• Journal of Mushroom
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• v.18 no.1
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• pp.1-9
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• 2020

Mycorrhiza refers to the association between a plant and a fungus colonizing the cortical tissue of the plant's roots during periods of active plant growth. The benefits afforded by plants from mycorrhizal symbioses can be characterized either agronomically, based on increased growth and yield, or ecologically, based on improved fitness (i.e., reproductive ability). In either case, the benefit accrues primarily because mycorrhizal fungi form a critical linkage between plant roots and the soil. The soilborne or extramatrical hyphae take up nutrients from the soil solution and transport them to the root. This mycorrhizae-mediated mechanism increases the effective absorptive surface area of the plant. There are seven major types of mycorrhizae along with mycoheterotrophy: endomycorrhizae (arbuscular mycorrhizae, AM), ectomycorrhizae (EM), ectendomycorrhizae, monotropoid, arbutoid, orchid, and ericoid. Endomycorrhizal fungi form arbuscules or highly branched structures within root cortical cells, giving rise to arbuscular mycorrhiza, which may produce extensive extramatrical hyphae and significantly increase phosphorus inflow rates in the plants they colonize. Ectomycorrhizal fungi may produce large quantities of hyphae on the root and in the soil; these hyphae play a role in absorption and translocation of inorganic nutrients and water, and also release nutrients from litter layers by producing enzymes involved in mineralization of organic matters. Over 4,000 fungal species, primarily belonging to Basidiomycotina and to a lesser extent Ascomycotina, are able to form ectomycorrhizae. Many of these fungi produce various mushrooms on the forest floor that are traded at a high price. In this paper, we discuss the benefits, nutrient cycles, and artificial cultivation of mycorrhizae in Korea.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1229-1235
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• 1998

To see the correlation between the rate of in vitro starch hydrolysis and the glycemic index, an in vitro digestion was carried out by incubating the cereal samples for 2 hours with ${\alpha}-amylase$ in dialysis tubing. Also the levels of blood glucose were measured over 2 hours after feeding healthy volunteers with 50 g carbohydrate portions. Hydrolysis area, hydrolysis index (HI) and the dialysate content of carbohydrate throughout the digestion time for barley was significantly below those for other cereals (p<0.05), and unpolished glutinous rice was significantly above (p<0.05). The GI-glucose of barley $(57%{\pm}7)$ to glucose as standard was significantly (p<0.05) lower than those of other cereals whereas the GI-glucose of glutinous rice $(110%{\pm}8)$ was significantly higher (p<0.05) than other cereals. The GI-rice values to rice as standard were $122%{\pm}4$ for glutinous sorghum, $116%{\pm}13$ for job's tear, $115%{\pm}13$ for glutinous millet, $106%{\pm}6$ for unpolished glutinous rice, $102%{\pm}7$ for glutinous rice, $100%{\pm}0$ for rice, $90%{\pm}12$ for unpolished rice, $85%{\pm}6$ for foxtail millet, $79%{\pm}5$ for buckwheat and $63%{\pm}6$ for barley. The GI-rice was significantly correlated to hydrolysis area and HI (r=0.75, p<0.01). It suggests that the in vitro starch hydrolysis offers good potential to predict the in vivo glycemic response of starch foods.

• Korean Journal of Food Science and Technology
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• v.42 no.1
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• pp.69-74
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• 2010

Black garlic has recently received significant attention due to its various health functional properties, and there has been an increase in demand for its use as a functional food. This study was performed to determine the optimum concentration for the fermentation of black garlic yakju. In addition, the antioxidant activity of the fermented black garlic yakju was examined. The alcohol content in the black garlic yakju significantly increased for 6 days and the pH gradually increased as the concentration of black garlic increased. The reducing sugar content at each black garlic concentration was maximal when it was fermented for 24 hours, and then rapidly decreased at longer fermentation periods. The main organic acids were lactic, citric, malic and oxalic acid. Also, the lactic acid content increased as the concentration of the black garlic increased where as the content of other organic acids decreased. The total polyphenol content, ferric ion reducing antioxidant power (FRAP) activity and DPPH (1,1-diphenyl-2-picryl-hydrazyl) free radical scavenging activity of black garlic yakju increased as the concentration of black garlic increased. The sensory characteristics of fermented black garlic yakju were evaluated in terms of color, flavor, taste and overall acceptability, and the highest overall acceptability value was obtained for yakju containing a black garlic concentration of 1-3%. Therefore, the optimum concentration of black garlic was determined to be 1% for the production of high quality black garlic yakju.

• The Korean Journal of Mycology
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• v.35 no.2
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• pp.81-84
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• 2007

In some cases, the problem with the mycelium of Tricholoma giganteum is delayed mycelial growth or non-regeneration. Therefore, this study was conducted to understand the mycelial storage condition of T. giganteum and to investigate the regeneration ratio of mycelial growth. T. giganteum obtained from KACC in RDA was evaluated for its simple preservation at $10^{\circ}C$ and subcultured on different media. Mycelium of T. giganteum was cultured on the PBA (potato bamboo extract medium) for seven days at $30^{\circ}C$. Using simple preservation method, the mycelium of T. giganteum (MKACC 50852) and Pleurotus ostreatus (Chunchu No. 2) were stored on six different media in two kinds of storage vessels (tube and vial) for a period of 1-12 months at $4^{\circ}C,\;15^{\circ}C$, and $25^{\circ}C$ storage temperatures. At $4^{\circ}C$ storage condition, mycelial regeneration was failed in all agar media, but was successful in the sawdust medium for 3 months. At $15^{\circ}C$ storage, mycelial activity was maintained up to six months. On the other hand, P. ostreatus produced well-regenerated mycelia both at $4^{\circ}C$ and $15^{\circ}C$ storage up to 12 months. In conclusion, it is estimated that the mycelia storage condition of T. giganteum must be done at $15^{\circ}C$ and subcultured within six months.

• Korean Journal of Food Science and Technology
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• v.49 no.4
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• pp.383-389
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• 2017

This study aimed to select a yeast strain for optimizing the quality of distilled spirits. The brewing and distilling properties of 4 KFRI (Korea Food Research Institute) yeasts (Y88-4, Y98-4, Y172-6, Y192-4) and 2 industry yeasts (C1, C2) were compared. For investigating the possibility of using these strains on an industrial scale, diverse analytical methods were applied to assess parameters associated with distilled spirit quality such as alcohol content, pH, total acidity, and soluble solid content. After 11 days of fermentation, the alcohol strength obtained using six yeast strains reached 13.9-16.4% (v/v), while pH was 3.9-4.0, and total acid was 0.40-0.52%. To compare GC-MSD Volatile flavor components, all the distilled spirit samples were diluted to 20% (v/v) alcohol strength. Seven fusel alcohols, 26 esters, 2 acids, and 3 miscellaneous compounds were detected in the distilled spirits. Y88-4 had the most abundant volatile flavor component and scored the highest overall preference in sensory evaluation. After analyzing the various properties of yeasts, strain Y88-4 was finally selected as the best strain for producing distilled spirits.

• Korean Journal of Food Science and Technology
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• v.50 no.1
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• pp.98-104
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• 2018

Oxyresveratrol (trans-2, 3', 4, 5'-tetrahydroxystilbene), found in many plants including grape, peanut and mulberry, is a phytoalexin, an antimicrobial and antioxidative substance that rapidly accumulates in areas infected by the pathogen. We examined the accumulation of oxyresveratrol in nine Morus alba L. cultivars with respect to storage time and temperature postharvest and infection with GRAS microorganisms. Among the nine cultivars, the Suwon cultivar showed the highest oxyresveratrol content (9.6-fold increase) postharvest, when stored at $30^{\circ}C$ for 7 days. The optimal temperature and postharvest storage time for oxyresveratrol accumulation was $30^{\circ}C$ and 6 days. When Ramulus mori was infected with five microorganisms, the accumulation of oxyresveratrol increased over 4-fold in response to B. coagulans infection. These results suggest that oxyresveratrol accumulation is influenced by storage temperature, storage time, Ramulus mori cultivars, and microbial attack. Therefore, postharvest storage for an appropriate time period at a suitable temperature might be a useful way to industrially produce Ramulus mori cultivars with high oxyresveratrol content.

• Korean Journal of Breeding Science
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• v.42 no.3
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• pp.267-271
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• 2010

A new black seed coat soybean cultivar, 'Daeheug', was developed at the National Institute of Crop Science (NICS) in 2007. The breeding goal for black seed coat soybean is to develop the cultivar with large seed size, high yield, lodging tolerance, and resistance to disease such as soybean mosaic virus (SMV), and bacterial pustule. 'Daeheug' was selected from the cross between 'Daehwang' which had yellow seed coat, large seed size, and late maturity, and 'Milyang 79' which was lodging tolerant, and SMV resistant with medium seed size, black seed coat, and yellow cotyledon. The preliminary, advanced and regional yield trials for evaluation and selection of this cultivar were carried out from 2003 to 2007. It has determinate growth habit, purple flower, brown pubescence, brown pod color, black seed coat, yellow cotyledon, spherical flattened seed shape, oval leaf shape and large seed size (34.3 g/100 seeds). In maturity, 'Daeheug' was 2 days later than the check cultivar 'Ilpumgeomjeongkong'. In the seed quality such as isoflavone contents ($635{\mu}g/g$), and anthocyanin contents ($11.2m{\ell}/g$ of seed coat), 'Daeheug' was better than the check cultivar. It has good adaptability for cooking with rice in ratio of water absorption and seed hardness. Specially, it has good processability for soybean tea with 2.13 absorbance at 530 nm, scavenge activity of DPPH radical was high, and contents of total phenolics was $1,263{\mu}g/m{\ell}$. The average yield of 'Daeheug' was 2.26 ton per hectare in the regional yield trials (RYT) carried out in six locations of Korea from 2005 to 2007.