Enriched biomass production and encapsulation of microalgae for novel food production | |
| Author | Su Aye Aye Hlaing |
| Call Number | AIT Diss no.FB-20-01 |
| Subject(s) | Microalgae--Biotechnology Functional foods--Biotechnology Encapsulation |
| Note | A Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of Doctor of Engineering in Food Engineering and Bioprocess Technology |
| Publisher | Asian Institute of Technology |
| Abstract | The cultivation of freshwater green microalga Scenedesmus obliquus and Chlorella vulgaris was investigated to enhance the biomass production with its higher contents of proteins, carbohydrates, lipids, chlorophyll, carotenoids and phenolic compounds using the Box-Behnken experimental design. Both species were cultured under phototrophic conditions using Bold’s Basal Medium (BBM) with different cultivation parameters including pH (7, 8 and 9) and salinity (10, 30 and 50 mM), and nitrogen sources (0.125, 0.5 and 1 g/L). After 18 days of cultivation, the highest biomass yield at pH 7 was 64.9 ± 0.94 mg/L/day for S.obliquus and C.vulgaris was 51.25 ± 0.79 mg/L/day using the optimized medium at a salinity concentration of 30 mM and 50 mM (w/v) and nitrogen sources of 0.125 g/L and 1 g/L, respectively. The maximum amount of biomass productivity was chosen, thereafter, to scale up the volume by using tap water. The selection and cultivation of a two-stage strategy for C.vulgaris consisting of rapid cell growth in Stage I followed by biomass production in Stage II in the 10 L flask both indoors and outdoors, which had affected the irradiance. The two-stage photoautotrophic system was set and studied to evaluate the influence of light intensity and nutrients on the growth and composition of C.vulgaris. It was observed that biomass productivity for indoor condition had a higher specific growth rate in biomass productivity and nutritional value than the outside environment for both species. The results also showed that the two-stage photoautotrophic system is not only viable but also effective. C.vulgaris biomass was encapsulated with alginate and soy protein isolate/ resistant starch by using the ionotropic gelation technique. The SEM results revealed that the surface of the beads with alginate-soy protein isolate-coated and alginateresistant starch were irregular, rough and had a dent structure. In general, all kinds of microalgae beads can stand for long periods of time in pH 1.2 and disintegrate only in intestinal condition. The muffin cake with alginate-SPI beads and alginate-resistant starch capsules was found to have similar scores with those of the control muffin cake by Hedonic analysis. However, the microalgae-loaded muffin cake was generally disliked by the panelists particularly due to its odor, texture and appearance. |
| Year | 2020 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development (SERD) |
| 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) | Anal. Anil Kumar; |
| Examination Committee(s) | Loc Thai Nguyen;Soni, Peeyush; |
| Scholarship Donor(s) | Norwegian Ministry of Foreign Affairs (NMFA),; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2020 |