This study investigated the nutritional characteristics of before and after fermentation of domestic soybean (Glycine max L.) by Rhizopus oligosporus. The soybean storage proteins, β-conglycinin (11S globulin) and glycinin (7S globulin), were the most abundant in Seonyu (SY) and Danbaegkong (DBK), with concentrations of 253.4 mg/g and 193.0 mg/g, respectively. For 11S/7S related to sulfur-containing amino acid, DBK had a value of 0.95, making it the most excellent nutritionally among all the cultivars. The free amino acid content significantly increased from 0.04~10.45 mg/g before fermentation to 1.37~16.95 mg/g after fermentation, and the essential amino acid composition increased, confirming an improvement in protein quality after fermentation. Phytic acid, known as a nutritional inhibitor of soybeans, decreased from 1.66~2.13 g/100 g before fermentation to 0.90~1.58 g/100 g after fermentation, suggesting that mineral absorption inhibition was alleviated. In addition, the trypsin inhibitor content is suppressed by 76.20% to 81.25% after fermentation, which is expected to improve protein utilization in the body. This study confirmed some properties of fermented products by Rhizopus oligosporus using domestic soybeans, and these results are presented to serve as the basic data for establishing new uses of Korean soybean cultivars.

This study was conducted to compare the quality characteristics of commercial tofu products from the market in Korea. Seventeen types of commercial tofu samples were taken and their physicochemical properties, including soluble solid contents, salinity, pH, total acidity and moisture (total solid contents), were analyzed. The hardness of tofu was negatively correlated with the moisture contents of tofu (r=－0.667**). The commercial tofu showed pH 5.80~6.24, total acidity of 0.016~0.034%, soluble solids of 1.50~3.45 °Brix, salinity of 1.20~2.30%, and moisture content of 79.91~87.57%, respectively. All 17 tofu samples sold in the Korean market were prepared using crude MgCl2 and sea water as a coagulant. The quality characteristics vary depending on the constituent’s of soybeans, and the ratio and amount of coagulants of tofu used. The origin of soybean seeds affected the yellowness of tofu; tofu made from imported soybean showed a higher b value than domestic soybean. These results are expected to be useful for understanding trends in the domestic tofu industry.

In vitro digestibility and protein digestibility corrected amino acid scores (PDCAAS) were investigated to verify the availability of protein in various Rhizopus oligosporus fermented products of domestic soybean (Glycine max L.) cultivars. Danbaegkong (DBK), Daepung (DP), Daewonkong (DWK), Saedanbaek (SDB), Seonyu (SY), and Cheongja4ho (CJ4) were used as raw samples, which were fermented using commercially available Rhizopus oligosporus for 48 h. All cultivars showed increased crude protein content after fermentation. The crude protein content of DBK and SDB was significantly higher than that of the other samples (55.12% in DBK and 54.22% in SDB) (p<0.001). CJ4 had the highest alanine content of 28.88 mg/g (p<0.001), and no significant difference in cysteine content was detected among the cultivars. In most of the fermented samples, the in vitro digestibility was 0.9 or higher, indicating high protein in the fermented samples. However, it is considered that restrictions on digestion are low. In DWK, the amino acid content and PDCAAS, which together indicate protein quality, were 0.917 and 0.855, respectively, confirming that it was the best cultivar to provide the raw material for fermentation. In conclusion Rhizopus oligosporus fermented soybean products can be considered a prospective source of protein with high utility value.

The purpose of this study was to investigate the Maillard reaction–related physicochemical properties of three maize varieties (Kwangpyeongok, Sinhwangok2ho and Gangdaok) after roasting them for different times (0, 15, 25, 40, and 55 minutes). The Maillard reaction is a non-enzymatic browning reaction involving reducing sugars and amino compounds. The content of reducing sugar, the causative agent of the Maillard reaction, decreased as roasting time increased. Gangdaok showed the lowest reducing sugar content of 1.04 mg/g after 55 minutes of roasting. In the elapsed roasting time, chromaticity ‘L’ and ‘b’ values decreased. At 55 minutes of roasting, wherein the Maillard reaction occurred most actively, Gangdaok showed the lowest ‘L’ value of 56.37 and the highest ‘a’ value of 7.60. Gangdaok had superior conditions for inducing the Maillard reaction compared to other varieties, and it is consider that 'flint–type', an endosperm characteristic, may have been the influencing agent. This study detected a total of 52 types of volatile aroma compounds (VACs), of which 28 were produced after roasting. Of the total VACs detected, 2-Formyl-5-methylfuran and 2-Furancarboxaldehyde accounted for 43.8~45.5% and have been confirmed to be the major VACs present in roasted maize. Most of the correlations between the Maillard reaction–related characteristics showed high correlation coefficients.

The effect of 16 cultivars on the quality of the rice porridge was investigated. The ‘Geunnun’ had the highest water absorption rate, but the ‘Segyejinmi’ yield (w/w) was the highest. The total sugar content of the rice porridge was 0.29~8.10%, showing significant variation among the cultivars. High amylose ‘Dodamssal’ and ‘Hwaseonchalbyeo’ glutinous rice displayed rotational viscosities of <20,000 cP. Rotational viscosities for boiled rice cultivars were 30,000~40,000 cP, representing an intermediate level, and the rotational viscosities of ‘Geonyang2’ and ‘Hanareum4’ were over 50,000 cP. These results suggest that the viscosity of rice porridge varies significantly among raw material cultivars. Among other variables affecting the texture profile of rice porridge, there were significant differences in hardness and gumminess among the cultivars. As a raw material, ‘Baekokchal’, a kind of glutinous rice, is known to be whiter than the non-glutinous rice, but after processing to porridge, it showed the lowest L value (71.1). Starch degrading enzyme activity was not significant in most types of rice porridges within 30 or 60 minutes. Therefore, enzymatic starch degradation is thought to be completed within 30 minutes. Among the tested raw materials, ‘Miho’ was 73.5 μg/mg, indicating the best digestibility in vitro.

Saengcheonggukjang, known as Natto in Japan, is a soybean fermented food which is made from steamed soybean, Bacillus and water. Demand of Saengcheonggukjang has increased because it does not have much smell compared to Cheonggukjang. Seven varieties of Saengcheonggukjang were investigated and compared in terms of 100 seed weight, quality characteristics, hard seed rate, and water absorption rate in order to determine the suitability of Korean soybeans. In addition, each characteristic of Saengcheonggukjang was compared. ‘Hoseo’ and ‘Haewon’ showed low 100 seed weight with 8.41 g and 8.11 g, respectively. The water absorption rate was higher in ‘Hoseo’ and ‘Pungwon’ than in Japan varieties. The yield of Saengcheonggukjang was significantly different for each variety. No differences were observed in yield and hardness of Saengcheonggukjang with respect to the varieties and sowing date. ‘Haewon’ showed the highest amino nitrogen content with 575.0 mg%. Viscous material content did not appear to differ between varieties. These results suggested that ‘Hoseo’ and ‘Haewon’ can be considered as suitable candidates for yield and quality of Saengcheonggukjang compared to Japan varieties.

This study was carried out to investigate milling's effect on the pasting properties and storage stability of dry-milled rice flour. Rice flour's moisture content was increased from 9.48% to 9.80% after going through a rice polisher, and the crude fat content of rice flour was decreased from 0.91% to 0.62% after going through a rice polisher. In the color index of rice flour, the rice polisher was only affected by yellowness. The pasting properties were verified through RVA, and it was confirmed that the use of a rice polisher had no significant effect on the pasting properties. As a result of observing the changes in fatty acid value, it was ascertained that the storage period could be increased using the rice polisher. These results suggest that the rice polisher can increase the storage period without changing the pasting properties.

This study was conducted to compare the quality characteristics of firm tofu (coagulant calcium chloride, CaCl2 used) made from eight imported and four domestic soybeans selling in Korean markets. The 100-seed weight of soybeans imported from China and Seonpung cultivated in Korea was the highest at 33.23 g and 32.51 g, respectively. Soybeans imported from the USA (bulk type) showed the lowest at 16.12 g, followed by Ukraine at 16.94 g, and Brazil at 18.51 g. The range of protein and fat in the 12 soybeans was 37.08~41.36% and 18.35~22.17%, respectively. The isoflavone contents were the highest in Daepung2 cultivated in Korea at 3,764.10 μg/g and the lowest in soybeans imported from Brazil at 1,439.85 μg/g. Tofu yield among the samples was in the following order: Seonpung (235.2%), China (232.0%) Daepung2 (228.7%), Daechan (225.7%), and Brazil (208%). Tofu made with soybeans cultivated in Korea (including from China) showed a higher yield compared to that made from soybeans from seven other countries. In the analysis of the correlation of quality factors of tofu, the hardness of the tofu was correlated with 100-seed weight (r=0.676*) and protein content of the soybeans (r=0.837**). Tofu yield was correlated with 100-seed weight (r=0.748**) and protein content of the soybeans (r=0.583*).

This study was conducted to secure basic information for corn processing by comparing the quality characteristics according to maize cultivars and kernel types (dent, intermediate, flint-like). As a result of analyzing 15 cultivars, a range of measurements were observed: 100-kernel weight, 22.89~35.63 g; moisture, 7.57~8.42%; crude protein, 8.46~11.45%; crude lipids, 3.26~4.83%; Hunter’s L-value, 83.70~86.79; a-value, 2.61~5.49; b-value, 22.01~28.15; and total carotenoids, 6.74~17.07 μg/g. Significance among the cultivars was shown in all quality characteristics (p<0.001), but the significance among the kernel types was found only in crude protein (p<0.005), crude fat (p<0.001), and Hunter’s L-value (p<0.05). The hardness of maize was decreased proportionally to the soaking time for all maize cultivars (p<0.001). In particular, with the same soaking time for different kernel types, the hardness difference was shown in the order of flint-like > dent ≒ intermediate. It was confirmed that the decrease in the hardness of flint-like kernel of close to that of hard-type starch was slowed compare dent and intermediate kernels. So it is expected the some characteristic of kernel types will contribute to the appropriate customized use of the developed cultivars.

The purpose of this study was to compare the quality characteristics of silken tofu products from the commercial market in Korea. Seven types of commercial silken tofu were sampled and their physicochemical properties, including soluble solid contents, salinity, pH, total acidity, moisture contents (total solid contents), crude protein and fat contents were evaluated. The TPA results suggest that the texture of silken tofu was very different from one another according to the type of and the amount of coagulant. The commercial silken tofu showed a range of pH 5.53~6.48, total acidity of 0.12~0.32%, soluble solid contents of 2.62~5.07 °Brix, salinity of 2.28~4.30%, and moisture contents of 87.10~92.24%, respectively. In terms of the coagulant of tofu, besides the GDL (glucono-δ- lactone), other coagulants such as MgCl2 for making ‘silken tofu’ in the Korean tofu market. The quality characteristics differed depending on the constituents of sample and the coagulants of tofu used. These results are expected to be useful in identifying new trends in the domestic silken tofu industry.

The purpose of this study was to derive the conditions for manufacturing rice porridge with optimum properties after reheating. The characteristics of rice porridge according to the soaking time, water addition rate, heating temperature, heating time, and cooling conditions were compared using the ‘Samkwang’ cultivar. In Step Ⅰ, as the heating temperature increased, the weight change decreased and the viscosity increased, and the temperature known as the main factor of the gelatinization also appeared to affect the viscosity increase. In Step Ⅱ, the viscosity and the texture properties was not significantly different as the soaking time was reduced, and 10 minutes was suitable because of due to the shortening effect of the total process time. In Step Ⅲ, the residual heat was lowered by cooling after the rice porridge production, so the viscosity could be greatly reduced. Also, it was confirmed that the water addition rate of 900% and the heating temperature of 15 minutes were optimal manufacturing conditions. The next study will investigate the porridge processability of rice cultivars using these results.

When producing rice products, it is very important to select suitable raw materials. Therefore, in this study, the quality characteristics of 16 rice cultivars were quantified to determine the criteria for evaluating the machinability of raw rice. The L value, which can affect the color of porridge prepared from rice, was the greatest for Hwaseonchalbyeo (84.17). The water-binding capacity, related to water interaction, was high in Hyangcheola (113.2%), and water solubility was high in Shingil (22.3%). Dodamssal (42.3%, 70.7 RVU) and Hwaseonchalbyeo (4.7%, 27.8 RVU) showed lower final viscosity compared to the cultivars in which the amylose content was medium groups (16.4~21.2%, 173.6~277.2 RVU). Specifically, cultivars with high or low amylose content had a low viscosity. The characteristics of the distribution of raw rice quality data were confirmed through 11 histograms. Furthermore, amylose content vs. water solubility, water solubility vs. peak viscosity, and peak viscosity vs. final viscosity showed high correlations (r=0.542, －0.569, and 0.836 respectively, p<0.01), and clear cultivar discrimination by the standard error of the mean (0.765~10.811). In conclusion, amylose content, water solubility, and peak viscosity were considered the most suitable characteristics for the quality evaluation of raw rice.

In this study, the physicochemical traits of soybean (100-seed weight, seed coat rate, protein content, composition, and amino acid content) and the quality of tofu (texture and sensory characteristics) were evaluated in order to determine the features of six varieties (Saedanbaek, Daechan, Daepung2, Seonpung, Miso, Saegeum) in terms of textural and sensory characteristics of tofu. Regardless of cultivar, the order of amino acid composition rate was as follows: Glutamic acid > Aspartic acid > Arginine > Leucine > Lysine. Approximately 50-60% of tofu (dry weight) consisted of protein, and among the cultivars, Tofu made from Saedanbaek showed the highest amount of protein at 59%. It was followed by tofu made from Miso at 54%. The rest contained about 50% protein. According to the result of correlation, crude lipid (-0.933**), crude protein (0.961**), and total phosphorus (0.924**) were strongly correlated with tofu hardness, and such factors could be utilized as an indicator of tofu quality.

In this study, the product characteristics and physicochemical properties were investigated through collection of commercial porridge. The addition rate of grain raw materials was about 6.5~11.75%, glutinous rice was added at a rate of about 23~60% to improve the viscosity and various other food additives were used. The moisture content characteristics varied among the products. The rotational viscosity of CP (Commercial Porridge)4 was the highest at 39,054 cP, while the flow viscosity of CP3 was least at 4.80 cm/30 seconds. The starch content differed among the products in the range of total starch 6.96~8.08%, amylose 1.41~2.61%, total sugar 6.55~12.81% and reducing sugar 0.50~0.99%. Particularly, total sugar showed a very high correlation ( 0.920) while rotational viscosity and color value (b) showed significant correlation with most of the properties i.e. moisture, solids content etc. There was a rapid increase in the reactivity of starch degrading enzyme at the early stage of the reaction which gradually decreased with time. The physicochemical characteristics of commercial porridge presented in this study could be expected to increase the industrial use value of the related research because it considers the quality of the currently commercialized porridge for the future selection of suitable porridge raw materials.

Quality characteristics of commercially available soybean and mung-bean flours in Korea were evaluated relative to product information such as bean content, price, chromaticity, proximate composition, water binding capacity, swelling power and solubility. Origin of raw materials was 23 in domestic products and 19 in imported products. The price of the product was 3.48 times more for raw soybean flour, 3.34 times more for fried soybean flour, and 3.47 times more for mung bean flour compared to imported soybean. In the domestic products, the lightness of raw soybean flour was higher than roasted soybean flour. The redness and yellowness of roasted soybean flour were higher than raw soybean flour. Moisture content of raw soybean flour was higher than roasted soybean flour, and crude fat, crude protein and carbohydrate content were higher in imported soybean flour. Ash and crude protein contents of mung bean were slightly higher than imported products. Water binding capacity of roasted soybean flour in domestic products was higher than raw soy flour, and there was no significant difference in solubility and swelling power. Correlation between quality characteristics of commercially available soybean and mung-bean flours products was found to be highly significant among measured items, except for solubility.

Palatability and texture analysis of nine Korean rice cultivars were investigated to select the most appropriate rice variety for the cooked-rice processing. The rice cultivars studied consisted of Samkwang, Seonpum, Wolbaek, Andabyeo, Dasan-1, Ilpum, Haiami, Jungsanggold and Chindle. They revealed the moisture, protein, amylose and starch contents of 10~12, 5~6, 12~19, and approximately 90%, respectively. Among the evaluated rice varieties, WB exhibited the lowest amylose content (12.7%) and Jungsanggold the next (17.2%). In the rapid-visco analyzer test, Jungsanggold, Chindle, Wolbaek and Seonpum revealed a low value of final and setback viscosities than other varieties. Using a toyo meter analyzer, Chindle, Haiami, Samkwang were selected as having high toyo palatability values, while Dasan-1, Wolbaek and Andabyeo revealed low values. Toughness and adhesiveness of all nine cooked rice varieties were highest in Jungsanggold, Chindle and Ilpum. Also, palatability of cooked rice was highest in the following order: Chindle (80.03) > Samkwang (76.21) > Jungsanggold (74.08). The results of this study suggest that Chindle may be effectively used to produce processed cooked rice.

This study was carried out to analyze the pasting and antioxidant characteristics of cooked mixed grains consisting of germinated millet and rice with varying addition rates and cooking methods. In this study, we chose two foxtail millets: glutinous (‘Samdachal’) and non-glutinous (‘Samdame’), along with a glutinous proso millet (‘Ibaekchal’). Cooked mixed grain rice-added germinated millet was cooked by general and high pressure cooking methods, with and without fermented alcohol. The peak and trough viscosity of germinated millet were decreased significantly with increasing amounts of germinated millet. The phenolic compounds and radical scavenging activity of cooked rice-added germinated millet increased significantly with the addition of germinated millet (p<0.05). The total polyphenol contents of cooked rice-added germinated Samdachal, Samdame, and Ibaekchal were 127.74~194.11, 128.20~192.56, and 128.88~171.28 μg GAE/g, respectively. The total flavonoid contents were 13.79~30.23, 14.77~25.99, and 15.28~29.56 μg CE/g, respectively. DPPH and ABTS radical scavenging activities were 3.31~5.73 and 6.31~9.69 mg TE/100 g for cooked rice-added germinated Samdachal; 3.14~8.58 and 6.05~10.19 mg TE/100 g for Samdame; and 3.37~7.45 and 6.27~9.27 mg TE/100 g for Ibaekchal, respectively. In this study, phenolic compounds and radical scavenging activity of cooked mixed grain rice-added germinated millet with different addition rates and cooking methods can be used as basic data for manufacturing processed products.

This study aimed to evaluate the fermentation characteristics of mixed Makgeolli with barley and wheats under, fermentation at different temperatures (20, 25, and 30℃) and time (3, 6, and 9 days). The pH and sugar of mixed Makgeolli were 3.68~4.26 and 12.30~17.31 ∘Brix, respectively. The total acidity showed proportionate increase with fermentation temperature and time; whereas, reducing sugar contents decreased with increasing fermentation temperature and time. The alcohol contents of mixed Makgeolli varied significantly by fermentation temperature and time (p<0.05). In terms of color values, the L value decreased with increasing fermentation temperatures, and a value increased significantly with increasing fermentation time. The number of microorganisms (yeast, total bacteria and lactic acid bacteria) in mixed Makgeolli decreased progressively with increasing fermentation temperature and time. Among the organic acids (citric, lactic, malic, and pyruvic acids) in mixed Makgeolli, citric and lactic acid was present at the highest concentrations. From these results, the optimum fermentation conditions of mixed Makgeolli with barley and wheat were 20~25℃ for 6 days.