• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.1
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• pp.83-88
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• 2013

To improve kimchi qualities, Ecklonia (E.) cava of 5%, 15% or 25% were added and the qualities investigated by measuring changes in physicochemical, microbiological, and sensory characteristics during fermentation at $5^{\circ}C$. The pH of kimchi with E. cava added decreased and acidity increased. The number of Leuconostoc sp. in kimchi reached its maximum at the optimum fermenting stage, the $16^{th}$ day in control kimchi and the $20^{th}$ day in the kimchi added E. cava. The optimum fermenting stage of the kimchi was retarded due to adding the E. cava. The reducing sugar contents was highest in kimchi with 25% E. cava during the early stage of fermentation. According to Hunter's color values, the lightness of the kimchi with E. cava added decreased during fermentation, while the redness increased as fermentation proceeded. The sensory scores for overall acceptance, taste, texture and appearance were highest in kimchi with 15% E. cava.

• Korean Journal of Food Science and Technology
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• v.37 no.3
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• pp.449-455
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• 2005

To reduce saft content of kochujang, various combinations of sub-materials such as ethanol mustard and chitosan were added to kochujang, and their effects on microbial characteristics, enzyme activities, and physicochemical characteristics of kochujang were investigated after 12 weeks of fermentation. Activities of ${\beta}$-amylase and pretense were low in ethanol-mustard-chitosan-added kochujang, whereas no significant difference was observed in ${\alpha$-amylase activity among all groups. Number of viable yeast cells decreased remarkably in mustard-added kochujang during late aging period, and anaerobic bacterial counts decreased in sub-material-added groups. Consistency of kochujang increased by addition of sub-materials, and oxidation-reduction potential was low in chitosan-added group. Mustard-chitosan-added kochujang showed lowest increase in total color difference(${\Dalta}E$) and decrease in water activity. PH of kochujang wns highest in mustard-chitosan-added kochujang, resulting in significantly increased titratable acidity. Addition of sub-material increased reducing sugar contents of kochujang, whereas ethanol production was significantly repressed in mustard-chitosan-added kochujang. Amino nitrogen content was Highest in mustard-chitosan-added kochujang during late aging period, whereas ammonia nitrogen content was lower in ethanol-mustard-added kochujang. Results of sensory evaluation indicated ethanol-mustard-added kochujang was more acceptable than other groups in taste and overall acceptability.

• Korean Journal of Food Science and Technology
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• v.39 no.5
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• pp.515-520
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• 2007

To establish the roasting conditions of dandelion leaves for the manufacture of processed foods such as beverages and tea, we investigated the physicochemical and sensory characteristics of dandelion leaves and their hot water extracts by roasting treatment. As the number of roasting times increased, the free sugar content of the roasted dandelion leaves decreased, and in particular, free amino acid and total polyphenol content decreased greatly after only 1 roasting treatment. The amino nitrogen and total polyphenol contents of the roasted dandelion leaf hot water extracts also decreased greatly, and their L-, a-, and b-values showed much lower values than those of the raw leaf extracts. However, a greater amount of reducing sugars was extracted in the roasted leaves than in the raw leaves, suggesting that the roasting process allows for easier extraction of the compounds in dandelion leaves. Five sensory characteristics, including astringent taste, bitter taste, peen flavor, burnt taste, and sweet odor, were deduced through quantitative descriptive analysis of the hot water extracts. Among them, astringent taste, bitter taste, and green flavor showed significant differences between roasting treatments. The sensory evaluation results show that as the number of roasting times increased, the palatability of the hot water extracts increased greatly, in terms of color and taste.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.171-175
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• 1999

Changes in physicochemical characteristics of steamed rice during roasting were investigated. Steamed rice was roasted at various temperature $(150{\sim}220^{\circ}C)$ for various time $(10{\sim}30min)$. L and b Hunter color values of steamed rice were decreased, but E value was increased by roasting. The water absorption index and the water solubility index were gradually with increasing roasting temperature and time up to $200^{\circ}C$ for 30min, but decreased at $220^{\circ}C$ for 20min. The yield of water extracts from steamed and roasted rice were sharply increased with increasing roasting temperature and time, however, precipitates and turbidity were decreased. The content of reducing sugar was slowly increased up to $200^{\circ}C$ and remarkably increased above it. The contents of amino acids were decreased by roasting. Among them, cystine, lysine and serin were significantly reduced with increasing roasting temperature.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.176-182
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• 1999

Whole soybean cereal was fermented with four fungal strains (Mucor and Rhizopus) in pilot meju fermentation system. The pH range of the fermented soybean cereal was $7.16{\sim}8.38$, the contents of reducing sugar and amino-nitrogen were $0.54{\sim}2.64%,\;93{\sim}312mg%$, respectively, and that of free fatty acid ranged $0.06{\sim}2.00%$. The components of the amino acid, organic acid, free sugars and fatty acid showed distinctive patterns among four groups of fermented soybean cereals. Amylase activity and carbohydrate degradation rate of R. oryzae, protease and protein degadation rate of R. stolonifer was higher than other strains. But lipase and lipid degradation rates of four strains were similar. The odor concentrates of the soybean cereals fermented with Mucor strains were similar to Aspergillus strains, but Rhizopus were possessed of the flavor components of Bacillus and Aspergillus. Soysauce, made from M. hiemalis and R. stolonifer fermented soybean cereal showed excellent sensory evaluation and it was proposed that the two strains will be useful in Korean soysauce process.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.189-194
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• 1998

In order to evaluate the residual effects of bituminous coal fly ash, gypsum, oyster shell as soil amendments, Chinese cabbage was cultivated on acidic sandy loam soils with low boron content. The soils were amended in the upper 15cm with amendments in previous year and the growth and qualities of plants were analyzed. Amendments treated one year before were, in metric tons per hectare, i) none(Check) ; ii) 80 fly ash(FA) ; iii) 4 shell(SH) ; iv) 56 fly ash + 24 gypsum (FG) ; v) 40 fly ash + 24 gypsum + 0.8 shell(FGS). Yield response in fresh weight of Chinese cabbage was in order of 834% for FGS > 780% for FG > 755% FA > 193% for SH plants. Reducing sugar, vitamin-C, and total nitrogen contents of leaves depending on treatments showed the same tendencies as that in yields, whereas crude fibre opposite to them. In particular, FA, FG, and FGS plants showed normal growth without both boron deficiency symptoms which appeared in Check and SH plants and possibilities of accumulation of heavy metals. In any soils treated with the above amendments, however, magnesium was insufficient.

• Applied Biological Chemistry
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• v.29 no.2
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• pp.227-236
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• 1986

Three types of Kochujang(soybean-red pepper paste) were prepared with glutinous rice flour (group A), glutinous rice grain (group B) or the mixture of flour and grain (group C) to investigate some chemical composition, enzyme activities and the texture during aging period. 'There were no remarkable differences in the contents of moisture, crude protein, crude fat, minerals and alcohols, titrable acidity and pH among the tested groups. Amino nitrogen content, acidic protease and saccharogenic amylase activities were measured to be higher values for group A whereas reducing sugar content higher values for group B. All tested groups contained Ca, Cu, K, Mn, Mg, P and Fe, particularly higher amount of K but a trace of Cu, Mn and Fe. All tested groups showed higher content of aspartic acid, glutamic acid, cystine, proline and lower content of histidine and valine 60 days after the preparation. The total free amino acid content was 16.49 mg/g for group A, 13.68 mg/g for group B and 15.84 mg/g for group C. The measurement of texture showed high values of hardness and adhesiveness with group A immediately after the preparation and with group B at the end of aging. Cohesiveness and springiness were high with group A while low with group B throughout aging period.

• Food Science and Preservation
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• v.22 no.4
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• pp.545-552
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• 2015

This study investigated the quality characteristics of popped rice Doenjang prepared with different Bacillus strains (Bacillus subtilis KACC 15935, and Bacillus subtilis HJ18-9). The changes in the enzyme activity (protease, cellulase, and ${\alpha}$-amylase), amino-type nitrogen and ammonia-type nitrogen contents, and the reducing sugar were investigated during the fermentation period. Enzymes such as protease, cellulase, and a-amylase plays an important role in the changes in composition of nutrients, and in flavor and taste of popped rice Doenjang. Protease activities of the popped rice deonjang fermented with different Bacillus strains (control, B. subtilis KACC 15935, and B. subtilis HJ18-9) was in the range of 171.77-185.97 unit/g at the beginning of fermentation, and there were no significant differences among the samples. On the other hand, the protease activity in popped rice Doenjang fermented with B. subtilis HJ18-9 increased significantly up to $248.77{\pm}4.53unit/g$ at the end of fermentation (p<0.05). Cellulase activity and a-amylase activity of popped rice Doenjang in HJ18-9 was higher than these of other samples. After 56 days of fermentation, amino-type nitrogen in popped rice deonjang fermented with control, B. subtilis KACC 15935, and B. subtilis HJ18-9 increased significantly up to $174.99{\pm}3.70$, $166.59{\pm}1.40$, $225.39{\pm}3.70mg%$, respectively (p<0.05). These results suggested that B. subtilis HJ18-9 was a suitable starter for the preparation of soybean paste.

• Food Science and Preservation
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• v.23 no.4
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• pp.538-546
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• 2016

Kochujang was prepared by replacement of rice (25%, control) with pumpkin or purple sweet potato by 0. 5, 10, and 15% (total addition ratio of rice and sweet potato=25% of sample). Effects of the addition of sweet potato on physiochemical properties of fermented Kochujang were investigated. Viable cells of yeast decreased in the sweet potato-added Kochujang at the later stage of fermentation, while there was no significant difference in the number of bacteria among the test groups. As the addition ratio sweet potato increased, ${\alpha}$-amylase activity increased while protease activity decreased. Hunter L, a, and b values of Kochujang prepared with purple sweet potato were lower than those with pumpkin sweet potato. Changes in ${\Delta}E$ value was greater in Kochujang prepared with pumpkin sweet potato than that with purple sweet potato. Oxidation-reduction potential and water activity were higher in sweet potato-Kochujang than control, but reducing sugar content was higher in control. Alcohol and amino-type nitrogen contents were higher in Kochujang prepared with pumpkin sweet potato than that with purple sweet potato, but it was not significant. Overall sensory acceptability was highest in Kochujang prepared with 10% of purple sweet potato while that with 15% pumpkin sweet potato was the least preferred.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.851-859
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• 2000

In the present study, changes in physicochemical and sensory properties, and microflora and enzyme activities, by addition of pumpkin (1, 2 and 5% pumpkin on the weight basis), of Sunchang sikhe kochujang, the most famous traditional kochujang, were investigated. Moisture content appeared to be reduced during fermentation, possibly due to exposure to the sun. Patterns of pH changes were rather complicated. pH of control kochujang was gradually reduced from the begining of fermentation up to 60 days of fermentation. Thereafter, it tended to be increased but again reduced after 90 days of fermentation. On the other hand, titratable acidity increased with fermentation reaching at the highest level at 90 day of fermentation and then slowly decreased. The addition of pumpkin induced a reduction in pH and an increase in titratable acidity, but this was due to organic acid contained in pumpkin itself. Contents of reducing sugar and amino nitrogen were increased by the addition of pumpkin in relation to the level of addition. Ethanol content was highly increased by the addition of pumpkin. Bacterial and yeast count, and activities of amylase and protease were not affected by the addition of pumpkin. Sensory evaluation test revealed that the addition of pumpkin improved sweet and savory taste, but color turned to be undesirable. However, none of tested parameters except color showed statistical significance.