*2.2. Protein Hydrolysis*

For protein hydrolysis, lyophilized *Spirulina platensis* protein was dispersed in distilled water (DW) to achieve a protein concentration of 3% (*w*/*v*). Protein hydrolysates were produced by pepsin protease for 240 min. The hydrolysis conditions were set as follows: pH 2, temperature 37 ◦C, enzyme-to-substrate (E/S) ratio of 6% (*w/w*). The hydrolysis reaction was performed in a shaker incubator (Unimax 1010; Heidolph, Schwabach, Germany), then the enzymes were thermally inactivated (90 ◦C, 10 min), and the solution was cooled down to room temperature. The hydrolysate solution was then centrifugated at 4550× *g* for 10 min and the supernatant was collected for further analysis [4].
