Viscoelastic properties of cooked Japanese noodles made from wheat cultivars with low amylose contents (low-amylose type) were compared with those of noodles made from cultivars with normal amylose contents (conventional type). The noodles of low-amylose types showed lower storage modulus and loss modulus, and higher loss tangent than those of conventional types. Loss tangent was most strongly associated with amylose/amylopectin ratio among these three parameters. Dynamic viscoelasticity changes according to boiling time were compared between cv. Norin 61, a conventional type, and cv. Chikugoizumi, a low-amylose type. The noodles of Chikugoizumi boiled for 8min showed lower dynamic modulus than those of Norin 61 boiled for 20min, a standard boiling time. The water content of noodles was 65% for Chikugoizumi after 8-min boiling and 73% for Norin 61 after 20-min. The noodles boiled for such a short period seemed to be unsuitable for eating due to insufficient hydration of total starch. The results suggest that various parameters including dynamic viscoelasticity and water content should be considered to determine the suitable condition for quality evaluation of noodles of low-amylose type wheat.

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Tensile test, sensory evaluation, electromyography and masticatory pressure measurement of kelp snack were carried out in order to clarify the characteristics as a functional food for mastication training. Though no difference can be detected in breaking stress of kelp samples used in the present study, breaking force is different according to their thickness. In the sensory evaluation, it was judged that the samples with a high breaking force were difficult to masticate. In the electromyography, the sample judged difficult to masticate showed long mastication time, many number of chewing strokes, and high total muscle activity needed until swallowing. In the meantime, there was no significant difference among the samples in masticatory force, contact area, and masticatory pressure in the first chew. It is considered that mechanical characteristics of the samples with higher breaking stress than masticatory pressure influence total masticatory behavior but don't affect the first chew of human.

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Effect of oxygen content in green tea infusion and head space of can packed green tea infusion on L-ascorbic acid content, color and flavor changes of canned green tea drinks was investigated by comparing retort sterilization method with aseptic canning method. The decrease of oxygen content was correlated with the decrease of L-ascorbic acid content in green tea infusion during sterilization processing. The lower the content of oxygen was, the smaller the loss of L-ascorbic acid was. These effects were almost the same between the both processing methods. The color tone of green tea infusion changed noticeably on retort sterilization products compared aseptic canning products. The color changes of aseptic canned samples were mild and not concerned to the oxygen contents in green tea infusions. The flavor of canned green tea drinks were kept under the aseptic sterilization process. However, that of retort sterilized samples had an off-flavor, (retort-flavor). These results showed that the aseptic sterilization processing method was the best for the sterilization of canned green tea in terms of the low oxygen content owing to deoxygenation of extraction water and exclusion of head space volume of canned drink.

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In an attempt to develop functional foods, we produced oligosaccharide-rich bread for activation of the intestinal bacterial flora. There is no products like this type on the market because oligosaccharide is fermented by microorganism and digested, resulting in a decrease in its content. To overcome this problem, we produced croissants containing 3g lactosucrose (LS) per 36g of bread using the original species of "Panettone" that differs from the yeast used for daily distributed bread. After production of the product, HPLC analysis showed remaining of 1.81 (60%) of 3g LS. Thus, croissants containing high concentration of oligosaccharide could be produced. Bread as with polished rice is a principle food, and we are the first to develop bread containing hardly digestible oligosaccharide as a functional food for enhancement of excretion function. The oligosaccharide used in this test product was lactosucrose (LS). For the dough, Saccharomyces exiguus, Lactobacillus sanfrancisco, and Lactobacillus comoensis IP-5, which are original species of "Panettone", were used as microorganism. In addition, by using the method with the patent that makes the most of the characteristics of these microorganism croissants that keep for 1-2 months were obtained. Forty-three subjects (4 males and 39 females) ingested this croissant for 1 week, and the state of defecation was compared between before and after the ingestion period by a questionnaire. The frequency of defecation per week and the refreshing feeling after defecation improved significantly.

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Sensory evaluation by an expert panel and by a housewife panel was conducted to determine sensory characteristics of UHT milk processed at 140°C for 2 seconds by the indirect and direct heating methods. The effect of UHT processing on the physicochemical properties of milk was the greatest for plate-type pasteurization and less for infusion and injection in that order. Appropriate indicators for the heating degree were denaturation rate of whey proteins, rennetability and lactulose content. An evaluation of the sensory attributes and the principal component analysis of these attributes revealed that UHT milk processed by plate-type pasteurization provided thickness of body. Of the three types of UHT milk in the evaluation, this type was judged to be most unique in character. UHT milk processed by injection and infusion was judged to be thin in body and acceptable in other sensory attributes. The housewife panel judged the plate-type processed milk to have the best palatability.

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Potato tubers after storage at 5°C for 120 days were transferred to the incubators at 5, 20, and 33°C respectively, and their storages were continued for 70 days. Changes of sprouting state, fresh weight and content of several components of potatoes were determined at intervals during storage under various conditions. In potatoes stored at 5°C for 190 days continuously, sprouting and loss of fresh weight of them were not observed. Both total and reducing sugar content of potatoes increased rapidly, but ascorbic acid content decreased gradually during storage. In potatoes stored at 20°C after transferred from 5°C, sprouting occurred rapidly, and fresh weight, total and reducing sugar contents of them decreased. In potatoes stored at 33°C after transferred from 5°C, sprouting were inhibited and total sugar content increased, however reducing sugar content decreased rapidly during storage. Potatoes stored at 5°C were useless for potato chips because their appearance changed dark brown, while ones stored at 20 and 33°C can be used to make them well. In large-scale storage of potatoes at 33°C, the same physiological phenomena were shown as in laboratory-scale storage, although a few potatoes spoiled during large-scale one. These results suggest that the 33°C storage method is useful not only to preserve raw potatoes but to make potato chips.

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Dynamic and kinematic analyses for boiled potato straining processes of an experienced chef and an unskilled subject as well as a microscopic observation of these strained potatoes were performed. Straining process is represented as a repeating scrape motion of a wooden spatula against a sieve. A frequency of chef's repeating process was higher but the maximum resultant force of scraping for each cycle was smaller than those of the unskilled subject. Impulse for one cycle of the unskilled subject indicated more than three times of the chef's impulse, and for one gram processed potato its difference was more significant. This was also proved from a microscopic observation. Many of the cells of the potatoes processed by the unskilled subject were broken and its contents (starch) went out. From a kinematic analysis a lying angle of the chef's spatula became never less than ten degrees, while the spatula of the unskilled subject moved partially with a lying angle less than ten degrees. This was also a cause to give the potatoes unnecessary forces. In this experiment it was indicated that dynamic and kinematic analyses are effective methods for objective examination of cooking process.

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