[in Japanese]

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In this paper we have studied about the in-take and influence of food preservatives to Chlorella life cycle, using amino acids as the measure to discern in the test of title and the followings were obtained:
1) We allowed to stand both test and blind culture solutions at room temperature under the exposure of 40W white fluorescent lamp, adding Chlorella to the test and the control Arnon medium which was previously adjusted to pH 5. The medium contained one of the following amino acids; L-Val, L-Ileu, L-Lys, L-Met, L-Try and L-Phe. During cultivation, the amount of residual amino acids was estimated at 0, 24, 48, 72, 96 and 120hrs. by Yemm-Cocking's ninhydrin colorimetry and calculated the in-take ratio. After incubation for 48hrs, the in-take ratio reached to maximum, suggesting that the saturation phenomenon occurred. The maximum in-take ratio were about 90% for Phe, Try, 50% for Lys, 40% for Ileu and 20% for Val, Met.
2) At the same time, we have tried to get the in-take ratio of each amino acid in the presence of food preservatives, under the same experimental conditions as mentioned above. The following food preservatives were tested: Sodium benzoate, Salicylic acid, Potassium sorbate, p-Hydroxybenzoic acid and Ethyl p-hydroxybenzoate. After incubation, each medium was centrifuged to remove microbes. Thus, in the resulting supernatant, the amounts of residual amino acids were estimated to calculate in-take ratio after 0 or 72hrs, and to measure the inhibition ratio of amino acid in-take by these food preservatives. In general, food preservatives showed a strong inhibition toward the in-take of Ileu, Phe, Met, Lys and the extent of inhibition was as follows; the Ethyl p-hydroxybenzoate>Potassium sorbate>Sodium benzoate>Salicylic acid>p-Hydroxybenzoic acid.

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Application of a hydroxamate method was suggested by Bassette and Keeney for the detection of foreign fat in milk fat.
This method does not require the saponification of milk fat as is the case with the determination of Reichert-Meissl-Wollny and Polenske values and butyric acid number (Buttersäurezahl).
Application of this method for the detection of the adulteration of milk fat was undertaken, by use of butterfats extracted from butter, butter oil, ghee, cream, ice cream mix and ice cream produced in Japan as the test sample, comparing the results with those obtained by the gas chromatography of sterols, RMW, Pol and butyric acid number. HAI of pure milk fat was defined within the range of 9.8-12.5.
It was demonstrated that the results of discrimination carried out by HAI were not always coincident with those obtained by gas chromatography of sterols. This indicates that commercial milk fats are available in Japan to which regulation of butyric (and caproic) acid has been carried out, and that results obtained by sterol test are not absolute. The correlation coefficient between HAI and butyric acid number was calculated to be 0.92. Distillation as well as saponification are necessary for the determination of RMW, Pol and butyric acid number. These tedious procedures are excluded in the determination of HAI, eliminating the error of determination. German National Committee of IDF expressed that HAI method is being adopted as the tentative method for the discrimination of adulteration of milk fat. It is recommended, therefore, to carry out both HAI and sterol tests for the detection of foreign fat in milk fat.

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Thirty-two commercial honeys and honeys, supplied directly from beekeepers, were deproteinized by the addition of Carrez solutions, then the filtrates were subjected for ultraviolet spectrometry. Absorbances (E) at 245, 284, 285 and 325mμ were read for each honey, the 5-hydroxymethylfurfral (HMF) contents being calculated by the two methods (The methods will be called, hereafter, two points U. V. method and three points U. V. method, respectively).
a: by use of E₂₈₄-E₂₄₅
b: by use of E₂₈₅-0.5 (E₂₄₅+F₃₂₅)
HMF contents were also determined for the above-mentioned honeys by the colorimetry through the reaction of p-toluidine-barbituric acid.
There were close correlations between the HMF contents in honey estimated by the three methods, the correlation coefficients between the colorimetric results and 2 points or 3 points U. V. spectrometric results being 0.992 and 0.989, respectively.
Usually, somewhat higher results were obtained by the U. V. spectrometries than by the colorimetry. It is presumed that these differences might be attributed to the varieties of fururals contained in honey, since the methods applied were not specific for HMF only. It is provided in the Draft Provisional Standard for Honey (Joint FAO/WHO Food Standards Program) that HMF contents in honey, estimated by the p-toluidine-barbituric acid colorimetry, should not be more than 40mg/kg(4.0mg%), while it is shown in the domestic standard, that HMF contents determined by use of either the colorimetry or 3 points U. V. spectrometry must not exceed 5.0mg%. It was noted in this report, that there might happen discrepancy in the judgement, for the borderline cases of honey, when the two domestic methods were applied for the determination of HMF. It is difficult, at the present state, to conclude which of the three methods is most suitable for the estimation of HMF in honey. Promising results were obtained through direct U. V. spectrometry of honey in a 0.02cm super-thin cell by use of Shimadzu MPS-50L Multipurpose Recording Spectrophotometer. This apparatus is epecially contrived for measuring the absorbance or attenuance of opaque samples, using end-on type photomultiplication system. The troublesome procedures of dilution as well as deproteinization are omissible by use of this apparatus. The presence of small quantity of protein (from 0.04-0.22% in domestic honeys) makes no obstacle for the direct determination of HMF.

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The photosensitizing action of food dye on biological system has been examined using various kinds of bacteria. Flavobacterium aquatile IAM 1310 was the most suitable bacteria for the detection of photodynamic action of dye. Using this system, it was found that among 22 dyes including food dyes and other synthetic dyes, Erythrosine, Eosine, Phloxine, Rose bengal, Methylene blue and Rhodamine B have strong lethal effects on Flavobacterium aquatile in the presence of visible light.

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A method for the atomic absorption spectroscopic determination of cadmium extracted with the APDC (ammonium pyrrolidinedithiocarbamate)-MIBA (methyl isobutyl ketone) is described. We examined various condition of the extraction of cadmium and of the atomic absorption analysis.
Cadmium was efficiently extracted from the aqueous solution adjusted to the pH 3.5-10.3 range and to the salt concentration over 2.5M with saturated ammonium sulfate solution. Under these conditions, cadmium in 25ml of the aqueous solution was completely extracted with 10ml of MIBK by a single extraction. When the aqueous solution increased to 50ml, the extractability was still 97 per cent.
The presence of a large amount of zinc, lead and mangane decreased the absorbance of cadmium owing to the poor solubililties of APDC-chelates in MIBK.

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