Yeosu National Industrial Complex is one of Korea’s representative petrochemical industrial complexes where crude oil refining and petrochemical companies are concentrated. According to the results of the 2021 chemical emissions survey, during the process of manufacturing, storage, and transportation at the Yeosu National Industrial Complex, various hazardous chemicals, including hazardous air pollutants, volatile organic compounds and odorous substances are being emitted into the air, affecting the surrounding environment and the health of residents. The Ministry of Environment is applying strengthened standards by designating the Yeosu National Industrial Complex as an air conservation special measure area and establishing odor management areas to manage the air environment. Nevertheless, odor complaints continue to be registered and related complaints increase when turnaround work is carried out. Since air emissions are not counted during periods of turnaround as normal operations are temporarily suspended, it was difficult to establish policies to reduce odor complaints because the source of emissions and emission quantities cannot be ascertained with certainty. In this study, the extensive Yeosu National Industrial Complex was subdivided into 4 areas using a mobile vehicle equipped with PTR-ToF-MS capable of real-time analysis without sample pretreatment being carried out. Measurements were repeated during the day, night, and dawn while moving around the internal boundary of the plant and the boundary of each region where turnaround activities were being carried out. As a result, the recorded measurement for acrylonitrile was the highest at 6340.0 ppb and propyne and propene were measured the most frequently at 128 times each. Based on these results, it will be possible to help reduce emissions through process improvement by efficiently operating air measurement networks and odor surveys that conduct regular measurements throughout the year and providing actual measurement data to the plant. Also, it will help reduce odor complaints and establish systematic air management policies.
With changing dietary trends, active research is underway to substitute rice flour for wheat flour, commonly added to various processed foods. This study aimed to explore whether Baromi2, a floury rice incorporated in the production of Sujebi, can effectively replace wheat flour at appropriate levels based on its physicochemical and cooking characteristics. Baromi2 was categorized based on particle size (100, 140, and 200 mesh) and added in proportions of 10% and 20% relative to the weight of wheat flour. As the amount of Baromi2 increased, the protein and lipid content of the mixed flour also increased. Simultaneously, the dough strength decreased as the noodles became thinner, reducing hardness, gumminess, and chewiness. Additionally, a decrease in particle size increased peak viscosity and breakdown viscosity, whereas setback viscosity decreased. When Baromi2 was added at a 10% ratio, it displayed a low cooking loss, demonstrating desirable characteristics for Sujebi and was considered the most suitable proportion for production. These results provide foundational data for developing various rice-processed products using Baromi2, contributing to expanding consumption and enhancing utility.
This study evaluated the physicochemical characteristics of wheat-flour mixed powders and cooking properties of Sujebi based on the addition of ‘Baromi2’ rice flours for increased expansion of rice consumption. The addition rates at which a roll surface sheet was formed were selected as 0, 10, 20, 30, and 50% based on preliminary experiments with 0-90% addition rates of ‘Baromi2’. Results of physicochemical characterization showed that increasing the addition ratio of ‘Baromi2’ rice flour resulted in increased crude ash and crude fat levels, however crude protein and total starch decreased. The L*-value (lightness) increased with increasing addition ratio of ‘Baromi2’ rice flour; in contrast, a*-value (redness), b*-value (yellowness), and particle size decreased. Results of RVA showed that increasing the addition ratio of ‘Baromi2’ rice flour increased the peak, breakdown, and setback. Regarding textural properties, hardness and chewiness values were significantly reduced with increasing addition ratios of ‘Baromi2’ rice flour. Based on these results, a blending ratio of 20% or less of ‘Baromi2’ is considered suitable for producing Sujebi, and this result serves as basic data for the development of processed rice flour products using ‘Baromi2’.
This study investigated the quality characteristics and optimal conditions of noodles produced by adding Baromi 2 Garu floury rice to wheat flour. The lightness of samples with floury rice increased, while the lightness (L*), redness (a*), and yellowness (b*) decreased after cooking compared to before cooking. The weight, volume, and moisture absorption rate of cooked noodles decreased compared to wheat, but turbidity increased as the amount of rice flour increased. In addition, compared to the control with 20% rice flour, GR-20 (flour replacement by 20% Garu floury rice) with floury rice had lower turbidity, showing less cooking loss. The hardness, gumminess, and chewiness of noodles with floury rice decreased as the floury rice content increased, while springiness, cohesiveness, and adhesiveness increased. The elongation force and distance decreased as the amount of floury rice increased. Therefore, the optimal amount of floury rice to replace wheat flour would be 20%. Adding excessive amounts of floury rice to processed foods requires additional processes, such as adding food additives or changing the processing method to control physical properties.
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.
In existing ceramic mold manufacturing processes, inorganic binder systems (Si-Na, two-component system) are applied to ensure the effective firing strength of the ceramic mold and core. These inorganic binder systems makes it possible to manufacture a ceramic mold and core with high dimensional stability and effective strength. However, as in general sand casting processes, when molten metal is injected at room temperature, there is a limit to the production of thin or complex castings due to reduced fluidity caused by the rapid cooling of the molten metal. In addition, because sodium silicate generated through the vitrification reaction of the inorganic binder is converted into a liquid phase at a temperature of 1,000 °C. or higher, it is somewhat difficult to manufacture parts through high-temperature casting. Therefore, in this study, a high-strength ceramic mold and core test piece with effective strength at high temperature was produced by applying a Si-Na-Ti three-component inorganic binder. The starting particles were coated with binary and ternary inorganic binders and mixed with an organic binder to prepare a molded body, and then heat-treated at 1,000/1,350/1,500 °C to prepare a fired body. In the sample where the two-component inorganic binder was applied, the glass was liquefied at a temperature of 1,000 °C or higher, and the strength decreased. However, the firing strength of the ceramic mold sample containing the three-component inorganic binder was improved, and it was confirmed that it was possible to manufacture a ceramic mold and core via high temperature casting.
Consumer demand for imported and craft beer is increasing. Almost all the malt used by craft beer companies is imported. This study sought to develop a malting technology to expand the use of domestic barley, the main raw material for beer, and to examine its influence on the quality of domestic malt. The Hopum cultivar of beer barley was purchased and used at the Jeollanam-do Seed Management Center. A pilot-scale malting facility built by the National Institute of Crop Science was used. One sack (40 kg) of barley was sieved through screening sieves, and the barley was classified according to size (3.1, 2.8, 2.5, 2.2, and 2.2 mm), with the size-related composition being 18.1, 48.9, 23.3, 6.4, and 1.0%, respectively. The malt yields were 89.0, 87.6, 86.6, 82.2, and 76.1%, respectively. The coleoptiles elongation decreased as the barley size decreased. The protein content of malt tended to be high at small particle sizes of 2.2 mm. The soluble solid content of wort prepared from malt revealed good values of 17.4-17.5oBx, except for 15.3oBx for particles <2.2 mm in size. According to barley size in the malting process, these findings should be valuable quality indicators of malt.
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.