• Applied Biological Chemistry
• /
• v.39 no.1
• /
• pp.1-8
• /
• 1996

A one-stage, continuous-flow bioreactor with both immobilized and suspended cells was used to investigate the roles of lipid supplements in ethanol production by Saccharomyces cerevisiae. The reactor performance and the level of alcohol dehydrogenase(ADH) activities of the suspended cells, grown under various conditions, were measured. When ergosterol and/or oleic acid were added with surfactants to the yeast culture grown under non-aerated conditions, remarkable increases in ethanol production and cell growth was achieved, but specific ADH activities were not affected. Especially, no difference of specific ADH activities of the suspended cells grown under aerated and non-aerated condition was observed. The addition of the surfactant as a supplement also resulted in significant increases in ethanol production, cell growth, and specific ADH activity. When ergosterol and oleic acid were added to the yeast culture exposed to higher ethanol concentration($>40\;g/{\ell}$) level, ethanol production, cell growth, and specific ADH activity were increased, but the addition of surfactant was as effective as at lower ethanol concentration level. The results indicated that lipid supplements were more effective at higher ethanol concentration level than at lower ethanol concentration level during ethanol production. ADH isozyme patterns of the yeast cultures grown under various conditions on starch gel electrophoresis showed only one major band, probably ADH I. The migrating distance of the major isozyme, however, varied slightly according to the culture conditions of the cells. No apparent correlation was found between specific ADH activity and amount of ethanol produced. Cell mass was more important factor for ethanol production than specific ADH activity of the cells.

• Korean journal of food and cookery science
• /
• v.28 no.6
• /
• pp.789-796
• /
• 2012

This study attempted to investigate the characteristics of Superjami, which had a high C3G (cyandin-3-glucoside) content by comparing it with common rice (Ilpum) and black rice (Heougjinju, Suwon 415) for their components and physio-chemical characteristics. There were no significant differences in the water content, however there were significant differences in crude protein and crude fat in the order of Ilpum < Superjami < Heougjinju. As for the morphological characteristics of grains, it had been learned that Superjami was heavier and longer than the common rice, moreover Superjami had bigger seeds. As for the hardness of grains, the longer the time of steeping, the more decreased their hardness was at large. In the case of color, they showed significant differences in all the L, a, and b values of grains and flours. As a result of the experiment of pigment elution after steeping of the rice flours at $20^{\circ}C$ and $40^{\circ}C$, the longer the time steeping, the more increased the pigment elution became. The values are bigger with Heougjinju and Superjami than with Ilpum. As for the elution pH after rice steeping, the longer the time of steeping, the lower pH all the assays tended to have. As a result of the analysis of the total polyphenol contents of Ilpum, Heougjinju, and Superjami, it had turned out that the total polyphenol contents of Heougjinju and Superjami are 1.2 times as high as Ilpum, a common rice, and that Superjami is significantly higher than Heougjinju. As a result of the experiment of DPPH radical scavenging ability, there are significant differences among the assays in the order of Superjami > Heougjinju > Ilpum. Futher, it has turned out that Superjami has a higher DPPH radical scavenging ability than Heougjinju. Consequently, it can be stated that Superjami has a strong anti-oxidative ability. Thus, we should more precisely grasp the cooking characteristics of Superjami, which is in the state of brown rice, via comparing it with a common brown rice, and also provide opportunities to apply Superjamii to more foods by studying its starch characteristics in addition to its grain and flour properties.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.56 no.1
• /
• pp.57-63
• /
• 2011

Changes in food preferences and dietary habits of Korean prone to decrease consumption of the traditional energy source, rice. The exceeding condition of rice production in Korea is now not only impacting on the profit structure of farmers but also threatening food security. Although there have been several efforts to increase rice consumption rate, by developing various processed foods using rice flour, grain hardness of rice has been the most significant limiting factor. In this study, we addressed the suitability of the Namil(SA)-flo1, a mutant rice line has floury endosperm, in terms of producing rice flour by using dry-milling method, which is lower cost and more eco-friendly than other available methods such as wet-milling. Rice flour of the Namil(SA)-flo1 exhibited superior physico-chemical characteristics to any other check varieties including the wild type, Namil, in terms of distribution of granule sizes and content of damaged starch.

• Korean Journal of Food Science and Technology
• /
• v.49 no.5
• /
• pp.502-506
• /
• 2017

To improve the storage and firmness of Tteokbokki tteok Korean-style rice cakes with spicy sauce, steaming of the rice dough, soaking of the rice cake in acidic solution, and heat sterilization were conducted sequentially. The untreated control could be stored for 1 month under cold conditions, but this was extended to 10 months at room temperature ($15-30^{\circ}C$) after immersion in lactic acid solution (pH 4.0) for 20 min and heating to $100^{\circ}C$ for 30 min. The mechanical strength, which was related to firmness, was significantly increased to $11.4kgm/s^2$ compared with the untreated rice cakes ($8.8kgm/s^2$, p<0.05) and the overall descriptions of the sensory evaluation, including texture, was significantly higher than the control (p<0.05). The average size of the pores in the treated rice cakes was smaller than that of the conventional sample and the texture was improved as a result of decreased starch elution from smaller pores.

• Korean journal of food and cookery science
• /
• v.23 no.5
• /
• pp.731-748
• /
• 2007

In this study, we investigated e kinds and names of side dishes along with their recipes and ingredients occuring in Korean cookbooks published before the 17th century. The side dishes were classified 79 kinds of Guk, 23 kinds of Jjim and Seon, 15 kinds of Gui, 3 kinds of Jeon, 7 kinds of Nureumi, 3 kinds of Bokkeum, 30 kinds of Chae, 11 kinds of Hoe, 7 kinds of Jwaban, 6 kinds of Mareunchan, 12 kinds of Pyeonyuk and 5 kinds of Jeonyak, Jokpyeon and Sundae. The earliest records were found on Guk, Jjim, Jwaban, Po and Pyeonyuk Gui, Namul and Hoe were recorded after the 1500's and Nureumi, Jeon, Jeonyak, Jokpyeon and Sundae were developed relatively late in the late 17th century. As to the kinds of side dishes, Guk was the most common. Guks cooked before the 17th century used different recipes and more types of ingredients than today, including some that are not used today. For Jjim, various seasonings were added to main ingredients such as poultry, meat, seafood and vegetable. Most of the records found for Jjim used chicken as the main ingredient. Gui was recorded as Jeok or Gui and there weren't many ingredients for Gui before the 17th century. Gui was usually seasoned with salt or soy bean sauce and broiled after applying oil. Vegetables were broiled after a applying flour-based sauce. The Jeon cooked at that time was different from the one that is cooked today in that cow organs or sparrows were soaked in oily soy bean sauce before being stewed. Nureumi, which was popular in the 17th century, but rarely made today, was a recipe consisting of adding a flour or starch-based sauce to stewed or broiled main ingredients. Chae was a side dish prepared with edible plants, tree sprouts or leaves. Chaes like Donga and Doraji were colored with Mandrami or Muroo. Hoe was a boiled Hoe and served after boiling seafood. Jwaban was cooked by applying oil to and then broiling sparrows, dudeok, and mushrooms that had been seasoned and dried. For dried Chans, beef or fish was thin-sliced, seasoned and dried or sea tangle was broiled with pine nuts juice. There are some recipes from the 17th century whose names are gone or the recipes or ingredients have changed. Thus we must to try to rebuild three recipes and develop recipes using our own foods of today.

• Korean journal of food and cookery science
• /
• v.29 no.2
• /
• pp.137-146
• /
• 2013

Premature-green wheat is typically obtained by early harvest when culms of wheat still appear green in color, and the wheat and its food products have been considered as wellbeing foods. The pasting properties of prematured whole green wheat powder (WGWP), were analyzed with a rapid viscosity analyzer (RVA), and compared with commercial flours. The RVA values of lower peak viscosity and time, holding strength, final viscosity, as well as breakdown and setback viscosity showed that the WGWP could retard a gelatination of starch and also delay retrogradation in bakery products. WGWP with different levels of 10, 20, 30 or 50% was added into flours for preparing bakery product (bread, muffin and cookie), and their quality properties were evaluated. The addition of WGWP lead to a reduction in loaf volume of bread and muffin, and bakery products containing different levels of WGWP showed the changed internal surface structure (e.g. pore size) observed with a scanning electron microscope when compared with the control (0% WGWP). The hardness, gumminess, chewiness of bread and muffins were increased, and cohesiveness was decreased as the WGWP content increased, but the hardness of cookies was decreased. The bakery products added WGWP showed darker and more greenish and yellowish color than control (p<0.05). The sensory evaluation showed that bakeries with WGWP were scored to have more greenish taste and green color (p<0.05), and muffins and cookies with WGWP were evaluated to have more nutty and less oily taste (p<0.05).

• Microbiology and Biotechnology Letters
• /
• v.42 no.3
• /
• pp.219-224
• /
• 2014

In order to develop a new anti-diabetic ${\alpha}$-glucosidase inhibitor, we compared the ${\alpha}$-glucosidase inhibitory activity of the cell-free extracts of 48 strains of yeasts isolated from Korean fermented foods, and found that Pichia burtonii Y257-7 exhibited the highest ${\alpha}$-glucosidase inhibitory activity of 55.6%. The ${\alpha}$-glucosidase inhibitor was maximally produced when Pichia burtonii Y257-7 was cultured in LB broth (initial pH of 6.0) at $28^{\circ}C$ for 24 h. The ${\alpha}$-glucosidase inhibitor, partially purified by Sephadex G-50 gel permeation chromatography and systematic solvents extraction, revealed potent hypoglycemic effects in normal rats and streptozotocin-induced diabetic rats after the oral administration of starch.

• Korean Journal of Food Science and Technology
• /
• v.29 no.2
• /
• pp.362-368
• /
• 1997

As a preliminary study for the development of cancer-preventing functional food using Korean mistletoe, the cytotoxic effects of Korean mistletoe on between non-tumorigenic A3l cell and tumorigenic MSV cell derived from mouse 3T3 fibroblast cell line were investigated. While the raw extract, of which $ID_{50}$, value was $3.94\;{\mu}g/mL$, showed strong cytotoxic effect, its heat-treated extract was not cytotoxic up to $30\;{\mu}g/mL$. On the other hand, the heat-treated extract with law concentration showed an accelerative effect on the proliferation of non-tumorigenic A3l cell and an inhibitory effect on that of tumorigenic MSV cell. In addition, the influences of the addition of carbohydrates, such as galactose, lactose, glucose, mannose, fructose, sucrose and starch, to mistletoe extract were studied. There were not any significant changes with raw extract plus carbohydrate treatment, but the accelerative and inhibitory effects of heat-treated extract on each A3l and MSV cell were increased further by the treatment with sugars such as lactose, galactose, glucose, fructose. In order to investigate the changes of cytotoxicity of fermented Korean mistletoe according to fermentation periods, the raw and heat-treated extract were inoculated with Lactobacillus plantarum. During 1, 3, 5 and 7 fermentation days, the fermented raw mistletoe extract showed gradual accelerative effect on A31 cell proliferation without any changes of cytotoxicity on MSV cell. In case of the fermented heat-treated extract, however, the accelerative effect of heat-treated extract on A31 cell proliferation in early stage was disappeared during the fermentation.

• Food Science and Preservation
• /
• v.22 no.3
• /
• pp.392-398
• /
• 2015

The physicochemical properties of spray-dried rice flour with Lactobacillus plantarum CGKW3 were investigated. Amylose and damaged starch contents of spray-dried rice flour (S10, S20, S30, and S50) with L. plantarum CGKW3 were 14.18~17.75% and 24.65~34.08%, respectively. The particle size of spray-dried rice flour was $82.28{\sim}131.17{\mu}m$. The rice flour with L. plantarum CGKW3 showed a good powder flowability. The water absorption and water solubility of spray-dried rice flour were 1.96~2.13 and 9.91~21.95%, respectively. Thermal properties measured by differential scanning calorimeter revealed that the enthalpy (${\Delta}H$) for starch gelatinization were highest in the rice flour (S50) with L. plantarum CGKW3. When compared, the viable cell number of spray-dried rice flour were found to be in the following order: S10 (5.78 log CFU/g) < S20 (6.38 log CFU/g) < S30 (6.69 log CFU/g) < S50 (7.11 log CFU/g). The survaival rate of L. plantarum CGKW3 was 60.02-73.85%, which reflected the improvement in the quality of rice flour with an increase in treatment concentration. Based on our results, spray-dried rice flour with L. plantarum CGKW3 could be used in various types of rice foods.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.67 no.1
• /
• pp.9-16
• /
• 2022

Rice is one of the most important staple foods in Wnju, Jeonbuk, South Korea. However, rice consumption has dramatically decreased as eating habits have diversified owing to rapid economic growth. Recently, floury endosperm rice varieties have been developed to invigorate the rice processing industry, because dry-milled rice flour is economically and environmentally suitable for massive rice flour distribution. The National Institute of Crop Science has developed 'AromaT', an early-maturing black rice with floury-endosperm, suitable for tea and dry milling. 'AromaT' was derived from a cross between 'Suweon542' as the floury endosperm source and 'Heugjinju' as the black and aromatic source. In this study, 'AromaT' and its parents, 'Suweon542' and 'Heugjinju', were analyzed for agronomic traits, anthocyanin content, and their major physicochemical properties by different planting date. The field experiment was conducted in Wanju, Jeollabuk-do Province, South Korea, in 2019. The transplanting dates were May 30 (ordinary season), June 25 (double-cropping season), and July 10 (late season). The yield performance of brown rice 'AromaT' was 330 kg/10 a in the double-cropping cultivation method and was the highest among the transplanting dates. The floury endosperm of 'AromaT' was derived from 'Suweon542' containing 'flo7', located on chromosome 5 and known to control floury endosperm. With the late planting date, the anthocyanin content of 'AromaT' was 570.5 mg/100 g, much higher than that of 'Heugjinju' (376.3 mg/100 mg). The brown rice of 'AromaT' also exhibited the pop-corn-flavoring 2-acetyl-1-pyrroline, exclusively detected in aroma rice varieties. The average particle sizes of 'AromaT' and 'Suweon542' were 67.12 ㎛ and 70.9 ㎛, respectively, lower than that of 'Heugjinju' (95.5 ㎛) with a black transparent endosperm. The average damaged starch content of 'AromaT' was 8.1%, lower than that of 'Heugjinju' (10.05%) and Suweon542 (9.5%). As a result, 'AromaT' with high anthocyanin content, fine particle size, and low damaged starch content is expected to provide a new rice material in various processing fields.