• KOREAN JOURNAL OF CROP SCIENCE
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• 제42권6호
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• pp.666-672
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• 1997

Twenty years' daily mean air temperature data was used to calculate the critical early seeding date(CESD), the optimum heading date(OHD), the critical late heading date for stable ripening(CHDR) and the critical late ripening date(CLRD) for rice seeded on dry paddy in different agroclimatic zones in Korea. The CESD was defined as the first day with mean air temperature of 13$^{\circ}C$, and the OHD as the first day of the 40 consecutive days with mean air temperature of 22$^{\circ}C$ or above after heading. The CHDR was defined as the date after which the cumulative daily mean air temperature would be at least 76$0^{\circ}C$. Lastly, the CLRD was defined as the last day when daily mean air temperature remains above 15$^{\circ}C$. This information was used for the estimation of periods from the earliest date of seeding to optimum heading date, the latest possible date of heading and the latest possible date of ripening in respective regions. For instance, in Suwon, those respective periods mentioned were found to be 104days, 124days, and 165days.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제12권
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• pp.43-48
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• 1972

The present experiments were carried out to find out the proper concentration of CEPA(2-chloroethy-lphosphonic acid) for the purpose of accelerating the leaf maturity and of reducing the nicotine content of tobacco. Varried levels of CEPA were sprayed Yellow Special A right after topping. The effects of each level CEPA treatment on leaf ripening and total alkaloid contents were periodically observed. The results are summarized as follows; 1. The higher the CEPA concentration was, the more the leaf maturity was accelerated. During the period from six to 11 days after treatment, the differences of leaf maturity among levels were prominent. 2. Treatment with CEPA only on the upper surface of the tobacco leaf, accelerated the maturity of that particular part treated, but not apparently the other parts of leaf. 3. The higher the CEPA concentration was, the more the accumulation of the total alkaloid was reduced. The reduction of alkaloid accumulation was evident after acceleration of leaf maturity. 4. Distinctive acceleration of leaf maturity was observed in the fully developed lower leaves, while reduction of alkaloid accumulation in the growing upper leaves. The degree of total alkaloid content reduced in the ripened leaves, however, were similer to all the leaves at different positions. 5. Yields of tobacco leaves were not significantly affected by CEPA treatment. 6. In the present experiments, it may be concluded that CEPA2, 000ppm is the most applicable level for accelerating leaf maturity and decreasing total alkaloid content. In the view point of the practical use, however, the applicable level is assumed to be properly choosed between 500 to 2, 000ppm, depending on the situations. 7. The mechanism of accelerating maturity and reducing alkaloid accumulation of tobacco leaves by CEPA, is further to be explored.

• Journal of the East Asian Society of Dietary Life
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• 제18권6호
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• pp.981-988
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• 2008

This study was conducted to develop functional black soy sauce with (S2) and without (S3) an outer skin and then compare these products to a control soy sauce (S1). In addition, the effects of different fermentation periods on the pH, buffering power, titratable acidity, total acidity, salt content, and browning and Lab value were evaluated. Furthermore, the antioxidative activities of the black soy sauce were compared to those of the control soy sauce based on the total phenolic compounds and free radical scavenging activity, including the 1,1-diphenyl-2-picryl-hydrazil (DPPH) scavenging activity and the thiobarbituric acid value (TBA value). The pH and buffering power of S2 were lower than of S1 and S3, while the titratable acidity and total acidity were higher. The salt content of all samples decreased after 60 days of fermentation, after which it increased slightly for up to 180 days. Additionally, the browning intensity of all samples increased as the fermentation periods increased, with the browning intensity at 420 nm of S1 being the highest followed by S3 and S2. After 150 days of fermentation, the L value of S1 was higher than that of S2 and S3, but the while a value of S2 was higher than those of S1 and S3 and was increased as the fermentation periods. Moreover, the b value of S1 was the highest at the end of the fermentation period, followed by the b values of S3 and S2. The amount of total phenolics in S1 was greatest, followed by S2 and S1. Conversely, the DPPH radical scavenging activity of S2 was the highest, followed by S3 and S1. Finally, the TBA value increased rapidly from day 30 to day 180 of the fermentation period, and the TBA value of S2 was lower than those of S1 and S3.

• Korean Journal of Food Science and Technology
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• 제11권3호
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• pp.162-165
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• 1979

In order to study the red-coloring effects of hot pepper fruit by light treatment during after-ripening period, 'Karak Geumjang No. 2 green hot pepper fruits, Capsicum annuum L., after 30 to 35 days from flowering were harvested and white, red and blue light treatments at the energy level of $40\;{\mu}watt/cm^2/sec$ were given at $25^{\circ}C$. When compared with white light, total chlorophyll content was strikingly decreased by blue light treatment and no difference in the chlorophyll contents between red and white light was observed. The chlorophyll a and b showed a similar decreasing patterns as shown in the case of total chlorophyll. Total carotenoid content was higher in the blue light treatment by 31% than the white light. However, red light decreased the carotenoid condent as compared to the white light treatment. But ${\beta}-carotene$ was not changed by red light as compared to white light. Blue light treatment increased ${\beta}-carotene$ content (0.71 mg%-f.w.) as compared to white light treatment (0.56 mg%-f.w.). Therefore, blue light treatment increased red-coloring responses of hot pepper fruit during after-ripening period. The capsaicin content was slightly increased by blue light and no red light influence was observed.

• Korean Journal of Weed Science
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• 제5권1호
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• pp.24-34
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• 1985

To estimate the fundamental situation of weed emergence and it's competition to paddy rice (critical competition period and threshold level) in the southern paddy area in Korea, two rice cultivars (Pungsanbyo and Tongjinbyo) under two cropping periods (Mono- and After-barley-cropping) were experimented. As a result, the dominant weed species (Monochoria vaginalis and Scirpus juncoides Roxb.) and the better emerging conditions (rather at the monocropping and cv. Punsanbyo) were identified. Also, the main components of yield decrease (25-55% of the weed-free check) of both cultivars as affected by weed competition were the number of spikelets, panicle and ripening rate in monocropping, and the ripening rate and grain weight in after-barley-cropping, respectively. Under the situation of combinated dominance with Monochoria v. and Scirpus j. among others, the duration of critical competition periods was enlarged.

• Journal of Microbiology and Biotechnology
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• 제3권4호
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• pp.266-269
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• 1993

The production of free non-volatile and volatile organic acids in Kimchi during fermentations at 30, 20 and $5^{\circ}C$, were determined by gas chromatography. The order in the amount of non-volatile organic acid, soon after preparation, was malic, citric, tartaric, pyroglutamic, oxalic, lactic, succinic and ${\alpha}-ketoglutaric$ acids. The major non-volatile acids at the optimum ripening time were malic, tartaric, citric and lactic acids, and as the temperature was lowered, the amount of lactic, succinic, oxalic, pyroglutamic and fumaric acids increased, while that of malic and tartaric acids decreased. The order in the amount of volatile acids at the beginning was acetic, butyric, propionic and formic acids. Among these acids, acetic acid was significantly increased in its amount during fermentation and the Kimchi fermented at low temperature produced more acetic acid than that fermented at high temperature.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• 제12권2호
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• pp.109-115
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• 2006

In response to the continuous changes in current consumer demands and market trends for postharvest produces, the functional application for agricultural packaging is becoming increasely significant. This paper focuses on the overview of important changes in physical and chemical status related to postharvest physiology and applications of the functional packaging materials for maintaining the freshness of fruits after harvest. During postharvest treatment and storage periods, fresh fruits undergoes the ripening process in quality attributes of the fruit such as major changes of texture, color, and flavor. Major fruit packaging technologies are concerned with correct gas permeable film and functions of ethylene removal, antimicrobial, and antifogging substances to keep the effective freshness. Application guidelines for the functional packaging in fresh produces were studied.

• The Korean Journal of Food And Nutrition
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• 제3권2호
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• pp.141-148
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• 1990

This studies were carried out to investigate the effects of non-volatile organic acids in the KimChi by lactic acid bacteria. The organism isolated from KimChi, Pediococcus dextrinicus, Leuconostoc mesenteroides, Lactobacillus plantarum and Lactobacillus brevis, were inoculated for preparation of KimChi. pH of all on the KimChi sample dropped sharply according as fermentation continued. pH of on optimum ripening period KimChi(4.4 and 4.2) reached 1.3 and 1.9 day at all on sample, respectively. Optimum acidity(0.5%) of KimChi were reached within 2 day all on sample. The total number of lactic acid bacteria reached 1.0X107cells/ml in 1 day and decreased slowly after 4 day. Main non-volatile organic acids were identified lactic, malic and succinic acid. The sensory score of mixed lactic acid bacteria inoculated KimChi was better than that of another KimChi.

• Proceedings of the Membrane Society of Korea Conference
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• 한국막학회 1995년도 춘계 총회 및 학술발표회
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• pp.1-4
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• 1995

The microstructure of polymer membranes produced via thermally induced phase separation (TIPS) of polymer solutions is a strong function of both the early-stage (by spinodal decomposition or nucleation & growth) and the late-stage phase separation (referred to in general as coarsening). In the case of early stage effects, the membrane morphology resulting from a nucleation & growth mechanism is either a poorly interconnecsed, stringy, beady structure which is mechanically fragile or a well interconnected structure with highly nonuniform pore sizes. In contrast, spinodal decomposition results in a well interconnected, mechanically strong membrane with highly uniform pore sizes. Here I describe recent quantitative studies of the coarsening effects on the microstructure of membranes produced via TIPS process. The dependence of microstructure on coarsening time, quench depth, solution viscosity, and polymer molecular weight was investigated in order to distinguish among three possible coarsening mechanisms, Ostwald ripening, coalescence, and hydrodynamic flow, which may be responsible for structural evolution after the early-stage phase Separation (spinodal decomposition or nucleation & growth).

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 한국미생물생명공학회 1976년도 제7회 학술발표회
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• pp.182.3-182
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• 1976

A laboratory study was made for developing an fermentative method of producing conventional Korean soy sauce type of product from sandfish and defatted soy bean Koji of Aspergillus oryzae as raw material and enzme source, respectively. As an attempt to shorten the fermentation period, the admixture, consisting of pre-chopped sandfish slurry and the Koji of Asp. oryzae (100：15, wet fish weight/dry Koji weight) with added water equal to the fish weight (v/w), was first allowed, while being agitated at 450rpm, to undergo digestion for a 5 hour period at $50^{\circ}C$ with no added salt and then then, after adding 20％ salt (w/v), the hydrolysate mixture was ripened for up to 13 weeks at $30^{\circ}C$ and $45^{\circ}C,$ At intervals, an aliquot was withdrawn for determining microbiological, chemical and organoleptic changes taking place in the sandfish-defatted soy bean koji mixture during both digestion and ripening period.