Components and nutritional quality of shrimp processing by-products

The components and nutritional quality of processing by-products (heads, shells and tails) of Northern pink shrimp (NPS, Pandalus borealis) and spotted shrimp (SS, Trachypena curvirostris) caught near Tongyeong, Korea, were investigated. Crude protein contents were in the range of 9.3–11.6% and total fat content was approximately 0.7%. Volatile basic nitrogen (VBN) values of the processing by products were lower than those of the edible parts. The number of viable cells (CFU/g) was 1.2–2.8×104, which is acceptable for seafood processing, and heavy metals (Hg, Pb and Cd) were present in trace amounts. Aspartic acid, glutamic acid, phenylalanine, lysine and arginine were the predominant amino acids in the protein fraction. The calcium content (3000 mg/100 g) was higher than those of phosphorus (400 mg/100 g), sodium (270 mg/100 g) and magnesium (100 mg/100 g) while manganese and iron were present in trace amounts. There was no significant difference in the non-protein nitrogen contents between the edible parts and the processing by-products of shrimp. The total content of free amino acids of the processing by-products (2000 mg/100 g) was 15% higher than that of the edible parts (1700 mg/100 g). Major free amino acids were taurine, threonine, leucine, tryrosine and phenylalanine.