• The Korean Journal of Mycology
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• v.31 no.1
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• pp.28-33
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• 2003

To establish the optimal fermentation periods in the manufacture of mushroom fermentation foods using sugar, changes of quality characteristics of the mushrooms fermentation broth were investigated with changes of enzyme activity and physiological functionality during fermentation. Viscosity, L value (lightness), a value (redness) and b value (yellowness) were significantly decreased after 3 months of fermentation and after that, increased. In sensory evaluation test, unique flavors and tastes of mushrooms in the fermented broth were decreased during fermentation, whereas the other tastes and flavors were gradually increased. Overall acceptability was the highest in the 3 months of fermentation broth. ${\alpha}-Amylase$ activities of the fermented broth were significantly increased to 1 month of fermentation, however invertase and cellulose activities were low or not detected in the fermented broth. Antioxidant activities were the highest in 4 months of fermentation and after that, decreased. Tyrosinase inhibitory activities were high in all samples and they were not changed during fermentation. SOD-like activity was high in the fermentation broth of Flammulina velutipes and it was also not changed during fermentation. In conclusion, optimal fermentation periods in the manufacture of mushroom fermentation foods using sugar was 3 or 4 months.

• Food Science and Preservation
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• v.23 no.1
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• pp.117-126
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• 2016

This study was performed to provide information for improving the quality characteristics of tangerine peel Soksungjang. Tangerine peel Soksungjangs were prepared with 10% tangerine peel powder by addition of different koji such as Rhizopus oligosporus (RS, RTS) and Aspergillus oryzae (AS, ATS). As a result, the moisture content was not changed and crude protein content decreased during fermentation in all samples. The pH of RS (Soksungjang manufactured with Rhizopus oligosporus koji) and RTS (Soksungjang manufactured with Rhizopus oligosporus koji and 10% tangerine peel powder) was not changed, whereas pH of AS (Soksungjang manufactured with Aspergillus oryzae) and ATS (Soksungjang manufactured with Aspergillus oryzae koji and 10% tangerine peel powder) decreased rapidly after 10 days of fermentation. The acidity values of all the samples increased during fermentation. The major free sugars were glucose, fructose, and maltose; while, the major organic acids were citric acid, succinic acid, acetic acid, and lactic acid in all the samples. The amino nitrogen content and protease activity were highest in the AS and ATS. Conversely, the reducing sugar content and ${\alpha}$-amylase activity were highest in the RS and RTS. The major free amino acids in all samples were glutamic acid, lysine, leucine, and arginine. Sixty kinds of volatile flavor compounds were identified from all samples; the majority of which were 21 alcohols, 14 hydrocarbons, 5 esters, and others identifies as acids, ketones, and aldehydes.

• Korean Journal of Veterinary Service
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• v.40 no.2
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• pp.119-131
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• 2017

Among different types of spoilage, microbial contamination can cause feed decomposition, which results in decreases in feed intake and productivity, infection, and breeding disorder. During the storage time, various microbes have a chance to inoculate with depreciation of feed and to infect the animals. We investigated bacteria that inhabit diverse feed ingredients and complete feed which have been stored for a few months. We isolated and identified 30 genera and 62 species of bacteria. Among these 62 species, 21 species were of non-pathogenic bacteria, 18 species were of pathogenic bacteria, 9 species were of opportunistic pathogens, and 14 species were of unknown bacteria. Pantoea allii and 24 species showed proteolytic enzyme activity. We also confirmed that 6 species including Pseudomonas psychrotolerans showed ${\alpha}$-amylase activity, and 29 species including Burkholderia vietnamiensis showed cellulase activity. Microbacterium testaceum and 3 species showed resistance to Ampicillin, Kanamycin, Streptomycin, Gentamicin, Carbenicillin, and Erythromycin ($50{\mu}g/mL$). Using mealworm larvae (Tenebrio molitor L.) as a model for pathogenicity, we confirmed that 8 species including Staphylococcus xylosus had pathogenicity for mealworm larvae. Especially, Enterobacter hormaechei, Staphylococcus xylosus, and Staphylococcus hominis were reported as being pathogenic for humans. This research suggests that hygienic management of animal feed is essential because beneficial and harmful bacteria can inhabit animal feed differently during storage and distribution.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.1
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• pp.76-82
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• 2009

Wheat is the most widely cultivated cereal and an important source of dietary protein worldwide. Wheat allergy, defined as an adverse immunologic reaction to wheat, encompasses a broad spectrum of disorders with different pathomechanisms and clinical manifestation. The Nuruk, a traditional Korean Koji for brewing, was made with wheat flour and fermenting microbes such as bacteria, yeast and mold. The strains grown on Nuruk secrete various enzymes as amylase and protease. By the activation of such enzymes, starch and proteins in Nuruk are hydrolyzed to sugar and amino acid. Therefore, it is supposed to reduce allergic proteins in wheat. To study quality properties and degradation degree of allergenicity in Nuruk by fermentation, we investigated the changes of general ingredients and allergenicity in Nuruk during fermentation. Moisture contents was decreased from 24.2% to 13.6% during fermentation. Crude lipid and protein contents were gradually increased during fermentation. After 15 days of fermentation, reducing sugar and total sugar contents were reached its maximum level, and they were 27.45% and 39.00%, respectively. Acid and neutral protease activity were significantly increased during fermentation, but alkaline protease activity was not detected. ${\alpha}$-amylase activity was gradually increased and showed maximum level about 2,833.00 U/g after 15 days of fermentation. Glucoamylase activity was the highest level about 497.9 U/g after 10 days of fermentation. The increase of these proteolytic and saccharogenic enzyme activities will provide efficient condition for production of rice wine. Also, protein fractions were isolated from Nuruk, and degradation of these proteins during fermentation were confirmed by SDS-PAGE. IgE immunoblotting using patient's sera with wheat allergy was performed to confirm allergenic protein in Nuruk. These results as fermentation of Nuruk will provide a useful tool for developing safer wheat products to prevent wheat allergy.

• The Korean Journal of Mycology
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• v.15 no.3
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• pp.158-168
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• 1987

Several species of the fungi were isolated from cassava(Manihot esculenta Gruntz) starch which had formed into pellet, those had been stored for a while in southern part of Thailand. The species of Rhizopus, Aspergillus niger, and Aspergillus fumigatus were identified. The experimental results are as follows; Dry weight increases were checked during the static liquid culture with modified Czapek Dox medium to which cassava starch was partly replaced to sugar, Aspergillus niger and Aspergillus fumigatus had grown more than Rizopus species when 6% cassava starch was replaced to sugar and had been cultured for 72 hours. Amounts of mycelial protein of Aspergillus niger were checked, the highest amount was shown in 6% cassava starch involved medium. When nitrogen sources were varied such as ammonium sulfate or urea against sodium nitrate, there was no significant difference in mycelial production. Alpha amylase activity of each fungus isolated here was checked, those of Aspergillus niger have shown the highest peak at 72 hours.

• Korean Journal of Food Science and Technology
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• v.35 no.1
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• pp.44-51
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• 2003

찹쌀가루와 메주가루의 배합비율(무게비)을 달리한 고추장(찹쌀가루 : 메주가루 = 1:1, 1:2, 1:3, 2:1, 3:1)의 숙성 중 품질 변화를 평가하기 위해 12주 동안 숙성시키면서 고추장의 이화학적 특성, 효소 활성 및 레올로지 특성을 연구하였다. 숙성 중 고추장의 수분함량은 $47.4{\sim}47.9%$에서 점차 증가하여 8주에는 최대 수분함량을 보였다. 환원당 함량은 $2{\sim}4$주에 가장 높았으며 이후에서는 점차 감소하는 경향을 보였다. 아미노태 질소 함량은 지속적으로 증가하였다. ${\alpha}-amylase$와 ${\beta}-amylase$ 활성은 숙성 $2{\sim}4$주에 최대 역가를 나타냈다. Acidic protease와 neutral protease는 각각 숙성 2주와 4주에 가장 높은 활성을 보였다. Power law 모델에 의한 유동성 측정에서 고추장은 낮은 유동성지수(flow behavior index, $n=0.21{\sim}0.36$)를 가진 전단담화(shearing-thinning)거동을 보여주었으며, 점조도 지수(consistency index, K)와 겉보기점도 $({\eta}_{a,10})$는 숙성 2주에 급격히 증가하고 이후에는 감소하였다. Casson 모델식에 의한 항복응력$({\sigma}_{oc})$은 숙성 2주에 급격히 증가하고 이후에는 감소하였다. 동적 점탄성 측정에서는 저장 탄성률 (G#)이 손실탄성률 (G') 보다 높은 수치를 나타내었고 주파수(frequency, ${\omega}$)가 증가함에 따라 증가하는 경향을 보여주었다. 또한 숙성기간이 경과함에 따라 (G#)과 (G@)이 증가하는 경향을 나타냈다.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.1
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• pp.96-104
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• 2009

Three kinds of grape yakju (Kyoho, Campbell and Moru) and grape-free control were fermented with rice using koji of Aspergillus kawachii as a fermenting agent, and their fermentation characteristics were investigated. For the three yakju, reducing sugar content decreased slowly over 2 days fermentation after an initial rapid decrease. In case of Brix, the reducing sugar content increased gradually after increasing rapidly during the first 2 days of fermentation. The Kyoho and Moru groups displayed a gradual increase in reducing sugar content after an initial 2-day decrease, and the sugar content of the Campbell group increased gradually during fermentation. Uniformly, pH increased gradually after an initial 2-day decrease, however total acid increased continuously throughout fermentation. Alcohol content of yakju showed almost no change after increasing until day 6 (Kyoho) of day 4 (others), with the control displaying the highest content. Control $\alpha$-amylase activity decreased gradually after an initial 2-day increase, while that of the three yakju decreased throughout fermentation. Activities of $\beta$-amylase activities paralleled the results of reducing sugar. Concerning total anthocyanin, the Moru and Campbell groups displayed a rapid increase until day 2, a decrease until day 12, and a gradual increase thereafter. While the Kyoho and control groups displayed virtually no change after an initial 2-day increase until day 12, after which a gradual increase also occurred. In concerning sensory evaluation, Moru yakju scored highest for violetness, flavor of grape, and sweet taste, and also displayed a low alcohol content. These attributed Moru yakju the preferred choice.

• The Korea Journal of Herbology
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• v.32 no.4
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• pp.47-52
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• 2017

Objective : Phellinus spp. mushroom is an object of interest because it has excellent anticancer effect. Owing to the similalarities in the morphology, Phellinus linteus and Phellinus baumii are often used as same Sang Hwang Mushroom in the Korean market.. The quality control for mushrooms is needed because there are many differences in the efficacy according to cultivation method and cultivation area. Therefore, a reliable authentication method of these herbal medicine is necessary to compare and measure the amount of beta-glucan which is known to have a hypoglycemic effect, from the mushrooms collected in various regions Methods : 7 samples of medicinal mushrooms supplying phellinus spp. were collected in Korea, China and Cambodia. We investigated the hardness, colors, extract ratio, ${\alpha}-amylase$ and ${\alpha}-glucosidase$ inhibitory activities, glucose transporter 4 (GLUT-4) expressions of water extracts from Phellinus spp and also MTT assay were examined for cell toxicity. Results : The results revealed that Phellinus spp.water Ext.inhibited ${\alpha}-glucosidase$ activity. glucose transporter 4 (GLUT-4), the key insulin signaling pathway transcription factor, was remarkably increased by the Phellinus baumii water extract Conclusions : These results suggest that The more yellowish the mushroom is, the lower the hardness, the more the content of ${\beta}-glucan$ is proportional. Because the more ${\beta}-glucan$, the greater the effect of hypoglycemia. compared to the hypoglycemic effect, Phellinus Baumii grown at hanging on selves for 7 month in the green house is the best.

• Microbiology and Biotechnology Letters
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• v.44 no.1
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• pp.98-105
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• 2016

The presence of bacterial strains showing antagonistic activity to common pathogens found in a variety of fermented foods in Korea was explored. A bacterium inhibiting the growth of pathogens such as Aspergillus terreus (KCTC6178), A. flavus (KCTC6984), Staphylococcus aureus (KCCM12214), Escherichia coli O157:H7 (KCCM40406), Bacillus cereus (KCTC1012), Cryptococcus neoformans (ATCC208821), Salmonella typhimurium (ATCC19430), and Listeria monocytogenes (KCTC3569) was isolated from Makgeolli, a Korean traditional rice wine. The strain showing high antipathogenic activity was identified as B. amyloliquefaciens based on the nucleotide sequence of the 16S ribosomal RNA gene. Compared with B. amyloliquefaciens KCTC1660, whose genome has been sequenced, the isolate exhibited significantly low activities of starch-degrading enzymes and high resistance to high temperature and low pH.

• Food Science and Preservation
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• v.20 no.6
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• pp.818-826
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• 2013

To evaluate the practical use of okara koji in soy sauce fermented with soybean koji, the okara koji was fortified with different contents (0, 50, and 100%) in soybean koji and then fermented for 90 days. The saltiness of the soy sauce was about 17.15~17.22%. The higher okara koji content showed lower net soluble solid contents of 8.73, 6.12, and 2.50%, as well as lower acidity levels of 1.09, 0.98, and 0.47%. The buffering capacity of the soy sauce decreased to 1.26-3.41 by adding higher okara koji. The protease activity was higher in the soy sauce with 50% orara koji and decreased with longer fermentation. Also, the tyrosine content peaked to 275.2 mg% after 90 days. ${\alpha}$-amylase showed higher activity in the soy sauces fortified with okara koji, which resulted in the highest total sugar and reducing sugar contents after 60 days. The total sugar and the reducing sugar in the soy source decreased after longer fermentation. The total free amino acid contents of the soy sources fortified with okara koji (0, 50, and 100%) were 41.68 mg/mL, 33.10 mg/mL, and 9.27 mg/mL, respectively. In particular, the glutamic acid contents of the three types of soy sauces were highest, and most amino acids, except for glutamine, increased during the fermentation for 90 days. The sensory evaluation, except of the saltiness and color, showed similar values in the soy sauces, except in the okara koji 100%. Thus, okara koji could be a valuable ingredient of traditional soy sauces. However, the 50% okara koji did not differ significantly from the others.