The purple laver, Prophyla tenera K., is known among the Japanese as “asakusa-nori”, one of their favorite items of food. High flavour of the seaweed is much regarded of particularly when it is dried into a crispy sheet. The present study was intended to determine a factor responible for the flavour, using the materials which had been seeded and reared at different localities.
The results of distillation of volatile compuonds, determinations of nitorogen obtained by KJELDAHL's method and of phosphorus by ALLEN's indicated that the higher flavour is correlated with the amount of nitorogen as well as volatile compounds contained in the frond of the seaweed, The fact is likly dependent on the environment of rearing grounds but not on that of seeding grounds (table 1). When two samples, the one collected in the middle of January and the other a the end of March from the same rearing ground, were compared, the latter was found containg volatile compounds more than the former (table 2).
Fatty acids obtained from the volatile fraction of the seaweed are formic acid, acetic acid, Droponic acid, butyric acid, and valeric acid: palmitic acid being found present in the fraction soluble in sodium hydroxide.
Chromatostrip examination of carbonyl separated from the seaweed showed it consisting of three different compounds with Rf. 0.26, 0.33 and 0.47. The facts that the first value agree with the spot furfurol gives under chromatostorip and that the compound responded to anilin acetate just as furfurol does seem to have proved presence of this substance in the compound.
When terpene compound gained by fractional distillation was examined with help of chroma storip, there were found α-pinene, d-limonene, terpinolene, geraniol, and carvone existing in it along with a neutral oil that gives forth Rf. value 0.40 (tables 3 and 4). The gas that could not be condensed in the course of distillation did not show dimethylsulfide and smelled like a sort) of amine.