In recent years the cultivation and exploitation of Microalgae biomass has stimulated intensive research due both to its high productivity, when compared to agriculturally grown biomass, and the large relative content of more than 50% of valuable cell components, like lipids, proteins, polysaccharides, antioxidants, vitamins and pigments (Goettel et al., 2013; Luengo et al., 2014). However, the extraction of these compounds is limited by the mass transfer of these compounds through cell membranes. In this frame, thanks to the reduction of the resistances to mass transfer due to the induced permeabilization of plant cells, Pulsed Electric Field (PEF) technology can be used as a pre-treatment of concentrated microalgae suspension in order to enhance the extraction yield of valuable compounds (such as antioxidants and colorants) from the inner parts of the cells(Mahnič-Kalamiza et al., 2014). In this work the effect of different PEF treatment intensity on the extraction of valuable compound from microalgae Chlorella Vulgaris was investigated. Culture of C. vulgaris strain inoculated in TAP-medium, were cultivated in batch 26 L photo-bioreactor. Growth conditions were monitored by OD measurements at 750 nm. The algae were harvested after 18-24 days and concentrated up to a final biomass concentration of about 40-50 gdw/kgsus. PEF experiments of different intensities (E=27-35 kV/cm, and WT=50-100- 150 kJ/kg) were carried out in a laboratory scale continuous flow unit. Determinations of time-conductivity profile as well as quantification of dry matter, protein content, total polyphenolics (TP), and antioxidant activity (AA) of the supernatant were performed. Results showed a higher increase of the electrical conductivity of PEF treated suspension, when compared to the untreated sample. Moreover, the PEF treatment increased the dry matter content as well as the amount of proteins released into the supernatant from inside the algae cells. Additionally, increments of total phenolics and antioxidant activity were also detected. The results obtained from this study demonstrate the potential of PEF for improving extraction of compounds of interest from the microalgae C. vulgaris.
|Titolo:||PEF assisted extraction of valuable compounds from microalgae C. vulgaris|
|Data di pubblicazione:||2015|
|Appare nelle tipologie:||4.3 Poster|