• KSBB Journal
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• v.18 no.2
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• pp.117-121
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• 2003

The study was carried out to determine the effect of storage property and qualities on soybean sauce and paste by adding different amount of pyroligneous liquor obtained by sujpercritical fluid extraction(SFE). Purified pyroligneous liquor obtained by SFE at 4$0^{\circ}C$/110 bar contained p-cresol, o-cresol and m-cresol food sterilizers, but no toxic substances such as tar, scorched, furfuraland and monophenol. Thus pyroligneous liquor was considered to be suitable as natural food preservative. In case of soybean sauce, pyroligneous liquor was tested to determine the potential of natual food preservative to prevent flim formation on soybean ksauce 15days at 3$0^{\circ}C$. Increasing amounts of purified pyroligneous liquor added to soybean sauce prevented film forming yeasts. In case of paste, pyroligneous liquor was tested to determine the potential of natural food preservative to inhibit browning on paste 60 days at 3$0^{\circ}C$. Purified pyroligneous liquor added to paste inhibited brown pigment. As a result, purified pyroligneous liquor offered a promising way of improving the quality and storage property of soybean sauce and paste.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.10 no.1
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• pp.11-15
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• 1977

Brownish discoloration develops very rapidly in the storage of dried oyster. This undesirable browning is mainly caused by the series of reactions of sugar-amino condensation, enzymatic oxidation of tyrosine and/or the oxidative rancidity of lipids in the tissue of oyster. Sulfites are commonly used as inhibitors for Maillard type browning reactions in agricultural products. The inhibitory effect of sulfite treatment on canned oysters was also confirmed in some investigations. The results suggested that sulfites not only work on blocking tile amadori rearrangement but also on the reduction of free tyrosine which retards the progress of enzymatic oxidation of tyrosine tyrosinase. In this paper, the effect of sodium sulfite treatment on the reduction of reducing sugar and free tyrosine as a function i)f browning inhibition in oyster was tested and other treatment with glucose-oxidase and yeast were also applied. In preparation of samples, fresh oysters were soaked in sodium sulfite solution by various concentration for different treating times, washed in running water to remove the sulfite residue, and finally dried in the shade. In the result, the treatment of sodium sulfite was certainly effective on the reduction of both free tyrosine and reducing sugars in fresh oyster. The best results were obtained by the treatment of 0.5M sodium sulfite solution for 60 minutes each for soaking and washing. Treatment with, glucose-oxidase and yeast solutions, however, did appear somewhat effective but it required so much time for a certain effect that it seemed not practically applicable.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.22 no.2
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• pp.27-32
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• 2016

In this experiment, alcohol and blanching treatments were used for food packaging materials, quality of powder yam and sliced yams (5 mm size) were compared by alcohol concentration and time for measuring change of color, weight, moisture content saccharinity and decomposition. 5% and 10% alcohol were used to alcohol treatment for 5, 10 seconds each. Packaging materials were used OPP($30{\mu}m$), PET($25{\mu}m$), ON($25{\mu}m$) and all materials heat sealable were coated. Quality of powder yam were not changed during storage at low temperature however were changed during storage at room temperature after 5 days. In conclusion, powder yam were needed packaging materials with high water barrier property from moisture, sliced yams were high quality when packaged by ON and stored at low temperature. Therefore, using packaging materials with low oxygen permeability were expected to reduced quality degradation about browning of powder yam and sliced yams.

• The Korean Journal of Food And Nutrition
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• v.31 no.5
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• pp.689-695
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• 2018

This study was carried out to select apple cultivars suited for the fresh cutting or minimal processing as investigating correlation between total phenol and ascorbic acid as browning factors and the enzymatic browning degree. In soluble solid-acid ratio, 'Gamhong' and 'Arisoo' were highest value of 71.69 and 71.52 compared with other cultivars. And the change of lightness (${\Delta}L$) and color (${\Delta}E$) in 'Gamhong' and 'Arisoo' showed lower than other cultivars while 'Arkansas black' was highest change of lightness and color as ${\Delta}L$ 8.27, ${\Delta}E$ 13.86 respectively. Total phenol and ascorbic acid contents in 'Arkansas black' were highest such as 334.3 mg GAE/100 g and 9.22 mg/100 g, respectively. And polyphenol oxidase (PPO) activity also was the highest such as 14.43unit in 'Arkansas black'. The correlation test showed browning of apple was significantly dependent on ${\Delta}L$, ${\Delta}E$, total phenol, ascorbic acid contents and PPO activity (p<0.01). On the contrary, no significant correlation had been determined between the browning and ascorbic acid oxidase (AAO) activity. Thus, it seemed that the browning of apple was not only due to oxidation of ascorbic acid but also total phenol. It was suggested that 'Gamhong' and 'Arisoo' were suitable for fresh cutting or minimal processing.

• Korean Journal of Food Science and Technology
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• v.38 no.5
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• pp.635-641
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• 2006

In an attempt to find ways of improving the quality and sanitary state of dried squid, this study compared artificial drying methods i.e. hot air drying and cold air drying with natural drying method. The drying rates of squid were in the order of hot air, cold air and natural drying. However, cold-air drying was slower than natural drying at $7^{\circ}C$. The drying rates increased with increasing drying temperature. When drying temperature was close to the dew point on a dehumidifier surface, which was the case with cold air drying at $7^{\circ}C$, the driving force for dehumidification was lower than under other drying conditions, which resulted in a lower drying rate. There were little color differences between the drying methods and temperature. Squid dried by cold air-drying had better mechanical texture and sensory qualities than with other drying methods. In addition, the cold air drying method maintained superior quality in terms of the contents of amino acids, taurine, EPA, DHA, other fatty acids and a low TBA value than the other drying methods.

• Korean Journal of Agricultural Science
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• v.10 no.2
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• pp.269-276
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• 1983

Out of 50 seed samples of Sesamum indicum L. tested, Alternaria sesami and Corynespora cassiicola were detected in 29 samples and 38 samples, respectively. Heavy infection of A. sesami and C. cassiicola caused seed rot and seedling blight on water agar as well as in pots. In case of light infection the seed germinated showing elongation of the radicle and hypocotyl, but soon light brown or dark brown lesions appeared at certain parts of the shoot and root where sporulation of the fungi was observed after prolonged incubation in moisture. Four seed disinfectants were compared for the control of seed-borne infection of A. sesami and C. cassiicola. Complete control of seed-borne infection of C. cassiicola was obtained by seed treatment with Benlate T and Homai and seed treatment with Busan 30 was found superior to control seed-borne infection of A. sesami.

• Research in Plant Disease
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• v.10 no.1
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• pp.13-16
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• 2004

A basal stem rot disease of potato (Solanum tubersum) grown on hydroponic system in greenhouse was found in Jeju-city, Jeju Province of Korea in January 2001. The symptoms occurred on basel stem and root, and than plants eventually were died. The casual fungus isolate from basal stem rot symptom and identified to be Pythium myriotylum on the basis of mycological characteristics; Main hyphae wide were 8.4 ${\mu}{\textrm}{m}$ in size. Oogonia were spherical, smooth, mostly terminal in shape and 26.4∼31.2 ${\mu}{\textrm}{m}$ in size. Antheridia were 9.6∼14,4${\times}$4.8-9.6 ${\mu}{\textrm}{m}$ in size. Oospores were spherical, smooth, aplerotic in shape and 21.6∼26.4 ${\mu}{\textrm}{m}$ in size. This is the first report on the basal stem rot of potato caused by P. myriotylum in Korea.

• The Korean Journal of Food And Nutrition
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• v.30 no.1
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• pp.139-147
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• 2017

The objective of this study was to develop anti-browning agents for commercial ready-to-eat pear products, which are preferred not only to maintain the flavor, color and texture of pears, but also to increase consumers' preference. The sliced 'Shin-go (Niitaka)' pears were immersed in 5% and 10% oxidized starch, 1% citric acid, and 5% and 10% oxidized starch with addition of 0.1% sucralose for 3 minutes, and then they were packaged in vacuum sealed bags at $1^{\circ}C$ for 9 days. In order to evaluate the quality of packaged sliced pears, the quality index was determined in terms of color, firmness, soluble solids, and sensory quality. With the passage of storage time, no specific variation in firmness and soluble solids was observed. However, the ${\Delta}E$ value of the sliced pears treated with 5% oxidized starch solution was significantly lower than that of the other pears. Also, the Hunter L and b values of the sliced pears treated with 5% oxidized starch solution remained nearly constant from the beginning of storage. This observation shows that 5% oxidized starch solution was effective in reducing surface browning of sliced pears. Moreover, sliced pears treated with oxidized starch solution with addition of 0.1% sucralose were given an overall liking score which was slightly higher than that given to the other pears because of the sweetness of sucralose. In conclusion, 5% oxidized starch solution with addition of 0.1% sucralose was effective in reducing browning of sliced pears and in improving the taste of sliced pears.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.4
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• pp.348-357
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• 1988

The present work was undertaken to investigated the purification and characterization of polyphenol oxidase (PPO ; EC 1.10.3.1) in sweet potato, particularly the number of PPO isozymes, and PPO properties such as pH optimum, heat stability, substrate specificity, kinetics, and inhibitor studies. The purification achieved was 23.1 fold from crude extract with a yield of 41.5%. Eight PPO isozymes and twelve PPO isozymes were detected by disc polyacrylamide gel electrophoresis and isoelectric focusing, respectively. The specific activity of each isozyme separated by isoelectric focusing was in the range of $6,000{\sim}46,700U/mg$. This enzyme was sweet below $65^{\circ}C$ and the pH optimum of PPO occurred at 6.0-6.5. The substrate specificity of sweet potato PPO showed the high affinity toward the odiphenolic compounds. Km and Vmax for catechol were found to be 6.7 mM and $20{\triangle}A/min$, me protein, respectively. Inhibitor studies indicated that dithiothreitol was the most potent among the inhibitors used in the present work.

• The Korean Journal of Mycology
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• v.19 no.4
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• pp.285-291
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• 1991

Sulfur dioxide discharged from the factories in Yeochun industrial complex severely damaged to the growth of oyster mushrooms. The continuous monitoring indicated that high concentration of sulfur dioxide was repeatedly detected in Kwang-Yang and Seung-Ju. The first injury symptoms on the mushroom fruit bodies were observed a day later when sulfur dioxide was detected over 300 ppb. Under the high concentration of sulfur dioxide exposure, the young fruit bodies showed blight and sudden death and the mature fruit bodies turned to blue-brown and frequently progressed to blight. The symptoms at Spring cropping were more severe than those at Autumn cropping. The severity was associated with the frequency of sulfur dioxide monitored. However, sulfur content in the mushroom fruit bodies and culture media did not show clear differences between the injured mushroom from Yeochun industrial complex areas and normal ones from no damaged areas.