Influence of thermal and electrical effects of ohmic heating on C-phycocyanin properties and biocompounds recovery from Spirulina platensis

Spirulina platensis is interesting for the food industry due to its overall composition and high content in C-phycocyanin. However, the sensitivity of C-phycocyanin makes its extraction a delicate process. The present study focuses on assessing the use of ohmic heating (OH) in the recovery of C-phycocyanin and other relevant compounds as an alternative method to freeze-thawing or conventional heating. Different ohmic and conventional heating treatments were applied both to purified C-phycocyanin and Spirulina powder. Evaluation of fluorescence and circular dichroism showed that moderated electric fields increased C-phycocyanin stability. This was confirmed in the extraction trials which revealed that OH assisted extraction at higher temperatures (44 degrees C), and shorter times (30 min) allowed significant higher extraction yield of C-phycocyanin (45 mg/g(dw) Spirulina), in comparison with conventional heating and freeze-thawing. OH allowed also up to 80% higher yields in phenolic compounds and carbohydrates.