The Correlation between the affinity of mold with 9-straight chain alkylated acridine derivatives and the antifungal activity was examined with an electrochemical method, cyclic voltammetry. 9-Methylacridine (MeAc), 9-ethylacridine (EtAc), 9-n-propylacridine (PrAc), 9-n-butylacridine (BtAc), 9-n-pentylacridine (PnAc), 9-n-hexylacridine (HxAc), 9-n-heptylacridine (HpAc) and 9-n-octylacridine (OcAc) were employed as the 9-straight chain alkylated acridine derivatives and Aspergillus niger was used as mold. The cyclic voltammograms (CVs) of the derivatives were measured using a mold-covered Pt plate electrode. The reversible redox current peaks due to the generation-disappearance of the anion radicals of the derivatives were observed in all the CVs. The adsorption current peaks significantly appeared in the CVs of PnAc. Furthermore, the reversible redox current peaks were directly proportional not to the square root of the scan rate, but to the scan rate. This meant that PnAc was adsorbed by the mold. Judging from the fact that PnAc has the highest antifungal activity, the adsorption of the 9-straight chain alkylated acridine derivatives to the mold was an important factor for the antifungal activity.

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Cultured tuna is becoming one of important fish sources in Japan, which is used to be imported by airplane without freezing from abroad. It gives a better economical profit and taste, and also promises a constant supply through out a year. However, there are few data available for the freshness of tuna undergoing such kind of transportation. This study was conducted to evaluate the initial freshness indicated as Kvalue of chilled-southern bluefin tuna (Thunnus maccoyii), imported by airplane from Australia, considering the difference of K value among parts of this fish body. The total amount of ATP and its related compounds was 11.82, 9. 74, 7.83 and 5.88, u moles/ g for dorsal (red), dorsal (white), tail and abdomen muscles, respecively. Tail muscle was showing the highest K value followed by dorsal (white), abdomen and dorsal (red) muscles, respectively. As tail muscle was more active among parts of fish body before fish was being caught, so that degradation of ATP was thought to occur faster in tail. It was confirmed that the quality of the sample fish imported by airplane was fairly good, which has K value ranged between 8. 8-14. 7%. The tail muscle could be regarded as a suitable part for analyzing K value.

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Changes of polyphenol oxidase (PPO, o-diphenol : oxygen oxidoreductase, EC. 1. 10.3. 1) activity of banana (Musa sapientum L.) fruits during ripening treatment with and without ethylene were determined. The total and soluble PPOs of pulp, which were extracted with and without detergent (Tween 80), were about 100 and 2 unit/g fresh weight, respectively. Both total and soluble pulp PPOs were remarkably increased and showed a maximun peak like a climacteric peak of respiration during the ethylene-ripening treatment. However, in the non-treated fruits, both total and soluble pulp PPOs changed a little during the treatment. In banana peel, total and soluble PPO were about 110 and 0.7 unit /g fresh weight, respectively. Both total and soluble PPO activities of peel were little affected by the ethylene-ripening treatment. These results suggested that the banana PPOs were mainly presented in pulp and peel as a “latent form”, and only “soluble pulp PPO” was affected by ethylene-ripening treatment.

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