Comparation of nutritional composition of Pyropia haitanensis from different sea areas of China

We compared the nutritional composition of Pyropia haitanensis from six breeding sea areas in China. The results show that the moisture content of P. haitanensis was 9.68%−12.31%, and the moisture contents of sun-dried samples in Guangdong were significantly higher than those of the machine-dried samples in the other areas (P<0.05). The contents of crude fat were all lower than 0.5% (dry mass, same as below). The ash contents ranged from 7.85% to 9.55% (Xiapu highest, Dongshan lowest). The contents of protein were 33.40%‒36.38% (Xiapu highest, Laiwu lowest). The contents of total amino acids and essential amino acids were 30.15%‒32.41% and 11.52%‒12.27%, respectively, both relatively high. However, the nutritional value score, chemical score and essential amino acid index of P. haitanensis from all the areas were all low. The essential amino acid index of Dongshan samples was the highest. Methionine+cysteine was the first limiting amino acid of P. haitanensis. The mineral elements contents were rich in P. haitanensis and varied greatly from area to area. The contents of K, Ca, Fe, Zn, Cu, Co and V in Xiapu samples, the contents of Na and Se in Nan'ao samples, the Mg content in Dongshan and Mn content in Wenzhou were the highest.