• Korean Journal of Food Science and Technology
• /
• v.21 no.6
• /
• pp.863-868
• /
• 1989

In comparison of contents of the components related to the quality of kiwifruit depended on the cultivars, the obtained results were as follows; Abbott showed the highest values in soluble solid, crude fat, firmness and specific gravity. Potassium, phosphorus, calcium and magnesium were estimated as the major minerals in kiwifruit and Bruno contained the highest amounts of potassium and magnesium. Bruno also had high concentrations of ascorbic, maleic, citric and fumaric acid when compared with the other cultivars. The changes in chemical components of kiwifruit (Hayward) by ripening stage were as follows; During ripening, the glucose and fructose contents were increased with decrease of sucrose content. Ascorbic, maleic, fumaric and succinic acid contents were considerably increased during ripening From the investigation of changes in protein pattern by electrophoresis! the new bands with about 17,000-23,50kd were shown during ripening.

• Food Science and Biotechnology
• /
• v.18 no.6
• /
• pp.1398-1403
• /
• 2009

Present study deals with variations of physicochemicals including $\gamma$-aminobutyric acid (GABA), $\gamma$-oryzanol, free sugar, lipoxygenase activity, fat acidity, and germination rate from Korean brown rice cultivars. With increase of storage time and temperature, GABA, $\gamma$-oryzanol, lipoxygenase activity, and fat acidity increased, whereas free sugar and germination rate was reduced. Among cultivars, 'Gopumbyeo' exhibited the highest contents in GABA and $\gamma$-oryzanol during 12 weeks storage at $25^{\circ}C$ (GABA: $28.6{\pm}5.6{\rightarrow}170.4{\pm}4.6\;mg/100\;g$, $\gamma$-oryzanol: $6.1{\pm}0.7{\rightarrow}6.7{\pm}0.4\;mg/g$) and 'Ilpumbyeo' significantly decreased in free sugar during 12 weeks storage at $10^{\circ}C$ ($1,423.7{\rightarrow}1,058.4\;mg/100\;g$). Moreover, 'Taebongbyeo' exhibited the highest quality owing to low lipoxygenase activity, low fat acidity, and high germination rate. In free sugar compositions, sucrose exhibited the highest content (>70%), followed by fructose (>7%), raffinose (>5%), glucose (>3%), and maltose (>2%) during storage. Based on our results, changes of physicochemicals in stored brown rice may be important information in processing food and functional properties.

• Journal of Ginseng Research
• /
• v.40 no.4
• /
• pp.409-414
• /
• 2016

Background: The low survival rate of in vitro regenerated Panax ginseng plantlets after transfer to soil is the main obstacle for their successful micropropagation and molecular breeding. In most cases, young plantlets converted from somatic embryos are transferred to soil. Methods: In vitro thickened taproots, which were produced after prolonged culture of ginseng plantlets, were transferred to soil. Results: Taproot thickening of plantlets occurred near hypocotyl and primary roots. Elevated concentration of sucrose in the medium stimulated the root thickening of plantlets. Senescence of shoots occurred following the prolonged culture of plantlets. Once the leaves of plantlets senesced, the buds on taproots developed a dormant tendency. Gibberellic acid treatment was required for dormancy breaking of the buds. Analysis of endogenous abscisic acid revealed that the content of abscisic acid in taproots with senescent shoots was comparatively higher than that of taproots with green shoots. Thickened taproots were transferred to soil, followed by exposure to gibberellic acid or a cold temperature of $2^{\circ}C$ for 4 mo. Cold treatment of roots at $2^{\circ}C$ for 4 mo resulted in bud sprouting in 84% of roots. Spraying of 100 mg/L gibberellic acid also induced the bud sprouting in 81% roots. Conclusion: Soil transfer of dormant taproots of P. ginseng has advantages since they do not require an acclimatization procedure, humidity control of plants, and photoautotrophic growth, and a high soil survival rate was attained.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.13 no.1
• /
• pp.117-126
• /
• 1984

Aflatoxins are toxic and carcinogenic secondary metabolites which are produced by trains of A. flavus and A. parasiticus during their growth on foods and feedstuffs. Aflatoxins are a group of closely related heterocyclic compounds of which $B_1$, $B_2$, and $G_2$ are the major members. Aflatoxins are synthesized via a polyketide pathway in which the general steps are acetate, an-thraquinones, xanthone and aflatoxins. Aflatoxin formation is favored by high moisture or high $a_w$(0.95${\sim}$0.99). The limiting $a_w$ for aflatoxin production on agricultural commodities is 0.83. Optimum temperature for aflatoxin production by the molds is $25{\sim}30^{\circ}C$ and the incubation time for the maximum production of the toxin is 7${\sim}$15 days. The limiting temperatures for aflatoxin production are ${\leq}7.5^{\circ}C\;and\;\geq40^{\circ}C$. Cycling temperatures may or may not stimulate aflatoxin production depending on the amplitude of cycling, substrate and strains of molds. Aflatoxin pro-ducing molds are aerobic organisms and thus have a requirement for oxygen. A decreasing $O_2$ concentration and/or increasing concentrations of $CO_2$ or $N_2$ depress the mold growth and aflatoxin formation. A. flavus grows competitively or associatively in the presence of other microorganisms and occasionally loses the competition with other microorganisms. Some lactic acid bacteria have been shown to reduce growth and aflatoxin production by A. parasiticus. Carbon source is the most important nutritional factors affecting aflatoxin formation by the molds. Sucrose, fructose and glucose are the most favorable carbon sources. Food substrates of plant derived products which have high carbohydrate content such as agricultural commodities and their products are most vulnerable to contamination by aflatoxins.

• Journal of the East Asian Society of Dietary Life
• /
• v.22 no.6
• /
• pp.886-894
• /
• 2012

For the development of Moru wine with enhanced sensory qualities, Moru (Vitis amurensis) wines were fermented with pine needles from Pinus densiflora Siebold et Zuccarini to make Moru-pine wine or medicinal herbs from Astragali Radix and Viscum album to make Moru-herb wine. Moru without pine needles or medicinal herbs was included as a control. Pine needles and Astragali Radix/Viscum album delayed the fermentation of Moru wine, but after 40 days of fermentation and aging, final ethanol contents, pH, acidity, and the sugar/organic acid content in these kinds of Moru wines had no differences. The final ethanol level and acidity of Moru wines were 11.5~12.9% and 1.1~1.2%, respectively, but any sugars (glucose, fructose and sucrose) were not detected in all Moru wines. These results are consistent with the general characteristics of Moru wines, which have a high acidity and low sugar contents. Relatively low browness and antocyanins were detected in Moru-herb wine decreasing its chromaticity in a sensory test. Overall, the supplements of Astragali Radix/Viscum album reduced the color of normal Moru wine, which might be applied toward the development of conventional Moru wines.

• Journal of the East Asian Society of Dietary Life
• /
• v.25 no.2
• /
• pp.326-332
• /
• 2015

Makjang is a kind of Korean traditional short-term fermented soybean paste. The purpose of this study was to evaluate the compositions of free sugars, organic acids and free amino acids as well as microbial counts of six kinds of Makjang. Commercial Makjang from different regions (Kangwon-do, Choongchung-do and Kyungsang-do) were used. The major free sugars of samples were glucose (0.15~3.97%) and maltose (0.01~0.54%), whereas sucrose (0.02%) was detected only in M4 and fructose only in M1 and M2. The major organic acids were citric acid (0.16~3.09%), malic acid (0.06~0.23%) and succinic acid (0.01~0.11%). The total content of free amino acids ranged from 0.02 to 8.74 mg/g, and major amino acids were detected in the order of glutamic acid, leucine, alanine and aspartic acid. Numbers of viable cells of bacteria as well as yeast and molds were $7.8{\times}10^4{\sim}4.8{\times}10^5$ and $8.1{\times}10^3{\sim}3.6{\times}10^4$, respectively. The results of the sensory evaluation showed that over-all preference of Kyungsang-do Makjang was higher than others. Consequently these results provide better information for standardizing and improving quality and functional activity of commercial Makjang.

• The Korean Journal of Community Living Science
• /
• v.28 no.4
• /
• pp.515-524
• /
• 2017

This research investigated the physicochemical properties and antioxidant activities of hot air-dried red mustard (Brassica juncea L.) leaf (HR) and freeze-dried red mustard leaf (FR). Crude protein content was highest in FR, and crude fat and carbohydrate contents were highest in HR. However, moisture and crude ash contents were not significantly different between the two drying methods. Total free sugars were higher in HR compared with FR. Sucrose, fructose, and glucose were the major free sugars in both HR and FR. Contents of essential and non-essential amino acids were higher in HR compared with FR. The major organic acid of FR was malic acid, and the major organic acid of HR was malic acid. The contents of saturated and unsaturated fatty acids were higher in HR than in FR. Total mineral contents were higher in FR (10,187.22 mg%) compared with HR (9,815.80 mg%). Major minerals were K, Ca, and Na in the two drying methods. The contents of vitamins C and E in HR were higher than those in FR. Total polyphenol contents showed no significant difference between the two methods. However, total flavonoid contents in HR were higher than in FR. The $IC_{50}$ values of FR and HR in ABTS assay were 0.89 mg/mL and 0.65 mg/mL, respectively. The results of all experiments suggest that HR and FR can be natural candidates as a rich source of antioxidants for further chemical investigation.

• Food Science and Preservation
• /
• v.10 no.4
• /
• pp.488-492
• /
• 2003

This study was analyzed to the components of leaf teas produced by manufature methods for which estimated food and nutritional values of Lindera obtusiloba loaves growed in Korea and had unique taste and aroma. There were identified to four kinds of free sugars in Lindera obtusiloba leaf teas and its content was the highest in the roasted tea among others. The contents of glutamic acid, aspartic acid, asparagine, and glycine were remarkably higher than other amino acids. The contentsof free amino acid in the leased tea and the androasted tea after steaming wase. 6 mg/100g had 101.5 mg/100g, respectively,had especially higher than in the others. Among the amino acid derivativer, phosphoserine, ${\alpha}$-aminobutyric acid, ${\beta}$-aminobutvic acid, and anserine contents were especially higher than others, but were not significantly difference by the manufacturing process. The volatile organic acids were composed acetic, propionic and butyric acid, and the nenvolatility organic acid were composed citric, oxalic, levulinic glutaric, lactic and pyroglutamic acid.

• Journal of the Korean Professional Engineers Association
• /
• v.28 no.5
• /
• pp.12-19
• /
• 1995

Korean fresh elephant -foot (Amorphophalus Konjak K. Koch) and its powder were analyzed and compared with foreign samples for the purpose of investigating the physico -chemical characteristics of Korean konjak. The Korean fresh konjak contains 80.64% of moisture and most of the solid component comprises sugar, protein and trace of fat and fibre. The mannan content of Korean konjak powder is far smaller than those of Japanese and Chinese konjak powder. The analysis of the korean konjak protein tells that 45% of glutamic acid, aspartic acid and argi-nine is included other remaining amino acid is larger with the order of valine, serine, leucine, and gly-cine. The Korean konjak contains a moderate amount of K component and other inorganic component increases with the order of P Na and Ca. The yield of konjak refined powder from dried chip was 61% and 51.5% of korean and chinese re-spectively. The whiteness degree of chinese konjak powder was slightly higher than that of korean product but the difference could not be recognized by the naked eye.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.12
• /
• pp.1621-1628
• /
• 2012

The agar-degrading bacterium GNUM-1 was isolated from the brown algal species Sargassum serratifolium, which was obtained from the West Sea of Korea, by using the selective artificial seawater agar plate. The cells were Gram-negative, $0.5-0.6{\mu}m$ wide and $2.0-2.5{\mu}m$ long curved rods with a single polar flagellum, forming nonpigmented, circular, smooth colonies. Cells grew at $20^{\circ}C-37^{\circ}C$, between pH 5.0 and 9.0, and at 1-10% (w/v) NaCl. The DNA G+C content of the GNUM-1 strain was 45.5 mol%. The 16S rRNA sequence of the GNUM-1 was very similar to those of Alteromonas stellipolaris LMG 21861 (99.86% sequence homology) and Alteromonas addita $R10SW13^T$(99.64% sequence homology), which led us to assign it to the genus Alteromonas. It showed positive activities for agarase, amylase, gelatinase, alkaline phosphatase, esterase (C8), lipase (C14), leucine arylamidase, valine arylamidase, ${\alpha}$-chymotrypsin, acid phosphatase, naphthol-AS-BI-phosphohydrolase, ${\alpha}$-galactosidase, ${\beta}$-galactosidase, ${\beta}$-glucosidase, catalase, and urease. It can utilize citrate, malic acid, and trisodium citrate. The major fatty acids were summed feature 3 (21.5%, comprising $C_{16:1}{\omega}7c/iso-C_{15:0}$ 2-OH) and C16:0 (15.04%). On the basis of the variations in many biochemical characteristics, GNUM-1 was considered as unique and thus was named Alteromonas sp. GNUM-1. It produced the highest agarase activity in modified ASW medium containing 0.4% sucrose, but lower activity in rich media despite superior growth, implying that agarase production is tightly regulated and repressed in a rich nutrient condition. The 30 kDa protein with agarase activity was identified by zymography, and this report serves as the very first account of such a protein in the genus Alteromonas.