Aroma components of 50% inverted liquid sugar heated at 120°C for 10 minutes was compared with those heated for 30 minutes at same temperature by GC-MS, The former aroma consisted of a small mumber of compounds including isomaltol and maltol which gave better flavor than the latter. The latter flavor consisted of many compounds related to burning and stimulating odor, and bitter taste. The above off-fiavor compound increased remarkably along the reduction content of 5-hydroxymethylfurfural. Consequently, with the purpose to produce acceptable liquid sugar, the heat treatment should be stopped when maltol compounds content is reached above 10ppm, and relative content of 5-hydroxymethylfurfural is reached maximum level.

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Stress relaxation tests were carried out on agarose, gelatin (the alkaline process and the acid process) and konjak mannan gels by using a chainomatic balance relaxometer to investigate the influence of pH on the rheological properties of these gels. The gels with various pH values ranging from 1.5 to 12.5 were prepared. The stress relaxation curves were analyzed using a six element mechanical model consisting of three Maxwell element in parallel. Ultrasonic attenuation of gelatin and agarose was determined by pulse method to investigate the change occured by the sol-gel transformation of these gels. The elastic modulus E1 of Maxwell element with the longest relaxation time τ1, which is supposed to correspond to the main network structure in these gels, were nearly constant through the pH range from about 5 to 9. The sharp decrease in E1 were observed in lower and higher pH values. Magnitude of E1 of konjak mannan gels increased with increase of pH up to 11.3-12.6. The apparent activation energy for τ1 were maintained to be about 5-9kcal/mol within the range, which was nearly equal to that for the neutral of agarose and gelatin gels.

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Changes in biological, chemical and organoleptic properties of brown rice and milled rice stored in package pouches were investigated as functions of storage temperature, moisture content and packaging film. The major factor affecting the quality change in polyethylene packed rice was related to its moisture content. In summer time, maximum allowable storage time of the rice was 40-50 days at 15.5% of moisture content and less than 20 days at 16.6% of moisture content. To assure the long-term storage, the moisture content had to be lowered to below 14.5%. When the polyethylene packed rice containing 15.5-16.5% of moisture content was stored at 25°C, fungi capable to grow were the species of Asp. glaucus and Asp. restrictus group but other storage fungi could not grow. The brown rice containing less than 14.5% of moisture content did not show the change in fungous populations, after the storage for 150 days. Packages made of materials with low permeability to gases inhibited the growth of storage fungi on the packed rice, permitting the rapid consumption of in-package oxygen. In storage changes in levels of fat acidity and reducing sugar occured in the same mode regardless of the packaging materials. It was indicated that when the rice containing 16.0% of moisture content was packed in PVDC/PT·PE, three months of storage was allowable at 25°C.

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The electrochemical method developed for measuring organic acid contents in foods was applied to the water-pyridine solvent system. If the concentration of pyridine was below 20% (v/v), plots of organic acid content vs. measured conductance gave straight line. This fact agreed with the theory of the analytical method. By studying the conductance of strong electrolyte and that of organic acid in solvent mixtures, it was found that 10% (v/v) pyridine was best for analysis. Concentration of hydrogen ion measured by this improved method corresponds to all of the possible hydrogen ion measured by alkalimetry. All of the major organic acids observed in foods gave better linear plots in water-pyridine solvent system than in water. The slopes of linear line was dependent on the basicity and the ionic equivalent conductance of anion. The slops obtained in three organic acids; tartaric acid, malic acid and succinic acid were almost equal. In application of this improved method to the commercial beverage containing citrus juice, high precision was obtained.

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The effects of three kinds of commercial distilled monoglycerides of hardened beef tallow, beef tallow and safflower oil on the creaming and water-sorption qualities of edible solid fats were investigated. The creaming value of the edible fats was increased with the addition of monoglycerides and its effects differed depending on the kind of monoglyceride added. Safflower monoglyceride increased most remarkably followed by hardened beef tallow monoglyceride and beef tallow monoglyceride in this order. Effect of tempering was most remarkable in the hardened whale oil added with safflower monoglyceride. The water-sorption index was increased with the amount of added onoglyceride, and its effect also differed markedly depending on the kind of monoglyceride gave most remarkable effect followed by beef monoglyceride and hardened beef tallow monoglyceride in this order. Water-sorption index was not markedly affected by the tempering. The increase of creaming value and water-sorption index seemed to be caused by the change in the properties of crystalline substances in the solid fat, which differed among the monoglycerides employed in this examination.

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Investigation on the conditions of quantitative determination of isothiocyanates in the hydrolysates of mustard flour, "Wasabi" powder and horseradish flour was carried out by both head-space technique and GADAMER's method. The order of allyl isothiocyanate contents determined by head-space technique were mustard<"Wasabi" powder<horseradish. However, the order determined by GADAMER's method were quite the reverse as follows: mustard>"Wasabi" powder>horseradish. Hydrolysis of the samples in GADAMER's method was sufficient at 45°C for 5min. Distribution ratios of volatile components in the hydrolysates of these materials by head-space technique were different from those determined by direct injection of ether extract of distillate.

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Quantitative determination methods of biliproteins including allophycocyanin, phycocyanin and phycoerythrin in the dried laver (Porphyra yezoensis) were studied. When the laver was homogenized in a mortar with a pestle for two to three minutes, biliproteins were much effectively extracted into phosphate buffer. Two days at 5°C was adopted as the extraction period of the proteins. The protein contents were calculated by measuring the absorbance of the buffer solution at 650, 615 and 563nm. This method was superior to the conventional methods because of the simplified procedure, shortterm extraction period, small amounts of sample required and the highest recovery of the pigments. Amongst several lavers that were commercially available, maximum biliprotein contents were observed in the laver of the highest-grade, followed by intermediate- and low-grade in the decreasing order.

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Using mixed milk, 40 samples, from some selected dairy plants in Miyazaki prefecture, physical properties (hardness, breaking energy and elastic modulus) of rennet curd were measured with rheometer. From results obtained, physical properties of rennet curd were significantly different among milk samples. Furthermore, significant positive correlation among these three parameters were found.

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Two grams of corn, potato, wheat, waxy maize and waxy rice starches or waxy rice flour were mixed with 1.6ml of an aqueous solution of nicotinamide (NA), containing various amount of NA up to 1.6g Per 100g of the starch or flour and then heated. The resultant paste was stored at 2°C. The change in hardness of the paste was followed by measuring the gel strength by means of a curd meter. As a result, it was found that the addition of NA caused the decrease of the gel strength of the paste in proportion to the gel strength of the pastes without NA; the addition of NA to the paste of the less gel strength gave the lower value of the relative gel strength which was defined as the percentage of the gel strength of the NA-containing paste to that of the corresponding paste without NA.

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