Optimization of phycobiliprotein pigments extraction from red algae Gracilaria gracilis for substitution of synthetic food colorants

• Published in: Food chemistry 2020-08, Vol.321, p.126688-126688, Article 126688
• Main Authors: Pereira, Tatiana, Barroso, Sónia, Mendes, Susana, Amaral, Renata A., Dias, Juliana R., Baptista, Teresa, Saraiva, Jorge A., Alves, Nuno M., Gil, Maria M.
• Format: Article
• Language: English
• Subjects: Extraction optimization; Gracilaria gracilis; Natural pigments; Phycobiliproteins; Response surface methodology
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2020.126688

•The extraction of PBP pigments from red algae G. gracilis was optimized using RSM.•Maceration proved to be a suitable process for PE extraction from G. gracilis.•The most impactful variable in the extraction process was extraction time.•SEM analysis revealed a more efficient cell wall rupture using maceration. The extraction of phycobiliprotein (PBP) pigments from red algae Gracilaria gracilis was optimized using maceration, ultrasound-assisted extraction (ultrasonic water bath and ultrasonic probe), high pressure-assisted extraction, and freeze-thaw. The experimental conditions, namely homogenization time (t1), buffer concentration (C), treatment time (t2), biomass: buffer ratio (R), and pressure (P), were optimized using Response Surface Methodology (RSM). The yield of phycoerythrin (PE) extracted, determined spectroscopically, was used as the response variable. Maceration was the most efficient extraction method yielding 3.6 mg PE/g biomass under the optimal conditions (t1 = t2 = 10 min; C = 0.1 M; R = 1:50). Scanning Electron Microscopy (SEM) analysis of the biomass before and after the cell disruption treatments revealed a more efficient cell wall rupture with maceration.