• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.10 no.3
• /
• pp.151-162
• /
• 1977

Distribution of marine algae is diverse in Korea and the resource of edible algae is abundant marking 239,037 tons of yearly production in 1976. They have been known as a protein source and used as a supplement in Korean diet. It is necessary to estimate the potentiality and properties of usable algal proteins especially as food resources and studies of extraction and separation of the proteins, therefore, are basically required for this purpose. In this study, the influence of various factors including the sample treatment, extraction time and temperature, sample us extraction solvent ratio and pH upon the extractability of the water soluble protein was determined. And the effect of precipitation treatment for isolation of the algal protein from the extracts was also tested. Nine species of algae, the major ones in consumption as food namely Porphyra suborbiculata, Undaria pinnatifida, Hizikia fusiforme, Sargassum fulvellu, Enteromorpha linza, Codium fragile, Sargassum kjellmanianum and Ulva pertusa were collected as fresh from Kijang, Yangsan Gun, in the vicinity of Busan city. The content of crude protein $(N\times6.25)$ of the algae ranged from $9.46\%\;to\;24.14\% showing the highest value in Porphyra suborbiculata and the minimum in Hizikia fusiforme. In the effort of maceration of blending methods on the extractability, immersion freezing in dry ice-methanol solution appeared most effective yielding 1.5 to 2.5 times extractability than that of the mortar grinding method. The effect of the ratio of sample vs solvent on extractability differed from species. It was enhanced at the ratio of 1:20 (w/v) in Ulva pertusa and Enteromorpha linza while the ratio was 1:30 (w/v) for Cedium fragile, Undaria pinnatifida, Hizikia fusiferme, Sargassum fulvellum and Porphyra suborbiculata and 1:40 for Sargassum kjellmanianum respectively. The effect of extraction time and temperature was revealed differently from species which might be caused by differences in the constitution of algal tissues resulting in that the extraction for 1 hour at $50^{\circ}C$ gave the maximum extractabilily in Ulva pertusa and Enteromorpha linza, 2 hours in Porphyra suborbiculata, Hikikia fusiforme, Undaria pinnatifida, Sargassum kjellmanianum and 3 hours in Codium fragile. And the extractability was higher at $50^{\circ}C$ to $60^{\circ}C$ for the most of the tested samples except Hizikia fusiforme. The optimum pH for the extraction was 9 to 12. The recovery of extractable nitrogen to the total nitrogen was $63\%$ in average with the first extracts and $8.6\%$ with the second extracts respectively. Both extracts were prepared by 2 hour extraction at $50{\pm}1^{\circ}C$ with dry ice-methanol frozen and seasand macerated materials. And these conditions assumed to be an optimum for the extraction of water soluble algal proteins since the nitrogen content after the first extraction covered $90\%$ of the total water extractable nitrogen. In the precipitation of the extracted proteins, Barnstein method and methanol treatment seemed to be more efficient than other precipitation methods.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.5
• /
• pp.707-714
• /
• 2005

Ingredient ratio for making nabak kimchi and the manufacturing method were standardized from the available literatures. Fermentation properties and $CO_2$ production of the nabak kimchi were investigated during the fermentation at $5^{\circ}C,\;10^{\circ}C,\;and\;20^{\circ}C$. Standardized ingredients ratio of nabak kimchi that added 100 mL of water was as follows: 45.0 g baechu cabbage, 26.9 g radish, 1.9 g green onion, 1.0 g red pepper, 1.2 g crushed garlic, 0.9 g crushed ginger, 0.7 g red pepper powder. The standardized manufacturing method of nabak kimchi was as follows: washing ingredients, cutting radish and baechu cabbage $(2.5\times2.5\times0.5\;cm)$, salting for 20 min, washing and draining, pretreatment of ingredients, dissolving red pepper powder in water, blending, mixing, and adding the water to the mixed ingredients. Fermentations at $5^{\circ}C$ for 8 days, at $10^{\circ}C$ for 3 days, and at $20^{\circ}C$ for 1 day led to the acidity levels of $0.21\%,\;0.20\%,\;and\;0.31\%$, respectively. From the relationships between optimally ripened pH and acidity, nabak kimchi showed lower acidity of $0.20\~0.25\%$ with pH $4.2\~4.5.$ Like other kinds of kimchi, the Levels of Leuconostoc sp. were high specially at later stage of fermentation at low temperature $(5^{\circ}C)$. However, the levels of Lactobacillus sp. were low at $5^{\circ}C$. Nabak kimchi produced high levels of $CO_2$ in the initial fermentation period and followed by rapid decrease of $CO_2$ production with the fermentation. From the relationships between pH and $CO_2$ content, the highest $CO_2$ contents were found pH $4.0\~4.4$, 3.8 and 3.4 at $5^{\circ}C,\;10^{\circ}C$, and $20^{\circ}C$, respectively. This fact indicated that fermentation at $5^{\circ}C$ has the highest $CO_2$ content at optimally ripened pH of 4.3 and the fermentation at lower temperature such as $5^{\circ}C$ could extend the eatable time of nabak kimchi.

• Journal of the East Asian Society of Dietary Life
• /
• v.18 no.4
• /
• pp.446-454
• /
• 2008

The traditional Korean drink "Jehotang", which is one of the most commonly prescribed drugs for treatment of the heat stroke accompanied by high fever, severe sweat and thirst, it is effective far quenching thirst strengthening the stomach, stopping diarrhea and regulating intestinal function. It is also known to play a role in activating the growth of useful microbes in the intestine and in multiplying intestinal immune cells. Thus, this study investigated all aspects of the drink in an effort to develop a new functional beverage. In the course of this study, the analytical research into the literature concerning Jehotang an error in the secrets of preparing the drink. The Japanese apricot, which was given the botanical name, "Prunusmume", should only be used with the flesh (scientifically referred to as "Fructusmume"), which is fumigated with straw fire before drying. and the seed should be thrown away. The honey should only be used after it is heated with a gentle fire, before removing the white foam that farms on its surface to make the "Yeonmil". Two kinds of cooking processes were found in the ancient literature. One procedure boiling down the powered Fructus mume mixed with the Yeonmil, while the other procedure involved preparing the Fructus mume's water by adding water to it and blending the water with the Yeonmil and the rest of the raw ingredient before boiling them down. The current procedure, in which the cooking is done in a double boiler, has been widely adopted to its simplicity. The finished Jehotang is put in porcelain, kept at room temperature, and consumed after mixing with cold water.

• Korean Journal of Environmental Agriculture
• /
• v.24 no.2
• /
• pp.191-197
• /
• 2005

Green house soils have been intensively cultivated with excessive application of compost and chemical fertilizer for vegetable growth. The objective of this study was to establish the reasonable fertilizer application system for rice cultivation in green house soil. Field experiment was carried out with rice cv. Geumo-byeo 1 in Jisan series soil (fine loamy, mixed, mesic family of Fluventic Haplaquepts) that was previously cropped with green pepper (Capsicum annuum L.) for the last 3 years. Treatment consisted of conventional fertilization $(N-P_2O_5-K_2O=11-4.5-5.7kg\;10a^{-1})$, no basal fertilization, 50% reduction of basal fertilization no top dressing, bulk blending fertilizer, and no fertilizer. The value of pH, available phosphate, and exchangeable potassium after experiment was lower than those before experiment while organic matter content was not difference in all treatment. The value of salt elusion was the highest in no basal fertilization plot. The amount of $NH_4-N$ in soil was higher in growth stage of rice as fertilizer amount increased in 1998. The changes of plant height and tiller were higher as fertilizer amount increased. Thousand-grain weight as yield component was higher in no basal fertilization plot all the year because of decreasing panicle. There was no significant difference in rice yield between treatments in 1998. However, conventional fertilization resulted in significantly increased rice yield in 1999. Nitrogen use efficiency was the highest in no basal fertilization plot in 1998 and in conventional fertilization plot in 1998. Our results suggest that no basal fertilization be best to increase salt elusion with slightly increased yield in first year for rice cropping after vegetable harvesting, which method improves fertilization efficiency. However, conventional fertilization was good for second rice cropping after vegetable harvesting in greenhouse.

• Analytical Science and Technology
• /
• v.23 no.5
• /
• pp.485-491
• /
• 2010

A certified reference material (CRM) of KRISS 109-03-SSD was developed for the analysis of hazardous elements in soil. The target elements were As, Cd, Cr, Cu, Hg, Ni, Pb, Zn being regulated by the Soil Environment Conservation Act. Starting material was collected from tailing dump of an unworked tungsten mine at Sangdong (Gangwon-do, Korea). The starting material under-went through a series of fabricating process steps of screening, drying, grinding, sieving, blending, bottling, sterilization and was certified according to the ISO Guide 35. Isotope dilution-inductively coupled mass spectrometry (ID-ICP/MS) and instrumental neutron activation analysis (INAA) were used for the measurement. Homogeneity was tested according to ISO 13528 annex B. The certified values were determined using the results from two different methods or from two independent measurements using a method. Finally, certified values of seven elements of arsenic, cadmium, chromium, copper, lead, nickel and zinc were determined. Mercury did not satisfied the criteria of homogeneity and the result would be provided for information only, together with iron and tungsten. It was also studied, the extractable fraction of elements by aqua regia according to the ISO 11466 protocol being frequently studied for the purpose of environmental monitoring. It was performed as a inter-laboratory study by 6 laboratories of a public institute and universities. Standard deviation among the laboratories was much bigger than the uncertainty of the certified value. The result of inter-laboratory study on the extractable fraction will be provided for information, only.