Cell pretreatment with ethylenediaminetetraacetic acid for selective extraction of C‐phycocyanin with food grade purity

Abstract

C‐phycocyanin (C‐PC) is a natural blue dye, and depending on its purity, which is measured by the ratio between the absorbance of the chromophore (A620) and the absorbance of the proteins (A280), it can be used in food (purity > 0.7), cosmetics (purity > 1.5), and therapeutic treatments (purity > 4.0). Several physical, chemical, and enzymatic methods of extraction are reported, however, few are able to extract C‐PC with purity above 0.7. An innovative method of C‐PC extraction with food grade purity from wet Spirulina platensis biomass is proposed. The cells were pretreated with ethylenediaminetetraacetic acid and subsequent C‐PC extraction was performed with tris‐(hydroxymethyl) aminomethane‐SO4 buffer. C‐PC was released after 12 h of cell pretreatment. Six variables of the extraction process were evaluated. The extraction temperature significantly influenced C‐PC extraction yield and purity. In the best condition of cell pretreatment and extraction, C‐PC with purity of 1.0 and extraction yield of 129.0 mg/g could be obtained to be used as a food dye without any purification process. Lastly, an ultrafiltration process was integrated and C‐PC was concentrated 8.8‐fold, resulting in purity of 1.6 and recovery of 93.4%.

A comprehensive dataset on the extraction of pigments from Oscillatoria spp.

“…Higher purity ratios signify a greater concentration of the desired phycobiliprotein with fewer contaminants or other proteins. Phycobiliprotein purity more than 0.7 is regarded as food grade, purity over 1.5 as cosmetic grade, more than 3.9 as reactive grade and above 4.0 as an analytical grade [10] The purification factor of phycocyanin, phycoerythrin, and allophycocyanin extract was determined spectrophotometrically by A 620/A 280, A 565/A 280 and A 650/A 280 ratio [8] .…”

Preparation of high-purity R-phycoerythrin and R-phycocyanin from Pyropia yezoensis in membrane chromatography

“…In 2020 the price of PBPs varied from 55 to 245 US$ per mg, depending on the purity of PBPs (A λmax /A 280 ). The current standards of the grade classification of PBPs are as follows: purity > 0.7 for food grade, > 1.5 for cosmetic grade and > 4.0 for analytical grade (Sala et al 2018).…”

A simple method for rapid purification of phycobiliproteins from Arthrospira platensis and Porphyridium cruentum biomass

“…The commercial value of a phycobiliprotein is strongly dependent on its purity grade, which is usually evaluated by the ratio between the value of phycobiliprotein absorbance maximum (within 540-570 nm for phycoerythrin, 615-620 nm for phycocyanin, and around 650 for allophycocyanin) and the absorbance value at 280 nm, which is related to the total amount of proteins detectable in the product. Phycobiliprotein purity greater than 0.7 is considered as food grade, greater than 1.5 as cosmetic grade, greater than 3.9 as reactive grade and greater than 4.0 as analytical grade [11,12]. Many methods have been proposed to purify phycobiliproteins and particularly phycocyanin from cyanobacterial or algal biomass sources [2,5,.…”

“…A few simplified chromatographic purification procedures, more suitable to be used at a large scale production, have been proposed [17,21,[23][24][25][26][27]31,34,35]. Conversely, only a few protocols completely avoiding the expensive and time consuming column chromatography purification steps have been proposed [11,12,[36][37][38][41][42][43][44][45][46][47]. Among these, only procedures applying (1) aqueous two phase extraction steps coupled to ultrafiltration (which also can be a time consuming step) [12,36,42] or (2) membrane chromatography (MC) [47,48] provide analytical grade products.…”