Evaluation of the effects of organic loading on the bactericidal activity of ozone-nanobubbles | |
| Author | Uyen, Thanh Thao Bui |
| Call Number | AIT Thesis no.FB-23-03 |
| Subject(s) | Microbubbles Ozone |
| Note | A Thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Food Engineering and Bioprocess Technology |
| Publisher | Asian Institute of Technology |
| Abstract | Ozone-nanobubbles (O3-NBs) have an extensive range of applications in various industrial segments due to their unique characteristics and noticeable antimicrobial properties. However, there are still several considerable factors influencing their bactericidal efficacy, including the type and concentration of foreign matters. This study focusses on investigating the properties and combinational effects of O3-NBs on two typical pathogenic microorganisms (S. aureus and E. coli) in the presence of different organic matters as food components (soluble starch and egg albumin). After 15 min of generation in deionized (DI) water, a dominant concentration of obtained bubbles had an approximately average size of 164 nm, zeta potential (ZP) value of |30.8| ± 9.7 mV, and a nanobubble-fluid surface tension of 68.1 ± 0.4 mN/m. The presence of organic substances notably affected O3-NB characteristics in terms of increasing bubble size, surface tension of nanobubble-containing dispersions, lowering dissolved gas concentration and absolute ZP values of the produced bubbles. This indicated the impact of the present organic molecules on the stability of O3-NBs. Furthermore, the obtained result supported the hypothesis regarding the influence of organic loading on microbial inactivation of the combinational treatment. O3-NBs generated in DI water resulted in significant reduction of S. aureus and E. coli population in cell suspension and on surface of different fresh-cut vegetables. The addition of starch and egg albumin remarkable interfere with antimicrobial activity of the treatment, represented by the negligible reduction in bacterial concentration. The findings also revealed that compared to soluble starch, egg albumin led to more noticeable impacts on properties and bacterial reduction of O3-NBs. The outcomes provide some more details about the interaction of O3-NBs with foreign organic substance and may be useful for sterilization process in food-related sectors. |
| Year | 2023 |
| Type | Thesis |
| School | School of Environment, Resources, and Development |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Food Engineering and Bioprocess Technology (FB) |
| Chairperson(s) | Loc, Thai Nguyen; |
| Examination Committee(s) | Ha, Thanh Dong;Anal, Anil Kumar; |
| Scholarship Donor(s) | AIT Scholarships; |
| Degree | Thesis (M. Sc.) - Asian Institute of Technology, 2023 |