Effectiveness of Microencapsulation and the Additional Supplementation of a Coating Material to Preserve the Viability of Lactobacillus Casei Cells in Apple Juice

Cheow, Derrick Hee Yang (2021) Effectiveness of Microencapsulation and the Additional Supplementation of a Coating Material to Preserve the Viability of Lactobacillus Casei Cells in Apple Juice. Final Year Project (Bachelor), Tunku Abdul Rahman University College.

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Abstract

Lactobacillus casei are probiotic cells incorporated in functional foods, designed to exert various functional health benefits when consumed and delivered to the human gut in sufficient concentrations. Nevertheless, the viability and functionality of probiotics would be suppressed via exposure to adverse conditions of the human gastrointestinal tract and food environment. This necessitates usage of microencapsulation to immobilize probiotic cells into beads to preserve their viability against adverse environmental conditions. As such, the viability of microencapsulated and free non-encapsulated Lactobacillus casei in acidic apple juice are tested, compared and investigated. Lactobacillus casei cells were first extruded into sodium alginate beads with additional coating of chitosan and guar gum, then both free and encapsulated cells were immersed into commercialized fruit juice environment and stored at 4℃ storage. The following responses of encapsulation efficiency, viability at 4℃ storage, pH measurement and total soluble solid content were initially measured and examined, then repeated every 2 weeks for a total of 4 weeks of storage. Based on the results, the encapsulation efficiency of the microcapsules has proven to be effective, reaching approximately 99% efficacy with little losses. However, the viability of free Lactobacillus casei cells have unexpectedly illustrated a lesser degree of logarithmic reduction (approximately log 8) compared to the microencapsulated cells (from log 8 to log 6) over the course of 4 weeks, which is significantly different from literature studies and expected results. Meanwhile, the pH and Brix measurements have shown slight changes for both treatments, decreasing and increasing respectively. This conclusively leads to the notion that microencapsulation has insignificant influence on Lactobacillus casei viability in fruit juice. There are several limitations to this study which may have influenced the results.