Effects of metal chelating agents and metal ions on the volatile substances of cooked chicken were examined by chemical analysis and a sensory test. The addition of Na-tripolyphosphate (NaTPP) to chicken meat increased the amount of H₂S among vola tiles evolved during cooking, but decreased that of volatile carbonyl compounds (VCC). This treatment enhanced a cooked chicken flavor. It was recognized that the increase in H₂S evolution was caused by the rise of pH value. On the contrary, cupric ion produced a negative effect on the production of chicken flavor, and this addition increased VCC and thiovarbituric acid value. Other metal chelating agents such as citric acid, phytic acid and EDTA, provided the same results as Na-TPP. It was supposed that these phenomena were attributable to the chelating action to metal prooxidant in chicken meat. It could be concluded that a proper evolution of H2S and a protection against lipid oxidation during cooking were important to produce an excellent chicken flavor.

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Setagaya-ku, Tokyo 156 The gradual changing pattern of lightness (L), saturation color index and ΔE during storage of unblanched and blanched banana slices were found to conform to heat inactivation performances of peroxidase isozymes and polyphenoloxidase fractions. At 10min steam blanching of the slices all the isozymes of peroxidase were inactivated, whereas, at 5min blanching polyphenoloxidase were completely inactivated; and the inactivation time and rate of each isozyme and fraction were found to be different until being completely inactivated, although 90-96% of the peroxidase activity and 99% of polyphenoloxidase activity were lost at 1min blanching. To clarify this inactivation pattern the D-values for peroxidase isozymes and polyphenoloxidase fractions were calculated. All the fractions of pectinesterase exhibited zero residual activity at 10min blanching and the order of heat stability was found to be fraction-III>fraction-I>fraction-II at 30s blanching, at 1-4min blanching it was fraction-II>fraction-III>fraction-I and after that the order was fraction-II>fraction-III>fraction-I. After one minute of blanching only 66.3% of fraction-I, 55.4% of fraction-II and 30.3% of fraction-III were inactivated and during 6min blanching 96.4%, 82.7% and 91.8% activityies of the respective fractions were lost. Hardness were positively correlated with the pectinesterase activity and with the pectin behavior of versene and HCl-soluble fractions both in terms of pectin and methoxyl content of the fractions. There was an increase of water soluble pectin and its methoxyl content with the increase of blanching time, whereas, these values decreased in versene and HCl-soluble fractions. There was no remarkable change in phenolic content and acidity values.

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Stability of allyl isothiocyanate (Allyl NCS) in aqueous methanol was studied by calculating the peak areas of allyl NCS and methyl allyl thiocarbamate on gas chromatogram. Allyl NCS gradually degradated in methanol and water, while it was stable in n-hexane, acetone and ethyl acetate. Degradation was sensitive to temperature and pH: It was accelerated at high temperature (37°C) than at low temperature (0°C). It was stable at -5, -18°C. The degradation was promoted in alkaline side than that in acidic side. Light had nothing to do with the degradation. Citric acid, sugar ester and salada oil controled the degradation and their effect was proportional to their concentrations.

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A high-performance liquid chromatographic (HPLC) method for determining free sugars (glucose, fructose, sucrose, raffinose and stachyose) in green tea was investigated. A used column was Shodex Ionpak S-801, and a mobile phase was water. A refractive index detector was used for the detection of free sugars. Column temperature of 60°C and flow rate of the mobile phase of 0.5ml/min gave the best result for the separation of 5 free sugars, and xylitol was found to be the best compound for an internal standard. The preparation of free sugars from green tea was as follows; Four mg of xylitol was added to about 300mg of green tea, and its free sugars were extracted with 50ml of hot water for 15min in boiling water. The solution was passed through columns of Amberlite IRA-45 (15ml) ion exchange resin. The columns were washed with 100ml of water. The elute was concentrated to about 5ml and filtered through 0.45μm filter. This method will ensure the determination of free sugars in green tea with 1.80-11.51% of coefficients of varience and 99.2-102.1% of recovery.

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(1) The increase of [¹⁴C] glucose incorporation from ADP-[¹⁴C] glucose into 7M urea-treated starch was observed, and that from UDP-[¹⁴C] glucose was significant in 5M urea-treated starch. (2) Search for the fate of the incorporated glucose into intact starch granules revealed that [¹⁴C] glucose from radioactive ADP-glucose was found mainly in the outer layer of granules which was insoluble in 10M urea. On the other hand, radioactivity from UDP-[¹⁴C] glucose was incorporated into both the inner (urea soluble fraction) and the outer layer. (3) Soluble fraction after pullulanase treatment of 7M urea treated starch incorporated [¹⁴C] glucose into ethanolprecipitated fraction from UDP-]¹⁴C] glucose, not from ADP-[¹⁴C] glucose. (4) These findings indicate that starch synthetase bound to starch granules toward ADP-glucose is localized in a starch granule, and starch synthetase toward UDP-glucose was solubilized by urea/pullulanase treatment of starch granules.

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Bacterial determinations were made on the coating crumbs of 60 raw frozen foods for frying. The bacterial count in 32 samples was in the order of 10³/g, and that of 13 samples was more than 10⁴/g. The major bacteria were gram positive spore forming rods (Bacillus spp.) and gram positive cocci. The former was detected in 51, and the latter in 55 out of 60 samples. Among 151 Bacillus spp. isolated, two predominant species consisting of 55% B. subtilis and 25% B. licheniformis were found. Besides, a few strains of B. cereus, B. sphaericus and B. megaterium were isolated. After frying at 170°C, Bacillus spp. constituted the only bacterial flora in the fried foods, which increased from 1010² to 10⁵/g in 24 hours at 25°C.

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Lecithin did not have influence on hardness of the gels prepared from whole soybean, defatted soybean and 11S protein. This finding suggest that the effect of polar lipid on the texture is marked in these multicomponent systems. The hardness of soybean protein gels increased with the increase of added palm oil up to 3.5% and was almost constant above it. Sodium caseinate hardened the gel linearly with its content, while dextrin decreased its hardness linearly with its content. Hardness value calculated by adding the values obtained for each gel prepared by adding three main components of powdered palm oil did not coinside to the determined value of the gel prepared by adding whole powdered palm oil.

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