Abstract:The primary nutrients in kelp (Saccharina japonica) products cultivated under standardized and traditional long-line modes in the waters of Sanggou Bay, Shandong Province, were analyzed and compared. The results showed there was no significant difference in the moisture content of the kelp produced by the two methods, and in both cases, the moisture content was higher than 88%. The cultivation method did not significantly affect the total protein content of the kelp, but the soluble protein level was significantly different between the two methods. The fat content was low in all the kelp samples, and the difference between the products of the two cultivation methods was not significant. The essential amino acid content (except lysine) of kelp from the standardized cultivation method was higher than that from the traditional method. The amino acids responsible for flavor were higher in kelp produced by the standardized method than in kelp produced by traditional cultivation. Glutamic acid content in kelp from standardized production was high (1.75%) in comparison to other amino acids (1.27%). The fatty acid content of kelp from both cultivation modes was lower than 1%. The average levels of zinc, magnesium, sodium, and potassium in kelp from standardized cultivation were higher than traditionally produced kelp. Additionally, the soluble sugar content of kelp from standardized cultivation was significantly higher than that from traditional cultivation. The alginate content was 22.66% and 21.27% in the standardized cultivation and traditional cultivation modes, respectively. The results showed that the protein, amino acid, fatty acid, mineral elements, soluble sugar, and alginate contents in kelp produced by standardized cultivation were all higher than in kelp grown the traditional way. Therefore, the nutrient value and quality of kelp products were significantly better, when produced by standardized cultivation. The value of kelp products for food and industrial raw materials was also higher. Therefore, the standardized kelp cultivation method in Sanggou Bay has significant advantages.
