In order to investigate quality index of canned madarin oranges, carbonyl compounds were surveyed firstly. Two major spots were detected on a thin layer chromatogram from ether extracts. Then the ether extracts were converted to 2, 4-dinitrophenylhydrasone derivatives and separated on a silica gel plate. 5-Hydroxymethyl furfural and furfural were identified by ultraviolet and infrared spectra. 3-Deoxyglucosone and 3-deoxypentosone were identified similarly as ether insoluble carbonyl compounds.

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This study was designed to evaluate storage life from the behaviour of carbonyl compounds of canned mandarin oranges during storage. The results of thin-layer chromatograph- densitometric tracing showed that the percentage of 5-hydroxymethyl furfural (HMF) increased during storage. Therefore, HMF content as an index for quality was determined by p-toluidine/barbituric acid colourimetry. The content increased during storage especially at higher temperature and correlated well with organoleptic evaluation. Samples contained HMF above 5mg (%) gave low organoleptic. In commercial products, such high level of HMF was achieved after 3 to 5 years storage.

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The presences of furfural and 5-hydroxymethylfurfural in darkend tomato products were confirmed. The furfurals were characterized as the anti-forms of 2, 4-dinitrophenylhydrazone derivatives.
Furfurals were extracted from the sample with ether and separated into furfural and 5-hydroxymethylfurfural by steam distillation. Furfurals were derived into hydrazones in the usual manner. Each hydrazone derivative was purified by column chromatography on acid alumina with benzene-ethyl acetate as eluent, respectively and recrystallized from ethanol-ethyl acetate. UV and IR data of purified hydrazones were identical with those of the authentic samples.

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Effects of xylose on the dried agar jelly were examined. When agar gel contained xylose, its muximum ultimate strength was recognized at the concentration of about 50% xylose. When agar solution containing 50% sugar was boiled for 2hr., the ultimate strength of gel was slightly changed by sucrose and xylit, but decreased to the negligible value by xylose. At the same time, drop in pH value and increase of browning color were observed by use of xylose. The gel formation ability of agar that was once reduced with addition of xylose could not be recovered when xylose of agar gel was washed off. Decrease of the ultimate strength and drop in pH value of agar gel added 50% xylose were prevented consisderably by use of the buffer solution. From these results, the decrease of the ultimate strength was considered to be caused by the low pH value which was due to the added xylose. The ultimate strength of agar jelly contained xylose and corn syrup was little affected in the condensing process of the jelly. The drying rate of agar jelly contained corn syrup and xylose or xylit at 60°C was more accelerated under the low humidity but was more delayed under the high humidity than that of sucrose jelly.

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Effects of salts on the emulsifying properties of whole yolk and yolk proteins in the watercotton seed oil system were investigated. The results are as follows:
1) HLB of egg yolk obtained from the spreading coefficient was 12.4.
2) The strength of emulsion stabilizing power of yolk protein fractions were in the order of phosvitin-lipovitellin fraction (PvLv)>water soluble fraction (WSF)>low-density fraction of granule (LDFG)>low-density fraction.
3) The stability of emulsion by yolk and yolk protein fractions changed due to salt concentration, and had a peak at 0.025-0.1 M of NaCl. Yolk, PvLv and Lv had another peak of stability at 0.2-0.4 M of NaCl.
4) CaCl₂ had a lower stabilizing ability than NaCl, and NaSCN had as high stabilizing ability in a lower concentration as NaCl.
5) The interfacial tension and viscosity of the emulsions by yolk protein fractions decreased in the order of PvLv>LDFG>LDF>Livetin, but did not agree with their emulsion stabilizing power.

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Wasanbo-to is defined as an old type of refined sugar by the traditional procedure. The principal procedure for refining is based on the fact that impurities would mainly be absorbed on surface of crystals and easily removable by polishing with water. Each step of the purification and final preparations were analyzed. Besides sucrose, trace amount of glucose and fructose was detected by paper chromatography and the both sugars were assayed enzymatically with glucose oxidase-peroxidase and D-mannitol dehydrogenase, respectively. During refining procedure, glucose, fructose and ashes were gradually decreased. Analyses of final preparations were as follows: moisture, 0.30-0.81%; sucrose, 94.8-99.3%; glucose, 0.13-0.44%; fructose, 0.20-0.68%; and ashes, 0.38-0.74%. Calcium, magnesium, sodium and trace amount of silica, iron, cupper and aluminium were detected in each ash.

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Antibacterial substances in hot-water extract (110°C, 15min) of a green tea product was investigated. The experimental results obtained were as follows.
1. Antibacterial effects of the green tea extract appeared to be conspicuous on Vibrio metschnikovii and Alcaligenes faecalis. These bacteria were found to be about ten-times as sensitive as Staphylococcus aureus to the extract.
2. The green tea extract was adsorbed to casein and the tannin fraction, which showed antibacterial effects, was eluted from the adsorbent with 90% aq. acetone. Five catechins were separated from the tannin fraction by paper chromatography and their contents were quantitatively determined. The minimum inhibitory concentrations (mcg/ml) of these catechins on V. metschnikovii were: epigallocatechin 20, epigallocatechin gallate 45, epicatechin gallate 45, gallocatechin 50, and epicatechin 75.
3. Addition of caffeine at a concentration of approx. 1mg/ml showed a marked synergetic effect to increase the antibacterial titre of catechins (ca. 4mg/ml). However, caffeine itself (2mg/ml) had no antibacterial action.
4. An aqueous solution containing the above five catechins and caffeine at the same concentrations as in the green tea extract showed a similar antibacterial titre to that of the extract.

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The constituents of the organic acids in Nozawanazuke (fresh and after one year's) was determined by gas chromatography as butyl ester after batchwise ether extraction using celite and anhydrous sodium sulfate. The content of the organic acids in 100g of sample was as follow: fresh; formic 1.8mg, acetic 3.2mg, Iactic 0.8mg, succinic 17.2mg, malic 26.2mg, and citric acid 5.0mg., one year's old; formic 2.8mg, acetic 21.8mg, lactic 212.6mg, glycolic 1.2mg, succinic 6.6mg, and malic acid 1.0mg. The content of formic, acetic, lactic and glycolic acid increased during one year's storage and high amount of acetic and lactic acid which were not detected in fresh, were found.

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