The historical background of “balut” and “penoy”, boiled fertilized and unfertilized incubated duck eggs, respectively, was investigated and some chemical aspects of this egg product were studied. Samples were commercial boiled incubated fertilized (“balut”) and unfertilized (“penoy”) eggs from the Philippines and eggs purchased in Japan and incubated in the university laboratory. Result of the search revealed that “balut” and “penoy” making is not native to the Philippines. Chinese traders and migrants have brought the idea of eating fertilized duck eggs to the Philippines around the 17^th century. However, the knowledge and craft of balut-making has been localized by the “balut” makers (mangbabalut). To date, “balut” production has not been mechanized in favor of the traditional production by hand. The total FAA content of the incubated samples was higher than that of the non-incubated samples. Taurine significantly increased in both the unfertilized and fertilized samples, thus has a positive impact on the nutritive value of the product. It was observed that after boiling, a large amount of drip was present in the whole incubated fertilized eggs, less in the unfertilized and hardly any in the non-incubated ones.

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Changes in the DPPH radical-scavenging activity and related components during processing of the traditional fermented soybean food, Daitokuji-natto, made in Zuihoin Daitokuji (Kyoto) were examined. Daitokuji-natto was processed from the end of July to September. The contents of genistin, daidzin and glycitin in soybean (Tsuruhime harvested in Hokaido) were all increased by steaming. However, the contents of these components gradually decreased during fermentation and maturation, in contrast to the increases of the daidzein, genisitein and glycitein contents. Fermentation for 1 week in a cellar resulted in the contents of peptides and free amino acids, especially glutamate, being increased by enzymatic degradation of the protein. The melanoidin-related compounds gradually increased during the progress of maturation under sunlight in the summer for 2 months. Although the DPPH radical-scavenging activity was significantly related to the polyphenol contents (p<0.01), the components mainly responsible for the radical-scavenging activity of Daitokuji-natto were found to be melanoidin-related compounds.

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The effects of taste substances on the syneresis of cornstarch pastes were studied by a centrifugation method. The concentration of cornstarch was fixed at 3.0 wt%, and sucrose (0-50 wt%), sodium chloride (0-25 wt%), citric acid (pH 6.3-3.0), caffeine (0-2.7 wt%) and sodium L-glutamate (0-18 wt%) were added in a wide concentration range. The degree of syneresis for the cornstarch pastes in the range of 10-20 wt% of added sucrose was decreased because of the increased size of the starch granules. Moreover, no syneresis occurred for the paste with 25 wt% sodium chloride and the paste with citric acid at pH 3.0. This indicates that many amylose and amylopectin chains were leached out from the starch granules and formed entangled networks. However, these results were exceptions, and the degree of syneresis for the other pastes with added taste substances reached about 23% after 45 days of storage at 5°C. This value was the same as that for the cornstarch paste without any added taste substance. No marked effects on the syneresis of cornstarch pastes were thus apparent by adding taste substances.

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The vitamin C (VC) content and 1,1-dipheny1-2-picrylhydrazyl (DPPH) radical-scavenging activity of sweet potato were lower immediately after cooking, but the residual value after vacuum cooking and storage were higher than those after boiling, while the polyphenol content remained unchanged. The loss in VC content and DPPH radical-scavenging activity of sweet potato was significantly suppressed by the addition of sugar with both cooking methods, but was promoted by soy sauce with the vacuum cooking of Japanese radish and taro. While the DPPH radical-scavenging activity of sweet potato was mainly correlated with the amount of ascorbic acid, that of Japanese radish and taro was mainly correlated with the polyphenol content. Vacuum-cooked potatoes were preferred overall to the boiled variety, while the texture of boiled Japanese radish was preferred to that of the vacuumcooked type.

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In preparation of fruit liqueur, the effects of freezing pretreatment on the dissolution of ascorbic acid and polyphenol from the fruits to the liquor were examined. The freezing pretreatment of lemon and kiwifruit soaked in a 1iquor containing 35% alcohol at-20°C for 24 h and allowed to stand at 20°C for 4 days did not enhance the dissolution of components such as ascorbic acid and polyphenol. About 70% of the ascorbic acid in fruits remained in the liquor after soaking for 4 days. Addition of sugar to the fruit in the liquor pretreated with freezing suppressed the dissolution of ascorbic acid and polyphenol. Both soaking in alcohol and freezing pretreatment resulted in lower impedance values and disappearance of a Cole-Cole plot, suggesting serious damage to the cell structure of 1cubic cm of apple sample. Especially, the Cole-Cole plot completely disappeared after 3 h soaking when the fruit was soaked in 35% alcohol. It was suggested that alcohol affected mainly the dissolution of the fruit components.

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The butter test was devised for comparing the energy consumption of wet and dry cooking methods by measuring the energy consumed until the butter became solid.
The energy consumed increased with increasing sample weight, and it was clarified that if the energy consumed by a microwave oven is set to 1, the equivalent figures are 2.8-3.6 for a steamer and 4.7-6.1 for a gas oven.
It was found that the time with each heating method for the butter to solidify corresponded with the rate of temperature rise and was similar to the rate of softening of potato. This proposed test method is more convenient, versatile, and consistent than the conventional test methods of boiling and actual cooking.

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