• Journal of Mushroom
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• v.17 no.4
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• pp.205-210
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• 2019

This study was conducted to elucidate the optimal nitrogen content for each variety of oyster mushroom (Pleurotus ostreatus) by investigating the change in the characteristics of fruiting body according to the nitrogen content of the sawdust media, and to use the results as the basic data for cultivation of high quality oyster mushroom. The nitrogen content was adjusted to 1.3%, 1.6%, 1.8% and 2.3%, and at each condition, mycelial growth was observed, which showed that the nitrogen content did not affect the rate of mycelial growth and density substantially. In the investigation of the characteristics of fruiting body, at the 1.8% nitrogen content, Chunchu No.2 showed the pileus diameter of 27 mm, and the stipe diameter and length of 11 mm and 61 mm, respectively, and the measurement of its color values revealed that the brightness of the pileus and the stipe was 31 and 80, respectively, offering the best commercial value, and yielding 25 valid stipes, which was the largest number. Likewise, at the 1.8% nitrogen content, Heuktari also showed the excellent growth characteristics including the pileus diameter of 29 mm and the stipe diameter and length of 10 mm and 68 mm, respectively, and the superb color values of the brightness of 37 at the pileus and 78 at the stipe. Moreover, the number of valid stipes was also found to be the highest with 19. In terms of morphological characteristics such as the pileus diameter and color, Soltari also produced the best mushrooms at the 1.8% nitrogen content and the number of valid stipes was high with 22. In summary, irrespective of varieties of oyster mushroom, high quality products could be cultivated at the nitrogen content of 1.8%.

• Korean Journal of Microbiology
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• v.52 no.3
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• pp.344-351
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• 2016

A marine bacterium, designated as strain 50C-3, was isolated from a seawater sample collected from the East Sea of South Korea. The strain is a Gram-negative, aerobic, yellow colored polar-flagellated bacterium that grows at $20-50^{\circ}C$ and pH 5.5-8.5. Optimal growth occurred at $40-50^{\circ}C$, at pH 6.5-7.5, and in the presence of 2% (w/v) NaCl. Based on 16S rRNA gene sequence similarity, the isolate was considered to represent a member of the genus Ruegeria. The result of this analysis showed that strain 50C-3 shared 99.4% and 96.98% sequence similarity with Ruegeria intermedia CC-GIMAT-$2^T$ and Ruegeria lacuscaerulensis ITI-$1157^T$, respectively. Furthermore, strain 50C-3 showed clear differences from related strains in terms of several characteristics such as motility, carbon utilization, enzyme production, etc. The DNA G+C content was 66.7 mol%. Chemotaxonomic analysis indicated ubiquinone-10 (Q-10) as the predominant respiratory quinone. Based on phenotypic, chemotaxonomic, and phylogenetic characteristics, the isolate represents a novel variant of the Ruegeria intermedia CC-GIMAT-$2^T$, for which we named Ruegeria sp. 50C-3 (KCTC23890=DSM25519). Strain 50C-3 did not produce cellulase and agarase, but produced alkaline phosphatase, ${\alpha}$-galactosidase, and ${\beta}$-galactosidase. The three enzymes showed stable activities even at $50^{\circ}C$ and thus regarded as thermostable enzymes. Especially, the ${\beta}$-galactosidase activity enhanced by 1.9 times at $50^{\circ}C$ than that at $37^{\circ}C$, which may be very useful for industrial application.

• Korean Journal of Food Science and Technology
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• v.46 no.6
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• pp.750-756
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• 2014

This study was performed to understand the effect of cultivation periods on the physicochemical characteristics of the starch of five sweetpotato cultivars, cultivated in Muan, Korea. Starch, protein, and ash contents increased with increased cultivation period, whereas amylose content decreased. Rapid viscosity analysis showed that the pasting temperature, peak viscosity, breakdown, setback and final viscosity increased with increased cultivation period. However, trough and final viscosity decreased. Although the onset temperature and peak temperature values increased, the conclusion temperature did not show any consistent patterns by differential scanning calorimetry. X-ray diffraction showed that the starch samples had C-type crystallinity irrespective of the cultivation period and cultivar. The starch granules were dominantly round and oval, or polygonal irrespective the cultivation period. The bigger the particle size was, the longer the cultivation period was.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.7
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• pp.833-840
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• 2017

For wide application of perilla leaf, which has various healthy functions and can be easily cultured across Korea, the physicochemical and sensory properties of pan bread made with various amounts of squeezed perilla leaf juice (SPLJ) were analyzed. When dough characteristics were analyzed by using farinograph, consistency and dough development time were not significantly different between the control and bread dough made with various amounts of SPLJ, whereas dough stability time increased with increasing SPLJ amount. Expansion rate of dough decreased with increasing SPLJ amount. The volume, specific volume, and baking loss rate of pan bread made with various SPLJ amounts decreased with increasing SPLJ amount. Pan bread crumb colors became thickened and greenish with increasing SPLJ amount. For physical properties of pan bread made with various SPLJ amounts, springiness and cohesiveness decreased with increasing SPLJ amount, whereas brittleness, chewiness, and hardness increased with increasing SPLJ amount. In the sensory strength analysis, pore uniformity and soft texture decreased with increasing SPLJ amount, whereas crumb color (dark greenish), perilla leaf odor, perilla leaf taste, and chewing texture increased with increasing SPLJ amount. In the overall acceptance analysis, 1.5% SPLJ was the most preferred with a score of 7.10. However, statistical differences between 1.5% and 1.0% SPLJ were not detected at P<0.05. In the partial least squares analysis, consumers liked bread with a green crumb color, perilla leaf odor, perilla leaf taste, and soft and chewing texture. In conclusion, physicochemical properties of pan bread made with SPLJ were less desirable than those of the control; however, consumer acceptance of pan bread made with 1.5% SPLJ was shown the highest. Therefore, methods for increasing physicochemical properties of pan bread made with SPLJ need to be developed for wide application of perilla leaf.

• Food Science and Preservation
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• v.22 no.3
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• pp.335-344
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• 2015

The objective of this study was to determine the rheological characteristics and sensory evaluation of yanggaeng by using the functional properties of Momordica charantia. Dried Momordica charantia was roasted at $180^{\circ}C$ to remove its bitter taste. The results of the study were as follows : The phenolic compound of Momordica charantia was $6.30{\pm}0.17mg/g$ in water extracts, which was the highest extractive rate. The anti-oxidant activity of non-roasted and roasted samples was determined in various phenolic concentrations at $50{\sim}200{\mu}g/mL$. The DPPH activities of non-roasted and roasted Momordica charantia water and ethanol extracts were 74.06~92.71% and 86.06~94.07%, respectively. The ABTS were 36.26~98.03% and 67.02~99.60% in water and ethanol extracts, respectively. The anti-oxidant protection factor of water and ethanol extracts were 2.19~2.25 PF and 2.20~2.36 PF respectively, and TBARS were 13.81~40.97% and 23.32~82.47%, respectively. The anti-oxidant activity of ethanol extracts was higher than that of water extracts at low phenolics concentration of $50{\mu}g/mL$, while the roasted sample was higher than the sample that was not roasted. The ${\alpha}$-glucosidase inhibition activity of non-roasted Momordica charantia ethanol extracts was higher than that of water extracts, showing that there were increasing pattern depending on the increases in the phenolics concentration of Momordica charantia. The texture, such as hardness, springiness, cohesiveness, chewiness and color changed in proportion to the concentration of Momordica charantia powder. Moreover sensory characteristics, such as color, flavor, taste, texture and overall acceptability of the non-roasted sample changed in proportion to the concentration of Momordica charantia powder. However, in the roasted sample, the sensory characteristics was improved at a lower concentration (below 1%). Thus, when the yanggang was prepared by Momordica charantia powder as a minor ingredient, it would be desirable to add it after roasting, in consideration of its functional and sensory properties, and at appropriate concentration on below 1%.

• Food Science and Preservation
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• v.18 no.5
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• pp.661-668
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• 2011

This study was conducted to devise appropriate blanching-process conditions as a means to convert Doraji, which is widely used in Korean food due to its unique fragrance and flavor, into frozen food materials for various uses. For the Hunter L values representing the brightness transformation among the surface color and gloss changes that were observed in Doraji before and after freezing, and after Doraji went through a blanching process, the specimen that went through a blanching process at $80^{\circ}C$ showed a significantly higher value compared to another specimen processed at a higher temperature, and the first specimen's value also rose after freezing. Meanwhile, for the hardness values, they declined more as the blanching temperature became higher and as the processing time became longer. For the number of total counts and the number of coliform groups, the number of total counts at $3.75{\times}10^5$ and $1.25{\times}10^5$ cfu/g before the blanching process was reduced into the approximately 2-3 log scale, and no coliform group was detected after the blanching process. As for the peroxidase activity, its activation was decreased by the blanching process, and more than 89% of the peroxidase became inactivated in all the specimens that went through the blanching process. The sensory characteristics of the frozen-thawed Doraji by test group showed the radish leaves blanched at $90^{\circ}C$ for 1 min to be the most highly evaluated in terms of the overall preference level (p<0.05).

• Food Science and Preservation
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• v.23 no.6
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• pp.778-787
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• 2016

Fermented vinegars using pear was compared according to the appled side materials. Quality characteristics of three kinds of the fermented vinegars (pear vinegar, PV; pear black rice vinegar, PBV; pear mint vinegar, PMV) were investigated, which includes pH, total acidity, colors, the contents of sugar, amino acids, total polyphenol, and total flavonoid, ${\alpha}^{\prime}{\alpha}-diphenyl-{\beta}-pycrylhydrazyl$ (DPPH) radical scavenging ability, and sensory evaluation. Brown rice vinegar (BRV) was used as a control. The pH and total acidity of the fermented pear vinegars were significantly different showing the range of 3.17~3.43 and 4.01~5.05%, respectively (p<0.05). The sugar contents of PV and PMV were significantly higher than other vinegars (p<0.05). L, a, and b values were the highest in PV, PBV, and PMV, respectively. Among the four vinegars, the essential amino acids were the highest in PV with the order of lysine, isoleucine, valine, and threonine. Besides, the fermented pear vinegars have many non-essential amino acids such as glutamic acid and aspartic acid. The aspartic acid content was the highest in PV while glutamic acid content was the highest in BRV. The total polyphenol content was the highest in PV while total flavonoid content was the highest in PBV. The DPPH radical scavenging ability (%) was the highest in PV. In sensory evaluation, PBV showed the highest color, taste and overall preference scores. These results show that pear would be desirable to prepare high-quality vinegars and functional foods.

• Korean journal of food and cookery science
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• v.26 no.4
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• pp.481-489
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• 2010

This study was conducted to identify the optimal mixing ratios of turmeric powder or beet powder for the production of jelly. To establish the amount of turmeric powder or beet powder that could be added to jelly, physicochemical sensory characteristics and textural properties were measured. Specifically, jellies were prepared using gelatin containing turmeric powder or beet powder at ratios of 0.5, 1, 1.5 and 2%(w/w). Sensory evaluation of color, appearance, sweetness, chewiness, springiness, hardness, transparency and overall acceptability of jelly prepared using 0.5% turmeric powder resulted in a high score. Similarly, the color, appearance, sweetness, chewiness, springiness, transparency and overall acceptability of jelly prepared using 1% beet powder received a high score. Taken together, the results of this study suggest that turmeric and beet can be useful in the production of high quality jelly.

• Korean journal of food and cookery science
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• v.27 no.5
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• pp.557-565
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• 2011

The objectives of this study were to investigate the physicochemical characteristics of soybean leaves in different cultivars and to develop a soybean curd prepared with soybean leave powder as a functional food. Four cultivars (Daewonkong leaf, Daepungkong leaf, Hwangguemkong leaf, and Seoritae leaf) were selected for this experiment. A significant difference was observed in the proximate composition of soybeans leaves (p<0.05). Soybean leaves had the highest content of carbohydrates. The mineral composition and isoflavone content in soybean leaves were significantly different among the cultivars (p<0.05). In particular, Daepongkong leaf had the highest content of genistein, daidzein, and total isoflavones. This study was also conducted to determine the quality characteristics of a soybean curd developed from daepongkong leaf with various concentrations (0, 0.1, 0.2, and 0.3%) of soybean leaf powder (SLP). The soybean curd yield rate increased according to the level of SLP added, whereas the L and a color values decreased. In the sensory evaluation, intensity scores for color, after taste, leafy taste, and chewiness were highest for the 0.3% soybean curd. The soybean curd with 0.2% SLP soybean milk attained the highest overall acceptability score. These results showed that soybean leaf was preferred over soybean curd containing 0.2% soybean leaf powder.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.363-370
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• 2018

The succulent plants of Echeveria genus are in increasing demand worldwide, but it is difficult to supply good quality young plants throughout the year because propagation efficiencies are depend on cultivar and environmental factors. This study was carried out to investigate the propagation efficiencies of leaf cutting in Echeveria cultivars at different LED light qualities in a closed-type plant factory system. Leaf cuttings cut from stock plants of six difficult-to-propagated cultivars 'Afterglow (AG)', 'Berkeley Light (BL)', 'Mason (MS)', 'Subsessilis Light (SL)', 'Cream Tea (CT)', and 'Ben Badis (BB)' were put into cutting media in the plant factory system maintained at a temperature of $24{\pm}2^{\circ}C$ and relative humidity of $60{\pm}10%$, and watered with over-head irrigation twice a week. Cuttings were irradiated with sole or mixed red (R, 660 nm), blue (B, 450 nm), green (G, 530 nm), and far-red (FR, 730 nm) LEDs as follows: R10, R8+B2, R5+B5, R7+B2+FR1, and R7+B2+G1. PPFD just above the cuttings was $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ and photoperiod was 16/8 (light/dark) hours. As a result, propagation efficiencies were dependent on cultivar. Rooting and shooting were relatively easy in 'SL' but shoot formation in 'AG' was very difficult. Light qualities from LEDs also affected plant regeneration. Light conditions with a higher ratio of B, R5+B5, R7+B2+FR1, and R7+B2+G1, promoted shoot formation and growth but inhibited rooting and root growth. R10 and R8+B2 with a higher ratio of R promoted rooting and root growth and inhibited shoot formation and growth of cuttings. In addition, the treatment with FR increased leaf size and biomass of the all plants. Therefore, further studies are needed to investigate the optimum compositions of LED light quality for the improvement of leaf cutting efficiency in difficultto-propagated Echeveria cultivars.