Characterization of bloom formation on open sun-dried squid (Illex argentinus): A chemical composition perspective

A modified intermittent sun-drying process was conducted to investigate the mechanism and chemical composition of bloom formation on dried squid (Illex argentinus). The bloom layer on the squid surface consisted of free amino acids and fat. Fat and free amino acid components were extracted and analyzed using SEM-EDX, FT-IR, GC, and HPLC. Nitrogenous and fatty acid-containing crystals in the bloom were characterized. The nitrogenous fraction primarily contained taurine (866 ± 177 mg/g dry weight), glycine (82 ± 7 mg/g DW), alanine (381 ± 56 mg/g DW), and glutamic acid (178 ± 26 mg/g DW), whereas the fat fraction was rich in palmitic acid (29 %), eicosapentaenoic acid (16 %), and docosahexaenoic acid (41 %). Tempering treatments at night facilitated water redistribution and the migration of amino acids and fat to the surface. The dried squid was stored in a desiccator at 30 ± 3 °C with a saturated NaCl solution to maintain 75 % humidity. After 10 days, surface blooming occurred, enhancing the distinctive organoleptic properties of sun-dried squid.