• KSBB Journal
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• v.6 no.1
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• pp.85-90
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• 1991

Experiments of alcohol fermentation of the yeast,K. fragi1is CBS 1555 were performed to obtain the following results. In these experiments, the initial concentrations of sugar which was composed of inulin and fructose as weight ratio of one to one were 30, 50, 75, 100 and 150g/l and the initial densities of the microorganism were less than 0.5g/l, 10g/1 to 15g/1, and 50g/l. The functional relationship among specific growthrates, sugar concentrations, and alcohol concentrations could be expressed by Aiba-shoda equation and the specific growth rate represented the trend that decreased with increase in the initial concentration of the microorganism. Also, $\mu$max and Ks of Monod's equation could be expressed as the function of initial cell concentration like the following equations. $\mu$max=0.8-0.008X Ks=0.54X+8 In the region that sugar, alcohol and cell concentrations were 10g/1 to 120g/l, 0g/l to 60g/l and 0.5g/l to 50g/l respectively, the differences between the experimental values and the calculated ones for specific growth rate approached to 40% with respect to experimental values at the worst cases, but in most cases, those were distributed in the range of less than 20%.

• Journal of the Korean Society of Food Culture
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• v.30 no.3
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• pp.370-376
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• 2015

In this study, we compared the organoleptic and other qualities of fermented milk containing 10 or 15% purple carrot extract that had either been previously fermented with Aspergillus oryzae or not fermented. Fermentation characteristics, pH, chromaticity, viscosity, viable cell counts, and sensory evaluations were measured. The pH and acid values did not differ between purple carrot extract fermented with Aspergillus oryzae and non-fermented extract. Viable cell counts were significantly higher in 15% purple carrot extract fermented with Aspergillus oryzae compared to the control after fermentation. Regarding characteristic changes, purple carrot extract fermented with Aspergillus oryzae group showed a lower red value but higher yellow value compared with non-fermented purple carrot extract due to heat-sterilization. Both fermented and non-fermented extract groups showed significantly increased viscosity compared to control. In the sensory evaluation, 15% purple carrot extract fermented with Aspergillus oryzae showed the highest score. In conclusion, addition of 15% purple carrot extract fermented with Aspergillus oryzae resulted in a superior fermented milk product.

• Korean Journal of Food Science and Technology
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• v.47 no.1
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• pp.51-55
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• 2015

Four varieties of the Korean sweet potato, Yeonmi, Jeungmi, Shincheonmi, and Shinyeulmi, were chosen to prepare the distilled koguma-soju (sweet potato-soju). The relationship between the flavor of the koguma-soju and the content of monoterpene alcohols (MTAs) was studied. The MTAs investigated here were linalool, nerol, geraniol, citronellol, and ${\alpha}$-terpineol. The ranges of MTA concentrations in the koguma-soju made from the four sweet potato varieties were $14.0-16.6{\mu}g/L$ for nerol, $24.8-34.7{\mu}g/L$ for linalool, $32.8-38.5{\mu}g/L$ for geraniol, $37.8-54.2{\mu}g/L$ for citronellol, and $76.6-94.7{\mu}g/L$ for ${\alpha}$-terpineol. Geraniol, nerol, and linalool were found in lower concentrations, while ${\alpha}$-terpineol was present in a higher concentration compared to their average content in the imo-shochu, a distilled Japanese sweet potato-soju. The concentrations of citronellol in the koguma-soju and imo-shochu were similar. The flavor evaluation tests revealed that the koguma-soju produced from the Yeonmi variety had a leafy vegetable or a grass-like, sharp flavor, whereas the Jeungmi-soju was characterized by a fruity or a sulfur-like sharp taste. Floral, vanilla-like, and mild flavors were predominant in the Shincheonmi-soju, while the Shinyeulmi-soju had either a fruity, citrus-like flavor or a rubber-like, rough taste. This study demonstrates that koguma-soju made from different sweet potato varieties have unique characteristic flavors.

• Journal of Animal Science and Technology
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• v.47 no.3
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• pp.409-418
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• 2005

This study was conducted to examine the nutrient digestibility and ruminal fermentation characteristics in sheep fed dried mugwort and mugwort silage for 5% levels of rice straw in the basal diet, and mugwort pellet for 5% levels of concentrate in the basal diet. For the experiment, they were given a basal diet containing of rice straw and concentrate mixed at a 3: 7 ratio (DM basis). The treatments were designed as a 4 ${\times}$ 4 Latin square design with four sheep (50.2 kg body weight). The digestibility of crude protein was increased (p < 0.05) to 4.6 - 6.2 % in sheep fed mugwort silage treatments (60.23 %) compared with those of control (54.08 %) and dried mugwort treatment (55.67 %). That of ether extract was iicreased (p < 0.05) to 4.8 - 8.8 % in sheep fed mugwort silage treatments (80.22 %) compared with those of control (71.47 %) and dried mugwort treatment (75.46 %). In the dry matter intake, mugwort silage treatment (904.44 g) was the hightest and mugwort pellet treatment, dried mugwort treatment and control were 810.66 g, 780.66 g and 742.18 g, respectively. The ruminal pH in all treatments were rapidly decreased (p < 0.05) at 0.5 and 1 hour after feeding and slowly increased at 2, 4 and 8 hours after feeding, especially mugwort silage treatment. The ammonia nitrogen concentrations were the highest (p < 0.05) in sheep fed mugwort silage treatment (11.24 - 12.05mg / 100 rnz) at 0.5 and 2 hours after feeding. The ruminal concentrations of acetic acid (6.06 mmol /100 $m\ell$) and propionic acid (2.35 mmol/ 100 mz) were an increased (p < 0.05) at the mugwort silage treatments at 1 and 2 hours after feeding. Purine derivatives out put (13.41 mmol / d) and microbial protein production (11.61 mmol / d) were increased (p < 0.05) compared with those of control (5.42 and 4.93 mmol / d).

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.9
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• pp.1274-1280
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• 2015

This study was conducted to assess the effects of microbial and chemical combo additives on nutritive values, fermentation indices and aerobic stability of whole crop barley silage. Barley forage (Youngyang) was harvested at about 30% dry matter (DM) by treatments, chopped to 5 cm length and treated with distilled water only (CON), Lactobacillus plantarum (INO), propionic acid (PRO) or an equal mixture of INO and PRO (MIX). Barley forages were ensiled in 4 replications for 0, 2, 7, and 100 days. On 100 days of ensiling, MIX silage had higher (p<0.05) in vitro DM digestibility than CON silage, but lower (p<0.05) acid detergent fiber concentration. The pH in all treated silages was lower (p<0.05) than CON silage. The MIX silage had higher (p<0.05) lactate concentration and lactate to acetate ratio than in CON, but lower (p<0.05) yeast count. Aerobic stability in CON, PRO, and MIX silages were higher (p<0.05) than in INO silage. It is concluded that microbial and chemical combo additives using L. plantarum and propionic acid could efficiently improve nutritive values of barley silage in terms of increased in vitro DM digestibility compared to other treatments. In addition, all treatments except CON reduced yeast count which is the initiate microorganism of aerobic spoilage.

• Journal of Microbiology and Biotechnology
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• v.28 no.11
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• pp.1865-1875
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• 2018

Enhanced application of solid-state fermentation (SSF) in industrial production and the influence of SSF of Rhizopus K1 on glucoamylase productivity were analyzed using the flat band method. A growth model was implemented through SSF of Rhizopus K1 in this experiment, and spectrophotometric method was used to determine glucoamylase activity. Results showed that in bran and potato culture medium with 70% moisture in a loose state, ${\mu}$ of mycelium reached to $0.15h^{-1}$ after 45 h of culture in a thermostatic water bath incubator at $30^{\circ}C$. Under a low-magnification microscope, mycelial cells appeared uniform, bulky with numerous branches, and were not easily ruptured. The generated glucoamylase activity reached to 55 U/g (dry basis). This study has good utilization value for glucoamylase production by Rhizopus in SSF.

• Journal of Microbiology and Biotechnology
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• v.26 no.6
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• pp.999-1010
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• 2016

Ganoderma lucidum BCCM 31549 has a long established role for its therapeutic activities. In this context, much interest has focused on the possible functions of the (1,3)-β-D-glucan (G) produced by these cultures in a stirred-tank bioreactor and extracted from their underutilized mycelium. In the existing study, we report on the systematic production of G, and its sulfated derivative (GS). The aim of this study was to investigate G and its GS from G. lucidum in terms of their antibacterial properties and cytotoxicity spectrum against human prostate cells (PN2TA) and human caucasian histiocytic lymphoma cells (U937). ¹H NMR for both G and GS compounds showed β-glycosidic linkages and structural similarities when compared with two standards (laminarin and fucoidan). The existence of characteristic absorptions at 1,170 and 867 cm^-1 in the FTIR (Fourier Transform Infrared Spectroscopy) for GS demonstrated the successful sulfation of G. Only GS exhibited antimicrobial activity against a varied range of test bacteria of relevance to foodstuffs and human health. Moreover, both G and GS did not show any cytotoxic effects on PN2TA cells, thus helping demonstrate the safety of these polymers. Moreover, GS showed 40% antiproliferation against cancerous U937 cells at the low concentration (60 μg/ ml) applied in this study compared with G (10%). Together, this demonstrates that sulfation clearly improved the solubility and therapeutic activities of G. The water-soluble GS demonstrates the potential multifunctional effects of these materials in foodstuffs.

• Korean Journal of Food Science and Technology
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• v.51 no.1
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• pp.7-11
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• 2019

Reverse osmosis (RO) was applied to onion juice to produce concentrated onion juice with improved flavor. The volatile compound profiles of concentrated onion juice and onion juice were compared using solvent-assisted flavor evaporation followed by gas chromatography-mass spectrometry. Onion juice and RO-concentrated onion juice contained 48 and 62 distinct volatile compounds, respectively, and included alcohols, aldehydes, esters, terpenes, furans, ketones, acids, hydrocarbons, and sulfur-containing compounds. The RO-concentrated onion juice contained a greater number of volatile flavor compounds than did onion juice. Notably, sulfur-containing compounds, which are characteristic volatile flavor compounds in raw onions, were more abundant in the RO-concentrated onion juice than in onion juice. The volatile compound composition indicates that RO-concentration produces good quality onion juice.

• Journal of Microbiology and Biotechnology
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• v.32 no.3
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• pp.307-316
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• 2022

Yeasts play an important role in spontaneous fermentation of traditional alcoholic beverages. Our previous study revealed that a mixed-consortia of both Saccharomyces and non-Saccharomyces yeasts were responsible for fermentation of khadi, a popular, non-standardized traditional beverage with an immense potential for commercialization in Botswana. Functional characterization of isolated fermenting yeasts from mixed consortia is an indispensable step towards the selection of potential starter cultures for commercialization of khadi. In this study, we report the characterization of 13 khadi isolates for the presence of brewing-relevant phenotypes such as their fermentative capacity, ability to utilize a range of carbon sources and their ability to withstand brewing-associated stresses, as a principal step towards selection of starter cultures. Khadi isolates such as Saccharomyces cerevisiae, Saccharomycodes ludwigii and Candida ethanolica showed good brewing credentials but Lachancea fermentati emerged as the isolate with the best brewing attributes with a potential as a starter culture. However, we were then prompted to investigate the potential of L. fermentati to influence the fruity aromatic flavor, characteristic of khadi. The aroma components of 18 khadi samples were extracted using headspace solid phase micro-extraction (HS-SPME) and identified using a GC-MS. We detected esters as the majority of volatile compounds in khadi, typical of the aromatic signature of both khadi and L. fermentati associated fermentations. This work shows that L. fermentati has potential for commercial production of khadi.

• Journal of the Korean Society of Food Culture
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• v.1 no.3
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• pp.267-278
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• 1986

The evolution of Korean fish fermentation technology was reviewed from the old literatures and the on-going processes were surveyed. The principles involved in the traditional fermentation methods were explained by the recent scientific findings. The fish fermentation technology be classified into two groups; jeot-kal process, where. salt is the only material added to the fish for fermentation, and sik-hae process, where cooked cereals, garlic and red pepper powder are added to the salted fish. A total of 46 kinds of jeot-kal was identified in a survey, depending on the raw materials used. The characteristic feature of Korean jeot-kal process is to produce fermented products which still has original shape after 2-3 months of fermentation to be used for side-dishes of rice meal, as well as fish sauce by keeping these products for longer time (over 6 months) for severe ansymematic hydrolysis to be used for the subingredient of Kimchi (Korean fermented vegetable food). The taste of jeot-kal is formed by the protein hydrolymates due to the action of salt-tolerant Pediococcus, Bacillus, Halobacterlum etc. When the taste of jeot-kal deteriorates, yeasts appear to dominate. In ski-hae fermentation, the safety of preserved fish is kept by the rapid decrease in pH resulting from the acid fermentation of added cereals. The roles of cid forming bacteria and proteloytic bacteria are important. The fermentation is completed in 2 weeks and the excess production of acid during prolonged storage limits the taste acceptability. The fish fermentation technology in Korea stands at important position in Korean food science and technology. since the processes of jeot-kal and soysauce have same root in the principle of microbial proteolysis and the processes of sik-hae and Kimchi in the microbial acid production principles.