@misc{oai:niigata-u.repo.nii.ac.jp:00004438,
 author = {佐藤, 恵美子},
 month = {Sep},
 note = {The starch is a kind of carbohydrate which is produced by photosynthesis in the plant,and is stored as starch grain in a seed,a tuberous root and a tuber. Starchy foods mean food product processed by cooking,when we use these storage organ as foodstuff for cooking. The starchy foods have important role on provisions origin from ancient time for human being,and they contain carbohydrates more than 80% as unhydrous matter. The changes in the gelatinization and retrogradation of starchy foods occur with cooking time and storage commonly. In this paper,changes in the chemical and physical property of Cooked rice,Gomatofu and Retrograded Dango as the starchy foods with cooking time (preparing conditions) and storage (storage time and temperature) were investigated. Further,relation between science of good taste of starchy foods and the chemical properties (flavor) and the physical properties (appearance and texture) were discussed.1. Changes in Surface Color,Texture and Flavor of Rice during Cooking (Part 1). Change in Volatile Components and Volatile Carbonyls during Rice Cooking　The relationship between the flavor and the heating time of rice (Koshihikari and Reimei) was examined by sensory evaluation. The rice was heated in an oil bath as reported previously. Volatile components in the head space vapor (HSV) of cooked rice were investigated by GLC. Further,volatile carbonyl compounds from unheated and heated rice were converted into 2,4-dinitrophenylhydrazone derivatives,which were determined by TLC,UV,spectrophotometry and GLC. The relationship between these analysis and sensory evaluation was discussed. The following results were obtained : after heating the rice for 20 min,volatile components in the HSV were the largest in quantity,but the flavor of rice heated for 30 min was the most desirable in the sensory test. The results of GLC in the HSV indicated the existence of paraffins (C_<5. 6. 11>),n-aldehydes (C_<2-7>),branched aldehydes (C_<4. 5>),n-alcohols (C_<1-3. 5>),acetone,ethanethiol,3-methyl- 1-butanethiol and dimethyl sulfide. The volatile carbonyl compounds of the rice were identified as follows : n-aldehydes (C_<1-9>),branched aldehydes (C_<4-5>),2-ketones (C_<3. 4. 6>),furfural and benzaldehyde. The quantity of volatile carbonyl compounds of the rice heated in a closed container was about twice as much as the unheated rice and 42.9% of that of the rice heated in an open container moved into distillate. In the sensory test,the flavor of rice heated in an open container was significantly more desirable than that of the rice heated in a closed container,because tile undesirable volatile components,such as pentanal and hexanal,decreased during cooking in an open container., 2. Changes in Surface Color, Texture and Flavor of Rice during Cooking (Part 2) Volatile Acids of Cooked Rice　Identification and comparison of the volatile acids obtained from the vaccum-distillates of rice which was cooked in a closed container, and odor evaluation tests were carried out. The vaccum-distillates were concentrated at pH 10 and butylated with 1-burtanol, cone. sulfuric acid and anhydrous sodium sulfate, then were subjected to GLC and GC-MS. Twenty-one volatile acids as 1-butyl ester were identified in the rice cooked in closed container and an open container as follows: straight aliphatic acids (C_<1-18>), branched aliphatic acids (C_<4-6>), benzoic acid, 2-hexenoic acid and levulinic acid. Among them, newly identified compounds were as follows : straight aliphatic acids (C_<1-5>), branched aliphatic acids (C_<4-6>), benzoic acid, 2-hexenoic acid and levulinic acids. About a quarter of the quantity of volatile acids were distilled off by the cooking in an open container. In the sensory test, the order of rice cooked in an open container was significantly more desirable than that of rice cooked in a closed container, because the undesirable volatile components as lower molecular fatty acids decreased during cooking in an open container. 3. Changes in Surface Color, Texture and Flavor of Rice during Cooking (Part 3) Surface Color, Texture and Gelatinization Degree Experiment were carried out to investigate the change of surface color, texture, and gelatination degree of starch of the rice which was heated in oil bath of 150°± 1℃ for 40 min, and then the rice was divided into upper, .middle and lower parts. The results were as follows: the water content of the cooked rice continued to change rapidly for 10-20 min. Although the water content of the lower part decreased, the contents of the middle and upper parts increased, because the water moved upward. The hardness of cooked rice increased in the upper, middle and lower parts in order. The adhesiveness of the lower part indicated the lowest value. That of Koshihikari showed the higher value than Reimei. The hardness and adhesiveness of the cooked rice had relation with its water content. Sensory tests suggested that the rice was the most desirable which had been cooked for 20-30 min, and that Koshihikari was proffered to Reimei. Experiments with models which mixed paste-like substances (soluble starch solution, dextrin solution and Oneba respectively) with glass beads were made. The size of the glass beads was the same as that of the rice grain. The higher the concentration of past-like substances was, the more the hardness and adhesiveness of the cooked rice increased. Adhesiveness was recognized only in both the soluble starch and Oneba of Koshihikari. The Oneba consisted of more than 90% of carbohydrate and 4% of protein as anhydrous materials. The adhesiveness of Oneba played an important role in the texture of cooked rice as a mass., 4. Apparent Activation Energies and Fractional Free Volume of Retrograded Dangos (Part 1) Effects of Particle Sizes of Glutinous Rice Powders on Dangos Stored at Low Temperature (0℃) The creep behaviour for “Dangos”, which were prepared with various particle sizes of glutinous rice powder and were stored at O℃ for 1 h and 24 h, were measured in the temperature range of 10℃ through 55℃. The temperature dependences of shift factor, a_T, when the master curves at 25℃ were drown up, showed that the viscoelastic behavior of “Dango” was the WLF(Williams –Landel -Ferry) type. The apparent activation energy, △Ha, of “Dango” prepared with 150-200 mesh rice powder was maximum and the fractional free volume, f_0 of that was minimum. The value of △Ha for “Dangos” stored for 24 h were larger and the values of f_0, of that was minimum. The values of △Ha for “Dangos”, stored for 24 h were lagere and the values off_0 were smooth than those for 1 h. From these results, it was suggested that “Dango” prepared with 150-200 mesh powder possessed the finest packed structure, and the structure became tougher by storage for longer time. 5. Apparent Activation Energies and Fractional Free Volumes of Retrograded Dangos (Part 2) Effects of Particle Sizes of Non-Glutinous Rice Powder Stored at 0℃ and 25℃ and Comparison of Rice Powder Species (Glutinous and Non-Glutinous) The creep behaviors for “Dangos”, which were prepared with various particles sizes of non-glutinous rice powder and were stored at 0 and 25℃ for 1 and 24 h, were measured in the temperature range of 10 to 55℃. The apparent activation energies, △Ha, and fractional free volumes, for f_0, were calculated, then these parameters were compared with those obtained from glutinous one. The values of △Ha for “Dangos” prepared with non-glutinous rice powders were smaller and the values of f_0 were larger than those with glutinous rice powders with any particle size. “Dango” prepared with 150-200 mesh of non-glutinious rice powder possessed the maximal △Ha and minimal f_0, it was independent of storage temperature (0℃, 25℃) and storage time (1h, 24h), as same as glutinous one stored at O℃. These results suggested that “Dango” prepared with coarse powder possessed the porous structure resulted in the presence of clump of particulated aggregates. While, “Dango” prepared with 150-200 mesh powder had a fine packed structure. The structure of “Dango” prepared with glutinous rice powders was finer than that with non-glutinous one., 6. The effects of preparation conditions on the physical properties and microstructure of gomatofu The effects of the mixing rates (60, 150, 250, 350rpm) and the cooking times (15, 25, 35, 45 min.) on the physical properties of gomatofu (sesame tofu) were studied by using rheometer and scanning electron microscope (SEM). Gomatofu was prepared using two different kinds of cooking methods, the usual system A (simmering) and B (hot-water-dropping into cookpot to hold a constant quantity during cooking) were employed. The creep curve for the gomatofu could be analyzed by using a 4-element model. The hardness and elasticity of Hookean and Voigt body (E_0, E_1) of the (A) sample cooked for 25 min. decreased with mixing time for all of the samples of various mixing rates, and after cooking 25 min. increased with cooking time because of weight loss. Adhesiveness and the viscosity of the Newtonian and the Voigt bodies (η_N, η_I) of the sample mixed at 60 rpm increased with cooking time, while both of the samples mixed at 250 rpm and 350 rpm decreased with cooking time. Hardness, adhesiveness and gumminess of the (B) sample for all mixing rates decreased exponentially with an increase of cooking time, but cohesiveness did not change in all of the cooking times. Adhesiveness shored different changes among mixing rates. SEM observations revealed that the sample cooked with a mixing rate of 60 rpm for 15 min. did riot have a honeycomb structure, while the sample cooked with the mixing rate of 250 rpm for 25 min had uniform sized cells and a honeycomb structure. It was assumed that gomatofu is a phase separated model which has networks consisting of kuzu starch and sesame protein. 7. The effect of sesame contents on the viscoelasticity and Microstructure of gomatofu (sesame tofu). The changes in the viscoelasticities and microstructures of gomatofu (kuzu starch 40g, water 450g, sesame seed 0-80g ) prepared by simmering at a mixing rate 250 rpm for 25 minutes were investigated. This method of preparing gomatofu produced the most uniform size of air cells and honeycomb structure as described in our previous paper. Creep meter (RE-3305), scanning electron microscope (SEM, S-800) and syneresis observations were employed. The creep curve for the gomatofu was analyzed by using a 4-element modal, which consisted of Hookean and Voigt body elasticities (E_0, E_1) and Newtonian and Voigt body viscosities (η_N, η_I). The elasticities (E_0, E_1) of gomatofu increased and the viscosities (η_N, η_I) of that decreased an increase of sesame contents. SEM observations revealed that kuzu gel starch has a thick branched network microstructure, and gomatofu has a fibrous microstructure which surrounds globular sesame oil. It was found that 3% of syneresis ratio from kuzu gel starch occurred during the first 2 hours after preparation, while none occurred during the same time period for gomatofu (sesame contents 60, 80g). From these results, it can be seen that sesame components contribute to the strength and stability of kuzu gel starch., 学位の種類: 博士（農学）. 報告番号: 乙第1535号. 学位記番号: 新大博（農）乙第3号. 学位授与年月日: 平成8年9月17日, 新大博（農）乙第3号},
 title = {澱粉性食品の調理及び保存に伴う化学的物理的性状変化に関する研究},
 year = {1996}
}