Abstract:In this study, effect of pH conditions in the extraction process on protein yield, changes of nutritional components and nutritional value of protein isolates from whole and muscle of tiger shrimp (Penaeus Monodon) using isoelectric solubilization/precipitation (ISP) was investigated. Protein isolates were obtained from tiger shrimp at a ratio of 1:9 with cold distilled water, dissolved at pH 2.0, 3.0 and pH 11.0, 12.0, subsequently precipitated at pH 5.5. Protein yields from whole and muscle of tiger shrimp were 75.67%~82.72% and 68.33%~80.5%, respectively. The highest protein extraction was observed at pH 2.0 and 12.0. Crude protein content in protein isolates extracted from both materials was more than 71% (dry weight), and the acidic treatments yielded significantly (p<0.05) higher contents of crude protein and ash in the recovered proteins than the basic treatments. The protein isolates from both pH treatments had increased contents of essential, semi essential and total amino acids as well as flavor amino acids but lowered content of shrimp-flavor amino acids than those of the starting materials. And their essential amino acids content met the FAO/WHO/UNU requirements. Both basic and acidic treatments gave rise to the removal of Cu, Mg, K, Zn and Mn, and the basic treatments yielded protein with significantly (p<0.05) higher amount of minerals than the acidic treatments. Therefore, protein isolates prepared from whole and muscle of tiger shrimp via ISP were high in protein yield and nutritional?value and may be used for the development of human food and animal feeds.
