CSIRO Agriculture and Food , 671 Sneydes Road, Werribee, Victoria 3030, Australia.
authors.forename: DanYang
authors.initials: D
authors.lastname: Ying
authors.affiliation: CSIRO Agriculture and Food , 671 Sneydes Road, Werribee, Victoria 3030, Australia.
authors.forename: Geoff
authors.initials: G
authors.lastname: Dumsday
authors.affiliation: CSIRO Agriculture and Food , 671 Sneydes Road, Werribee, Victoria 3030, Australia.
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: Augustin
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry*; D004269:DNA, Bacterial / Q000737:chemistry*; D005612:Freeze Drying; D052201:Lacticaseibacillus rhamnosus / Q000737:chemistry* / Q000254:growth & development; D050296:Microbial Viability; D009690:Nucleic Acid Conformation; D019936:Probiotics / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial
keywords: Fourier transform infrared spectroscopy; freeze-drying; microencapsulation; probiotics; spray-drying