• Augustin, Maryann
• Hlaing, Mya Myintzu
• Ying, Danyang
• Wood, Bayden
• Mcnaughton, Don

Abstract

Microencapsulation protects cells against environmental stress encountered during the production of probiotics, live microbial food ingredients. Freeze-drying and spray-drying are used in the preparation of powdered microencapsulated probiotics.This study reports on the application of Fourier transform infrared (FTIR) spectroscopy to study the effect of freeze-drying and spray-drying techniques used for dehydration of Lactobacillus rhamnosus GG cells encapsulated within a protein-carbohydrate matrix. The FTIR analysis was carried out to follow molecular changes in lipid, fatty acids contents, protein and DNA conformation of bacterial cells which can be interpreted as the result of detrimental drying effects on the cells. The results show changes in the spectral features associated with the protein secondary structures after drying, an effect of interaction between bacterial cell membrane and the encapsulant materials. The results also reveal the extent of protection from a protein-carbohydrate based encapsulant matrix on the cells depending on the type of different drying processes. The extent of this protection to the dehydration stress is shown to be less in spray-dried cells than in freeze-dried cells.

Topics

• impedance spectroscopy
• laser emission spectroscopy
• Fourier transform infrared spectroscopy
• drying