Abstract
The eighteen kinds of amino acid of the following specimen taken in the course of “Miso” processing were determined by microbiological assay technique:(1) material soybean, (2) soybean immersed in tap water, (3) steamed soybean, (4) spent liquor of steamed soybean, (5) finished “Koji”, (6) specimen obtained at the starting stage of ripening, (7) several stages of warmed ripening (a) to (f)(depends on days of ripening), and (8) several stages of natural ripening (a) to (f), numbers in blackets being in coincidence to those appearing in the Tables. Free amino acids (water-extracted fraction) were also assayed as well as the total (acid or alkali hydrolvsates). Total amino acids are shown in Tables 1 and 2, and free amino acids are in Tables 3 and 4, values being expressed as the percentage of each acid in protein (computed from the Kjeldahl nitrogen being multiplied by 5 71) through Tables 1 to 4. Tables 5 and 6 show the rate of liberation (the free amino acid per cent total). It was found that the values of total lysitie and cystine decreased by steaming (Table 1) and further decrease was seen in these amino acids at the ripening stage (Table 2). Total arginine value decreased also in the ripening stage (Table 2). No remarkable difference was observed between material soybean and “Miso” except the above mentioned acids. Proline and methionine showed the highest rate of liberation, but the former was liberated at rather ealier stage of ripening (Table 4 and 6), while cystine was, on the contrary, liberated at rather delayed stage of the ripening. No remarkable difference in total arid free amino acid patterns between warmed and natural riperiings was observed.
