Calcium chloride cacl2

All reagents were of analytical grade, and water was obtained with a Milli-Q system from Millipore (Bedford, MA, USA). Acetonitrile (ACN) was from Scharlau (Barcelona, Spain), di-sodium tetraborate decahydrate (borate buffer) from Merck (Darmstadt, Germany), and standard amino acids (AA-18) from Fluka (Buchs, Switzerland). Glutaraldehyde, sodium borohydrate (NaHB4), sodium tetraborate, β-mercaptoethanol, o-phthaldialdehyde (OPA), L-glutathione (GSH), and bovine serum albumin (BSA) were acquired from Sigma-Aldrich (St Louis, MO, USA). Hydrochloric acid (HCl) and calcium chloride (CaCl2) were from Panreac (Darmstadt, Germany). Alcalase was kindly donated by Novozymes Spain S.A. (Madrid, Spain).

Spirulina biomass (LEB strain-18), batch 2014, was provided by the Biochemical Engineering Laboratory of the Federal University of Rio Grande, isolated from the Mangueira lagoon (33°302′133 S, 53°082′593 O), located in Santa Vitória do Palmar, RS, Brazil [32 (link)] and supplemented with 20% Zarrouk medium [33 (link)]. The dried biomass was provided in the form of pellets and subsequently ground in a ball mill (Model Q298-2) and sieved in a sieve shaker, 200 mesh, to homogenize the particle size, resulting in a particle size of 88 µm. Powdered biomass was packaged in vacuum inside high-density polyethylene containers (HDPE) with a capacity of 500 g and stored under refrigeration at a temperature of ~7 °C until further analysis. Pepsin from porcine gastric mucosa (≥2500 U·mg⁻¹), bile extract porcine, pancreatin from porcine pancreas (8× USP), Pefabloc^® SC, and the salts used for the preparation of oral, gastric, and intestinal electrolyte solutions were purchased from Sigma-Aldrich. Sodium alginate (PROTONAL CR8223, M/G ratio 65/35 and 259–340 kDa) from FMC Biopolymer was kindly supplied by Eurosalmo (Portugal). Calcium chloride (CaCl₂) was purchased from Panreac (Barcelona, Spain).