• Korean Journal of Food Science and Technology
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• v.50 no.2
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• pp.123-131
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• 2018

The objective of this study was to evaluate the effect of roasting degree of barley on aroma characteristics of boricha (barley tea) using solvent-assisted flavor evaporation-gas chromatography-mass spectrometry and gas chromatography-olfactometry. Fifteen volatile compounds including pyrazine, ethylpyrazine, butyrolactone, and guaiacol were considered important volatile compounds, which are generated by roasting barley, because concentrations of those volatiles were significantly increased (p<0.05) as roasting degree of barley was darker. Guaiacol (smoky), furfuryl alcohol (burnt sugar), and furfural (caramel) were detected as aroma-active compounds of boricha with high intensity. Aroma intensity of aroma-active compounds in boricha increased with increase in roasting degree of barley. However, one unknown compound with burnt smell was detected as off-flavor in dark roasted barley. Therefore, it is implied that medium roasting of barley is desirable during boricha manufacturing. Furthermore, boricha manufactured with steamed barley contained more abundant volatile flavor compounds, which may lead to better aroma quality of boricha.

• Applied Biological Chemistry
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• v.13 no.1
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• pp.35-42
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• 1970

Five samples of Korean native Maeju(fermented soy-bean mash) loaves which were collected each from Kyunggi, Chungchung, Kangwon, Cholla and Kyungsang-Do were examined for their fermenting microorganisms. The results of taxonomic and ecological studies of fermentation microorganisms in these Maeju loaves were as the fellows. (1) The fungus flora grew only is the outer layer of Maeju loaves. Miscellaneous molds, 3 species of Mucor, 2 species of Pericallium., one species each of Scopulariopsis and Aspergillus, were isolated. None of them seemed exclusively predominant to be able to designate as the ecologically significant. (2) The bacterial flora which consisted of two species, Bacillus subtilis and Bacillus pumilus were distributed uniformly in th a entire Maeju loaves. The inner parts of Maeju loaves were especially inhabited solely by these bacterial flora. Probably the Korean native Maeju fermentation could be characterized by these bacterial flora. A Staphylococcus species was also isolated probably as a casual contaminant. (3) The yeasts, Rhodotorula flava and Torulopsis dattila, were isolated from Maeju loaves though their ecological significance was not clear. (4) The ecological aspects of fermentation microbes in the outer and inner parts of Maeju loaves were apparently different, consequently different fermentation processes might have occurred in these two parts and it brought quite different final outlooks in the final matured Maeju loaves. The outer part, rather rigid and dry, retained the light brown color of boiled soy-bean; whereas the inner part, soft and sticky, showed dark brown color indicating severe chemical changes. (5) The aflatoxin producing mold, Aspergillus oryzae was isolated from one sample among 5 of Maeju loaves. In addition to the low probability of isolability from Maeju loaves samples, since this mold grew only in the outer layer of Maeju loaves with such a low population density, about $10^4/g$, perhaps the aflatoxin problem in Korean native soysauce may not be critical.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.1
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• pp.78-86
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• 2012

In this study, dark fermentative hydrogen production (DFHP) from acid pretreated microalgal biomass was optimized with via statistical experimental design. Acid concentration and reaction time were varied from 0.1 to 3% (v/w) and 10 to 60 min with substrate concentration of 76 g dry cell weight (dcw)/L and initial pH of 7.4, respectively. During the fermentation, pH was not controlled. The optimal condition was found that at $H_{2}$ yield reached to 37.3 mL $H_{2}/g$ dcw at 1.2% HCl and 48 min. Through regression analysis, it was found that $H_{2}$ yield was well fitted by a quadratic polynomial equation ($R^{2}$=0.95). HCl concentration was the most significant factor influencing DFHP. The results of ANOVA verify that HCl concentration was the most significant factor influencing DFHP.

• Journal of Life Science
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• v.18 no.10
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• pp.1420-1425
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• 2008

This study was conducted to investigate the fermentation characteristics of cheonggukjang prepared with soybean germinated under light condition. The moisture content and pH of cheonggukjang made with soybean germinated under light condition (CGL) were higher than that of cheonggukjang made with non-germinated soybean (CNG). The color of CGL was darker than that of CNG and cheonggukjang made with soybean germinated under dark condition (CGD). The number of live bacteria in the CGL ($10.7{\pm}0.3\;\log\;CFU/g$) and CGD ($10.7{\pm}0.4\;\log\;CFU/g$) was higher than that of CNG ($9.7{\pm}0.4\;\log\;CFU/g$). The levels of isoflavone in CGL, CGD and CNG were 2,038.0, 1,993.6 and 1,747.0 ug/g, respectively. There were no significant differences in the appearance, aroma, taste and overall acceptability of the cheonggukjang made with different germination conditions. Therefore, it was expected that the cheonggukjang prepared with soybean germinated under light condition could be practically used as a new fermented food.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.1
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• pp.10-19
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• 1986

A study on the rapid fermentation of fish sauce has been carried out for effective utilization of sardine. The frozen sardine was thawed at room temperature, chopped, homogenized with equal amount of water and then hydrolyzed by addition of commercial proteolytic enzymes such as bromelain, papaya protease, ficin and a enzyme mixture under different conditions of hydrolysis. The effect of wheat gluten for masking fishy odor and color development during thermal treatment were also tested. The reaction mixture was heated for 30 minutes at $100^{\circ}C$ for enzyme inactivation, pasteurization and color development and then centrifuged for 20 minutes at 4,000 rpm. Finally, table salt and benzoic acid were added for bacteriostatic effect. The results were summarized as follows ; 1. The hydrolyzing temperature, time, pH and the concentration of enzymes based on the weight of whole sardine for optimal hydrolysis were as follows: autolysis, $52.5^{\circ}C$, 4 hours, pH 8.0: with $0.25\%$ bromelain, $52.5^{\circ}C$, 4 hours, pH 6.6 :with $0.25\%$ ficin, $52.5^{\circ}C$, 4 hours, pH 6.8: with $0.3\%$ papaya protease, $52.5^{\circ}C$, 4 hours, pH 6.6: with $6\%$ enzyme mixture, $52.5^{\circ}C$, 4 hours, pH 6.9, respectively. But pH control was not much beneficial in increasing yield. 2. The hydrolytic reaction of chopped sardine with proteolytic enzymes could be interpreted as a first order reaction that devided into 2 periods with different reaction rate constsnts. $Q_{10}$ values of the first period prior to 4 hours were 1.23 to 1.31, and those of post 4 hours were 1.25 to 1.55. The corresponding activation energies were $1.81{\times}10^4\;to\;2.34{\times}10^4\;kJ/kmol$ and $1.92{\times}10^4\;to\;3.77{\times}10^4\;kJ/kmol$, respectively. 3. The reasonable amount of $75\%$ vital wheat gluten for addition was $9\%$ of chopped sardine. 4. The dark brown color was mainly developed during the thermal treatment for 30 minutes at $100^{\circ}C$ and not changed during storage.

• Food Science and Preservation
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• v.17 no.1
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• pp.50-57
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• 2010

To develop a new functional kimchi with antioxidative properties, salted baechu was soaked in black rice water extract for 6 h at room temperature. The antioxidative property of the water extract was $78.75{\pm}1.18%$ that of the control (0.1% [w/v] alpha-tocopherol). The black rice gel was added to the baechu kimchi preparation. The color of baechu kimchi treated with black rice water extract changed to dark violet and/or black. Control kimchi and black rice water-treated kimchi were stored at $4^{\circ}C$ for 30 days. No significant differences were detected between the control and the black rice water-treated group in the early stages of fermentation. As fermentation time increased, pH decreased and titratable acidity increased rapidly in control kimchi. However, such marked changes were not evident in test kimchi. The hardness value of black rice water-treated kimchi was higher than that of control kimchi after the midpoint of the fermentation period. The storage life of baechu kimchi treated with black rice water extract was prolonged by up to 5 days compared with control samples, owing to a decline in lactic acid bacteria and yeast levels during the final fermentation period in black rice water-treated kimchi. The total phenolic levels and the antioxidative capacity of black rice water-treated kimchi (83%) were approximately 1.5-fold higher than in control kimchi (57%). In sensory evaluation, black rice water-treated kimchi scored higher than did control kimchi using a blind test protocol.

• Journal of the East Asian Society of Dietary Life
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• v.14 no.3
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• pp.275-282
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• 2004

The quality characteristics of baguette bread added with water extracts of Liriopis tuber(LT) and effect of the diets containing 20% dried and powered baguette with 10% LT on the level of blood sugar and lipids in the diabetes induced rat by streptozotocin were investigated. pH of the dough added with 5∼10% LT was 5.00∼5.03 which were lower than that of control(5.12). The volume of the dough with 10% LT after 2nd fermentation was the biggest. Loaf volume index of the bread with 10% LT was significantly higher than that of control. $L^{*}$ values of outside and inside of the baguette decreased in proportion to the increase of the LT, while the $a^{*}$ values increased. Color of the bread with LT showed light dark-red. There was no significant difference in hardness, but springiness and gumminess were higher in the bread with 10% LT. Sweet taste increased, color acceptability and overall taste were enhanced by addition of LT, but it did not affect the sour and astringent taste. The overeating phenomenon showed in the diabetes rat decreased in the group fed with baguette bread with LT, while feed efficiency increased by feeding of the bread with LT. The level of glucose, neutral lipid and total cholesterol in blood were 118.92,95.47 and 37.42mg/dL in the control group, 245.60, 121.54 and 102.43 mg/dL in the diabetes control, 148.40, 103.25 and 57.63 mg/dL in the baguette diet group, respectively. There was no significant difference of HTR between control group and baguette diet group, while atherogenic index was considerably decreased, which might represent improving and preventing effects of diabetes.s.s.

• Korean Journal of Food Science and Technology
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• v.25 no.2
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• pp.98-104
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• 1993

In order to improve qualities of kochujang, various fruit juices such as apple, orange, pineapple and grape were added to the raw material of kochujang instead of the part of water. It was apparent in the kochujang with pineapple juice that organic acids originated from fruit juices increased titrable acidity and decreased pH. Free sugars and organic acids in the kochujang that was fermented during three months were degraded or might be used by microorganism after ten months of fermentation. Kochujang with grape juice showed relatively dark color, which had a good agreement with the changes of Hunter a-value. Sensory evaluation test about tastes, flavor and color showed that the kochujang with pineapple juice was preferred to others.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.3
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• pp.259-272
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• 2020

Nowadays, two types, Yumhae and Sikhae methods, remained as traditional seafood fermentation methods in Korea. In this study, flavor compounds in two types of salt-fermented fishes made by Yumhae method such as anchovy Engraulidae sp., shrimp Caridea sp., squid Decapodiformes sp., big eyed herring Clupea sp., gizzard shad Dorosoma sp. and hairtail Trichiurus sp., and made by Sikhae method such as Alaska pollack Gadus Chalcogrammus and squid. Volatile compounds detected in all salt-fermented fishes were composed mainly of aldehydes (45), ketones (39), alcohols (45), acids (12), esters (47), N-containing compounds (43), aromatic hydrocarbons (37), S-containing compounds (26), furans (10), and miscellaneous compounds (40) in salt-fermented fishes made by Yumhae method. Meanwhile, alcohols (47), terpenes (38), S-containing compounds (22), carbonyl compounds (19 aldehydes, 18 ketones), esters (13), and acids (14). Aroma-active compounds were identified by Gas chromatography/mass spectrometry/olfactometry and aroma extract dilution analysis in salt-fermented anchovy, shrimp and tuna (Thunnini sp.) sauce. Ethyl 2-methylbutanoate (candy/sweet) and 2-ethyl-3,5-dimethylpyrazine (nutty/baked potato-like) were predominant odorants in salt-fermented anchovy, whereas dimethyl trisulfide (cooked cabbage/soy sauce-like), 2-ethyl-3,5-dimethylpyrazine, and (E,E)-2,4-heptadienal (fatty/grainy) in salt-fermented shrimp, and dimethyl trisulfide, 3-methylbutanal (dark chocolate-like), and 3-methylthiopropanal (baked potato-like) in tuna sauce.

• The Journal of the Korean Society for Microbiology
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• v.13 no.1
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• pp.25-30
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• 1978

Among clincal isolates, most strains of Serratia marcescens were belonged to nonpigmented form, and several attempts were undertaken for the rapid and simple identification of these strains. Prodigiosin production of non-pigmented strains was uniformly negative in many kinds of solid media as well as in nutrient agar added with various amino acids and thiamine. On blood agar, colonies of S. marcescens turned gradually to grey or dark color by the lapse of incubation period and this characteristic seems to be able to utilize as an indicator for a primary isolation, and also generally paralleled with the results of dehydration of Tween 80 and lipase activity in soy bean oil medium although these reactions were by no means specific to S. marcescens. In order to rule out these non-specific reactions, other tests such as oxidase and sucrose fermentation are required for the final confirmation of this species.