The quantitative headspace gas chromatographic (GC) analysis on a coffee brew was developed as follows. Ten grams of coffee grounds were put into a 300ml headspace vessel, on to which 100 ml of boiling water was poured. Five μl of p-anisaldehyde was added as an internal standard. Both the extraction of coffee grounds and the trapping of headspace gas were carried out water bath maintained at 75°C. The headspace voltatiles of coffee brew were trapped into Tenax-GC column (φ3.5×90mm) during the passage (50ml/min) of 400ml of nitrogen. (1) The aromagram was composed of 43 peaks regardless of the kinds of coffee beans. The reproducibilities of main components ranged from 3.6 to 9.6%. (2) The aroma potencies of coffee volatiles were evaluated by dividing peak areas on a standard aromagram by the threshold peak areas estimated by "sniff-GLC", as well as the sensory characterizations of the volatiles were performed by "sniff-GLC" of coffee cup tester. (3) The GLC data could make clear the differences between Arabica and Robusta species but could not among Arabica species. The aroma potencies and characteristics of the volatiles were more important to evaluate the aroma of coffee brew.

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For the purpose of saving the labor cost to remove calyx from strawberry fruit (cv. 'America' for processing use), studies were carried on the cultivation of strawberry which facilitate the detachment of fruit leaving the calyxes on the vines, thus enabling to harvest the fruit by single hand. When gibberellin (5ppm GA3) was sprayed twice in April together with fungicide (Euparen) to protect gray mold disease, over 80% of calyx-free fruit was obtained by single hand harvesting even in the mid harvest season. The time required for calyx-removing process under these conditions was reduced to 23% of the conventional practice, and the time for fruit picking was also shortened considerably. Consequently, the overall process for calyx-removing and fruit picking reduced to 62% of the usual practice. Qualities of jam made from the strawberry thus prepared were comparable to the usual ones.

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To clarify the mechanism of the failure to remove calyxes, the torn strawberry was observed. In the fruit from which calyx was easily removed, marked differences in the tissue structure as well as the chemical composition were found between the pith and the part just under calyx. There were three categories of strawberries which failed to remove the calyx by single hand harvesting: fruit with only sepal, fruit with calyx and pedical and malformed fruit with calyx. The first category would be caused by the occurrence of the hollow between calyx and pulp. In the fruit of the second category, pedicel-detaching force was lower than calyx-detaching force. In the malformed fruit, insufficient changes in the tissue structure and chemical composition were found.

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Yolk, a mixture of yolk plasma and granule, and yolk plasma did not increase the volume of fermented dough when added to dough at the level of 3% of flour weight, however, these ingredients, especially plasma, increased specific volume of breads. Egg albumen or whole egg, added to dough at the same level as above, did not affect dough fermentation, however, oven spring of these doughs was depressed. Transmission electron microscopic observation of breads, sampled at the center of loaves, showed that yolk plasma formed membraneous structure in protein matrix and also around starch and yeast and the membrane might improve extensibility and/or gas-retaining property of dough during baking and increase loaf volume. The protein matrix of bread with yolk or yolk plasma contained inclusions type II of wheat endosperm less than those of control bread. The membranes might be formed by interaction between yolk lipoproteins and flour components, and/or between proteins and lipid-rich inclusions type II. Protein matrix bread with albumen was discontinuous and was often separated away from starch granules or gelatinized starch and consequently void spaces were observed around starch. The matrix and gelatinized starch contained more electron dense particles than those in control bread. Some of the particles might be condensed proteins of albumen. The ultrastructure of the matrix might decrease extensibility of the dough with albumen and make bread of poor volume.

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The melanoidin prepared from D-xylose and glycine was hydrogenated by hydrogen gas in the presence of Raney-Nickel as catalyst and antioxidative activity of this reaction product was investigated. Brown color of the melanoidin, when hydrogenated at 200°C, faded and antioxidative activity f the hydrogenated melanoidin also decreased. Fractionation of the melanoidin on Sephadex G-15 ave two peaks; high molecular melanoidin and low molecular reductone fractions. But these peaks isappeared in the hydrogenated melanoidins and these substances showed broad absorption spectra. hen antioxidative activity of each fraction was compared at same color level, strong antioxidative ctivity of the melanoidin was found in ranging from fraction No. 18 to 26, but the activities of the ydrogenated melanoidins (No. 2) and (No. 3) were distributed in ranging from fraction No. 22 to 31 nd fraction No. 27 to 34 respectively.

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Two distinct exo-polygalacturonases (exo-PGs) have been obtained from the culture filtrate of Aspergillus niger. The two exo-PGs were purified by CM-Sephadex C-50 column chromatography, Sephadex G-100 gel filtration, DEAE-Sephadex C-50 column chromatography and Sephadex G-75 gel filtration. The exo-PG I and II were purified approximately 15- and 25-fold, and they were found to have Km values of 20 and 3.85mg/ml, respectively, from the LINEWEAVER-BURK plot. The molec- ular weights of exo-PG I and II were 66000 and 63000, and had an isoelectric point of pH 5.6 and 3.8, respectively. The pH optima for exo-PG I and II were at pH 3.8 and 4.8. However, pH stability, optimum temperature and thermal stability of these enzymes were almost similar. The interesting feature of these enzymes is the activation by mercury ions. HgCl2 greatly activated exo-PG I but not exo-PG II.

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Acetoin, 2, 3-butanediol, acetic acid, propionic acid, iso-butyric acid, 2-methylbutyric acid and 3-methylbutyric acid in 34 samples of "natto" (fermentated soybean food by Bacillus natto) and 11 samples of "hikiwari-natto" (a variety of "natto" made of soybean grits) from 8 makers were deter- mined by gas chromatographic analysis. Neutral compounds were extracted by Extrelut pre-packed column 20 with methylacetate: ethyl alcohol (9:1) from the extract of "natto" with a cupric sulfate solution. Volatile acids were collected by steam distilation under acidic condition with tartaric acid from the extract. The extract efficiencies of volatile components were above 90% when prepared with these methods. The contents of those compounds were varied among the samples, and the ranges were 0-1646.5mg/100g (mean value, 319.5)in acetoin, 0-164.3 (38.1) in 2, 3-butanediol, 116.1-921.0 (378.0) in acetic acid, 1.5-14.2 (7.9) in propionic acid, 20.2-286.5 (123.5) in iso-butyric acid, 5.3-332.5 (104.4) in 2-methylbutyric acid, and trace-375.0 (77.0) in 3-methylbutyric acid on dry base, respectively. High positive correlation coefficients (up to 0.82) were observed between acetoin and 2, 3-butanediol contents, and among those of the three branched chain acids. 2-methylbutyric acid which newly detected in "natto" was identified as S-(+)-2-methylbutyric acid by the polarimetric analysis.

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For the purpose of utilization of "hatomugi" (soft-hull type of Job's Tears, Coix lacryma-jobi L. ma-yuen Stapf.), we investigated the extrusion cooking of it with a single-screw extruder. Dehull- ed grains used as material were composed of 13% of moisture, 12.9-14.1% of crude protein, 6.6-8.6% of crude fat and 1.4-2.3% of ash. Results obtained were as follows; (1) Snack foods were prepared from milled Job's Tears with an extruder, and sensory evaluation revealed that they were as tasty as extruded milled glutinous rice. (2) Appropriate conditions for extrusion were as follows; moisture content of the material was from 10 to 15%, milling degree was higher than 20%, outlet temperature of the extruder was about 160°C. (3) Suitability for extrusion cooking was markedly influenced by the kind of material. The lower the crude fat content of the material was, and the higher the viscosity of the material flour on amylography was, the better the result of extrusion cook- ing was. (4) In the case of inferior materials owing to high crude fat contents, the following methods were effective to improve them, (a) higher degree of milling of the material (b) defatting of the material by organic solvents (c) mixing with rice on extrusion.

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The relationship between coumarin and phenol contents and peroxidase activity and the food quality of the flours made from stored cassava roots was investigated. The food quality was determined by sensory evaluation of the non-fermented "puto" (steamed bread) samples made from the flours of three kinds of chips which were prepared from the healthy tissues of the cassava roots that were stored for 0, 10 and 20 days, respectively. The results have confirmed that the storage of the roots allowed the tissues to produce increasing amounts of the secondary metabolites and higher activity of peroxidase. Further, the results of the study established that the contents of the secondary metabolites and the activity of peroxidase in the flours from the stored cassava roots had the inverse correlation with the food quality of the flours, that is, some sensory parameters, especially general acceptability of the "puto" samples made from such flours.

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Almost all the orange pigment in the yellowish roots of cassava (cv. Golden Yellow) was indicated to be β-carotene. The content of β-carotene in the tissue was mostly in the range of 10 to 70μg per g dry weight, and was largest in the innermost part (C-part) per g dry weight, second in the intervening part (B-part, where PD occurred), and smallest in the outermost part (A-part). The content in the B- and C-parts decreased following the appearance and development of PD.

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The effect of the conditions of sponge dough mixing temperature, sponge dough fermentation time, dough mixing temperature and floor time during Japanese pastry production by the sugar added sponge dough method on sweet baked products were investigated using the experiment of orthogonal L3 design. By measuring pH of Japanese pastries, the maturity of dough of Japanese pastry could not be controlled. The organic acids in Japanese pastry was also produced during sponge dough stage. Any these fermentation conditions did not affect directly the specific volume of products. The dough of Japanese pastry was less stable than the dough of white bread. The dough mixing temperature and the floor time affected the amount of residual sugars in products. The added sucrose at dough mixing stage was scarcely concerned with the formation of organic acids. The sucrose in the dough was decomposed quickly to monosaccharides.

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