Doctor of Philosophy (PhD)


School of Nutrition and Food Sciences

Document Type



Probiotics may improve gut microbial composition and immune function. Introduction of probiotics via foods or supplements may result in the probiotics not surviving during processing and passage through the stomach to the large intestine. The overall objective of this study was to develop and investigate three delivery systems for delivering live probiotic cells (Lactobacillus plantarum NRRL B-4496) (LP). The three delivery systems were: (1) immobilized LP (~108-109 CFU/mL LP Free Cells) on purple rice bran fiber (PRF) (Delivery system 1), (2) encapsulated LP with combined pectin-rice bran extract (Delivery system 2), and (3) double encapsulated LP with protective agents (Delivery system 3). All three delivery systems were frozen prior to freeze drying and they were tested for viability of LP during processing and under gastrointestinal fluid conditions and compared with free LP cells. PRF protected cells in Delivery system 1 had less than 1 log reduction of viable cells, while the control (free LP cells) had reductions greater than 6 logs after freeze drying. The log reductions of viable LP cells protected with PRF after freeze drying and 12 weeks storage at 4 °C were between 0.7 and 1.3 log cycles. Delivery system 2 had significantly higher viability under gut conditions than free LP cells prior to freeze drying. However, the encapsulated LP did not survive during freeze drying. The third delivery system was developed by mixing LP cells with a protective agent including maltodextrin, wheat dextrin soluble fiber, or hi-maize starch. They were double encapsulated, first with pectin-rice bran extract then with whey protein isolate. Delivery system 3 had greater numbers of viable cells than Delivery system 2 after freeze drying. The whey protein isolate coating significantly improved cell viability of the encapsulated cells during freeze drying. Hi-maize starch provided better protection to the encapsulated cells during freeze drying and in simulated gastrointestinal conditions than maltrodextrin and wheat dextrin soluble fiber. Encapsulation of L. plantarum with hi-maize starch in freeze dried pectin-rice bran capsules would be a novel synbiotic supplement that may potentially be incorporated into food products such as nutrition bars, cereal products or dairy products.



Document Availability at the Time of Submission

Secure the entire work for patent and/or proprietary purposes for a period of one year. Student has submitted appropriate documentation which states: During this period the copyright owner also agrees not to exercise her/his ownership rights, including public use in works, without prior authorization from LSU. At the end of the one year period, either we or LSU may request an automatic extension for one additional year. At the end of the one year secure period (or its extension, if such is requested), the work will be released for access worldwide.

Committee Chair

Sathivel, Subramaniam



Included in

Life Sciences Commons