昆布の品質-IX

Abstract

Amino acid composition of Makombu extractives was quantitatively determined by using amino acid analyzer. The samples were as follows: raw (I), sun-dried (II-IV), left at room temperature (20°) (VII, VIII), dried at 40° (V), and 80° (VI) of the central part (including the base) of the blade, and raw (IX), and sun-dried (X) of the marginal part (including the apex). No marked differences among the amino acid pools of the extractives from the central part were found, however, a remarkable difference was recognized between the central part and the marginal part. The ratios of ninhydrin reactive nitrogen to total nitrogen of extractives from the central part were approximately 90%, but the values of the latter part were 70%. The recovered amino acid nitrogens were calculated to be as much as 83 to 97% compared to the total extractive nitrogen in the central part. The values of the latter were 57-61%. The main components of the central part were glutamic acid and aspartic acid which occupy about 60 and 30% of the total amino acids, respectively. The contents of proline and alanine followed in lesser amounts. The contents of cysteic acid, D-cystenolic acid, taurine, chondrine, and arginine were very small. Though the content of tryptophan was very small, the presence was recognized in the concentrated extractive. D-cystenolic acid was determined only in the latter part, while an unknown ninhydrin reactive substance which behaves chromatographically like urea, was found only in the central part. The compound proved not to be urea by qualitative tests. Laminin, detected by TAKEMOTO et al.5) in some species of Kombu, was not separately determined from lysine in the present analvses. Four small unknown peaks were present in the neutral and acidic fractions of the extractives of the central part, and two small unknown peaks were found in the same fractions of the latter part.