In previous paper, the experimental results of carbonyl compounds was described. This time, our attention was drawn to the compounds. with electrophilic nature which has tendency to attack the acidic parts of the cell wall. In the present study, we found that several compounds obtained from N-octyl-β-chlor ethylamine and N-dodecyl-urea, exhibit, markedly strong antimicrobial activities. Discussion was made in detail about pre paration, chemical structure and antimicrobial properties.
Sub-titled compounds are considered to belong to carbonyl compound as mentioned previously. Among them, one compound α-ethanolamino-β-benzoylpropionic-ethylester (K-330) has shown a remarkable antimicrobial activity in wide range of microorganisms, especially in the Hiochi-bacteria. Then, we took up these compounds newly and discussed in detail. As a result, K-330, Benzylamino, and Morpholino addition products proved to be suitable. Above all, K-330 excels in regard to acute toxicity, water solubility and stability. From I.R., U.V. and gas chromatogram, we proved that the chemical structure of K-330 is α-ethanolamino-β-benzoylpropionic-ethylester.
For the purpose of the simple and rapid determination of preservatives in foods, the combination method of the procedures of steam distillation and ultraviolet absorption spectra was studied. As the preservatives, five kinds of substances were taken up, namely benzoic acid (BA), p-hydroxybenzoic acid ester (PHBE), sorbic acid (SOA), dehydroacetic acid (DHA) and salicylic acid (SA). The steam distillation was done under the conditions of the addition of tartaric acid and magnesium sulfate or sodium chloride. The maximum wave lengths of each preservative in the aqueous solution at pH 2.0 were as follows: BA 230mμ, PHBE 255mμ, SOA 265mg, DHA 225mμ and 308mμ, SA 235mμ and 303mμ. In the case of the coexistence of the preservatives more than two kinds, the synthetic spectra of mixed preservatives are needed to be prepared previously. The interference by the scorch of the sample and the absorption appeared by the substances except preservatives were able to be almost excepted by the ether extraction of the distillate.
The colorimetric determination method of 2- (2-furyl) -3- (5-nitro-2-furyl) -acrylamide (abbreviated name: furylfuramide), the new preservative adopted as a food additive in Japan in 1965, in foods was tried and succeeded. As the sample, the fish sausage containing furylfuramide at the concentration of 20ppm was taken up. The principle of the determination bases on the fact that furylfuramide liberates nitrite ion on warming with sodium hydroxide in methanol or water, the color of which is developed by the usual way. The details of the procedure are as follows. (1) Weigh 10g of the sample containing furylfuramide. Add 5-10g of sodium chloride, 15-25ml of 5% m-phosphoric acid and 20ml (or 30ml) of the mixed solution of toluene and butyl acetate (1: 1), then homogenize and centrifuze. (2) Pour 10ml (or 15ml) of toluene and butyl acetate layer on Al2O3 column (6cm length and 1.5cm diameter). Wash with 20ml of n-hexane and then 20ml of ethyl ether. (3) Elute with 40ml of methanol (use 10ml of methanol each time and repeat four times). Take off about 4ml of the first eluate. (4) Collect 35-40ml of the eluate in the 50-ml brown-colored volumetric flask. (5) Add 1ml of 20% sodium hydroxide solution and warm at 50-55° in water bath for 50 minutes, then cool in ice water. (6) Add 2ml of sulfanilamide solution (2g of sulfanilamide are dissolved in 100ml of 20% hydrochloric acid) and stand for 15 minutes in ice water, then add 1ml of 0.1% N-naphthyl ethylenediamine dihydrochloride solution and stand for 30 minutes at room temperature. (7) Dilute the colored solution exactly to 50ml with methanol and determine the absorbance at 545mμ. Using these absorbances obtained calculate the concentration of furylfuramide in the sample. Concentration (ppm) =200×A/As×1/Weight of sample (g) A: Absorbance obtained from the sample As: Absorbance obtained from 5ppm furylfuramide standard solution
The present experiment was undertaken to elucidate the behavior of nitrofurazone in fish meat, because of the paucity of literatures related to the problem. Using the spores of Bacillus cereus var. mycoides ATCC 9634 as a test organism, the recovery rate of activity of nitrofurazone was estimated by the cylinder-plate assay method on fish meat after heat processing at 85°C for 30 minutes. The rate of recovery was found better in the fish with white-colored meat than those with red-colored one (Table 2). It was also noted that the activity of nitrofurazone was not decreased in water, buffer solution, carbohydrate, protein, and broth medium (Table 1). Experiment conducted on whale meat indicated that inactivation of nitrofurazone occurred when the heating temperature was raised over 70°C (Fig. 2). Addition of nitrite into red-colored meat of fish restored the activity of nitrofurazone which should be partly inactivated by heating in the system. Added nitrite probably react with Fe ion naturally contained in myoglobin and consequently loss of catalytic action of Fe ion may cause the regeneration of antibacterial activity (Table 3). From Table 4, the adsorption of nitrofurazone to the fish meat protein or a transfer of nitrofurazone to the oil in food will be little account for lowering recovery rate and the reducing substances formed in heating process may play a major part of this phenomenon.
The 86 commercial foods and 10 total diet samples collected in 1965 were analyzed for chlorinated organic pesticide residues by electron capture gas chromatography utilizing 2% DC 200, 2% DC 200+0.2% Epon 1001 and 2% XE-60 as the stationary phase. 1. The pesticide residues detected were BHC 0.023ppm, Dieldrin 0.002ppm, Endrin 0.003ppm, DDT and related compound 0.012ppm in non-fatty foods and BHC 0.171ppm, Dieldrin 0.037ppm, DDT and related compound 0.594ppm on basis of fat in fatty foods. 2. In total diet samples, the pesticide residues were detected at very low level and not differed on little amount from the findings in USA in 1963.