Survival and recul turability of probiotic cells during freeze drying

Neo, Pei Yin (2006) Survival and recul turability of probiotic cells during freeze drying. Universiti Malaysia Sabah. (Unpublished)


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Freeze-drying of microorganisms has been practiced commercially since a few decades ago. Although there have been many studies on the freeze dried microorganisms, there are only limited works to understand the relationship between cell survival and reculturability during freezedrying. This research was aimed to find out the survival and reculturability of probiotic cells during freeze-drying. The most crucial stage causes the greatest death of probiotic cells was in the first 6 hours of freeze-drying process which is the primary drying. However, there was not much significant effect to the cell survival in the secondary drying stage. In contrast, the reculturability of cells need longer time during the secondary drying compared to primary drying. This was due to the higher population of nonlethally injured cells in the secondary drying stage compared to primary drying stage of freeze-drying. A method was developed in determining the reculturability of freeze-drying cells. Generally the highest percentage of cell survival on the primary drying of freeze-drying were L. casei shirota 34.34%, followed by L. casei 01 28.27% and lastly 21.21% for L. acidophilus ATCC 4356. Meanwhile the highest percentage of cells survival on the secondary drying of freeze-drying were L. casei shirota 33.60%, followed by L. casei 01 20.82% and lastly 19.93% for L. acidophilus ATCC 4356. Finally, L. acidophilus A Tee 4356 has the highest specific death rate which was 0.3186 h�¹ compared to L. casei 01 at 0.2432 h�¹ and L. casei shirota at 0.2347 h�¹.

Item Type: Academic Exercise
Keyword: freeze-drying microorganism, cell survival, reculturability, L. casei shirota
Subjects: T Technology > TA Engineering (General). Civil engineering (General)
Department: SCHOOL > School of Engineering and Information Technology
Date Deposited: 01 Apr 2014 10:34
Last Modified: 12 Oct 2017 14:22

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