Preparation and characterization of protein isolate from Yellowfin tuna Thunnus albacares roe by isoelectric solubilization/precipitation process

摘要: Isoelectric solubilization/precipitation (ISP) processing allows selective, pH-induced water solubility of proteins with concurrent separation lipids and removal materials not intended for human consumption such as bone, scales, skin, etc. Recovered retain functional properties nutritional value. Four roe protein isolates (RPIs) from yellowfin tuna were prepared under different solubilization precipitation condition (pH 11/4.5, pH 11/5.5, pH 12/4.5 pH 12/5.5). RPIs contained 2.3–5.0 % moisture, 79.1–87.8 % protein, 5.6–7.4 % lipid 3.0–3.8 % ash. Protein content RPI-1 RPI-2 precipitated at pH 4.5 5.5 after alkaline pH 11, was higher than those RPI-3 RPI-4 pH 12 (P < 0.05). Lipid (5.6–7.4 %) lower that freeze-dried concentrate (10.6 %). And leucine lysine the most abundant amino acids (8.8–9.4 8.5–8.9 g/100 g respectively). S, Na, P, K minerals major elements in RPIs. SDS-PAGE showed bands 100, 45, 25 15 K. Moisture contents process a 2’nd byproduct 98.9–99.0 1.3–1.8 %, respectively. Therefore, isolate could be promising source valuable nutrients food animal feeds.