Sub-critical water technology for enhanced extraction of carbohydrates and protein from chlorella vulgaris microalgae
Algae have many advantages such as fast growth rate, non-arable land requirement for grow and contain substantial amount of biochemical compounds such as lipid, carbohydrate and protein for value added products production. One of the new key alternatives is to extract microalgal biochemical by ut...
Saved in:
| Main Author: | |
|---|---|
| Format: | Thesis |
| Language: | English |
| Published: |
2017
|
| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/71172/1/FK%202017%2049%20-%20IR.pdf |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Algae have many advantages such as fast growth rate, non-arable land requirement for
grow and contain substantial amount of biochemical compounds such as lipid,
carbohydrate and protein for value added products production. One of the new key
alternatives is to extract microalgal biochemical by utilizing subcritical water extraction
(SWE). This technique applies hot water under pressure sufficiently retains water in
liquid state at temperature below the supercritical values. This study investigates the
effectiveness of SWE to extract protein and carbohydrate from microalgae, Chlorella
Vulgaris. The study was divided into three parts; (i) investigation of various parameters
that affect the biochemical production (protein and carbohydrates), (ii) optimization of
SWE and (iii) pre-treatment validation. Four different parameters include temperature
(180-374 ˚C), time (1-20min), biomass loading (5-40 wt%) and particle size of biomass
(38-250μm) were used to investigate on microalgal SWE. The SWE process was further
optimized using central composite design (CCD). It was found that the highest protein
and carbohydrate concentration of 31.16 g/100 g and 14.2 g/100gwere obtained at
5 wt.%microalgal biomass with 90 μm particulate size treated at 277°C for 5 min. The
TOC yield of 8.01g/100g was obtained at 229ºC for 3min with 10wt.%microalgal
biomass at 75μm particle size. Based on the statistical analysis, microalgae loading and
extraction temperature have shown the most significant factors that affect the overall
extraction of protein whereas extraction temperature were the significant factors for
carbohydrate production. TOC yields were only affected by the microalgal loading of the
microalgal biomass. This study was further investigated the effect of pre-treatment prior
to microalgal SWE. The biomass was irradiated under sonication as the pre-treatment
technique with different process parameters. The results concluded that the pre-treatment
was not required as the results were comparable with SWE without pre-treatment hence it
gives advantages in reducing the extraction costs and avoiding environmental problems
(e.g. usage of solvents). |
|---|