Suvit Tia

Separation and purification of phycocyanin from Spirulina sp. using a membrane process

The highest purity ratio of phycocyanin extract was obtained when fresh biomass was used as raw material. The crude extract was purified by membrane process using microfiltration and ultrafiltration. Membrane of pore sizes 5 μm, at feed flow rate of 150 mL min(-1), permeate flux of 58.5 L h(-1)m(-2) was selected for coarse filtration and membrane with pore size 0.8/0.2 μm at the flow rate of 100 mL min(-1), permeate flux of 336 L h(-1)m(-2) was selected for fine filtration, giving phycocyanin recovery of 88.6% and 82.9%, respectively. For ultrafiltration, membrane with MWCO at 50 kDa, 69 kPa and 75 mL min(-1) of flow rate with a mean permeate flux 26.8 L h(-1)m(-2) and a retention rate of 99% was found to be optimal. Under these filtration conditions, food grade phycocyanin with the purity around 1.0 containing c-phycocyanin as the major component was obtained.

Polysaccharide extraction from Spirulina sp. and its antioxidant capacity

To optimize polysaccharide extraction from Spirulina sp., the effect of solid-to-liquid ratio, extraction temperature and time were investigated using Box-Behnken experimental design and response surface methodology. The results showed that extraction temperature and solid-to-liquid ratio had a significant impact on the yield of polysaccharides. A polysaccharides yield of around 8.3% dry weight was obtained under the following optimized conditions: solid-to-liquid ratio of 1:45, temperature of 90°C, and time of 120 min. The polysaccharide extracts contained rhamnose, which accounted for 53% of the total sugars, with a phenolic content of 45 mg GAE/g sample.

The role of moisture movement and crust thermal property on heat and mass process during deep-fat frying

The role of moisture movement and crust thermal property on heat and mass (moisture) transfer during deep-fat frying was studied. Direct effect (as convection heat transfer) and indirect effect (as contribution to food property changes) were examined. The heat transfer model was formulated using the enthalpy approach and moving boundary concept, while the moisture transfer was expressed by Ficks law of diffusion assuming a constant diffusivity. The calculation procedure, which was controlled by the surface temperature of the sample being fried, was divided into two steps namely the initial heating period and the surface boiling period

Effect of extraction temperature on the diffusion coefficient of polysaccharides from Spirulina and the optimal separation method

The extraction temperature had a significant impact on the concentration of polysaccharides derived from solid-liquid extraction of Spirulina. The polysaccharide concentration was significantly higher when the extraction was performed at 90°C than when it was performed at 80, 70, and 50°C. This result is related to the diffusion coefficients of the polysaccharides, which increased from 1.07 × 10−12 at 50°C to 3.02 × 10−12 m2/sec at 90°C. Using the Arrhenius equation, the pre-exponential factor (D0) and the activation energy (Ea) for Spirulina polysaccharide extraction were calculated as 7.958 × 10−9 m2/sec and 24.0 kJ/mol, respectively. Among the methods used for the separation of Spirulina polysaccharides, cetyltrimethylammonium bromide (CTAB, method I) and organic solvent (ethanol, in methods II and III) provided similar yields of polysaccharides. However, the separation of polysaccharides using an ultrafiltration (UF) process (method III) and ethanol precipitation was superior to separation via CTAB or vacuum rotary evaporation (method II). The use of a membrane with a molecular weight cut-off (MWCO) of 30 kDa and an area of 0.01 m2 at a feed pressure of 103 kPa with a mean permeate flux of 39.3 L/m2/h and a retention rate of 95% was optimal for the UF process. The addition of two volumes (v/v) of ethanol, which gave a total polysaccharide content of approximately 4% dry weight, was found to be most suitable for polysaccharide precipitation. The results of a Sepharose 6B column separation showed that the molecular weights of the polysaccharides in fractions I and II were 212 and 12.6 kDa, respectively.

Stepwise extraction of high-value chemicals from Arthrospira (Spirulina) and an economic feasibility study

Highlights • Phycocyanin (8.66%) was the main product from the process of the stepwise extraction.• In addition, 3.55% TFA and 0.72% polysaccharide were coproducts from the Arthrospira residue.• Arthrospira should contain 15% phycocyanin to ensure a positive NPV of investment.