• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.238-245
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• 2000

This study was investigated to compare the changes of flavors in sesame oil with roasting temperature $(110^{\circ}C{\sim}230^{\circ}C)$. In the results of analyzing the volatile flavor compounds of sesame oil with GC and GC/MS, 26 pyrazines, 11 pyridines, 9 thiazoles, 6 furans, 8 pyrroles, 5 phenols, 8 aldehydes, 8 hydrocarbons, 7 alcohols, 2 indoles, 3 ketones, 10 acids, 4 nitriles, 7 esters, and 5 others were isolated, identified, and quantified. The total amount of flavor compounds was increased with roasting temperature. Detected flavors could be devided into top(peak No. $1{\sim}91$), middle$(92{\sim}197)$ and last note$(198{\sim}224)$ by rentention time. The top notes(initial content 19.87 ppm) which contain pyrazines and provide representative roasted flavors were increased significantly with roasting temperature. Initial content of middle note(17.72 ppm) was increased to 36.71 ppm at $170^{\circ}C$, to 95.61 ppm at $220^{\circ}C$, and to 138.62 ppm at $230^{\circ}C$. Last note was almost unchanged up to $170^{\circ}C$ and increased at $190^{\circ}C$, whereas it indicated a tendency to decrease at $230^{\circ}C$. Pyrazines such as methylpyrazine, 2,5-dimethylpyrazine, 2,6-dimethylpyrazine, trimethylpyrazine, 2-ethyl-3,5-dimethylpyrazine which indicate the major components among volatile flavors were increased slightly up to $150^{\circ}C$ and revealed the higher increase than any other components above $170^{\circ}C$. This tendency was also similar to pyridines, thiazoles, and furans. Most of these compounds are assumed to be developed by thermochemical reactions of sesame components by roasting above $170^{\circ}C$. It seemed that a lot of increase in phenols above $210^{\circ}C$ resulted from the production of guaiacol. Acids were almost unchanged up to $190^{\circ}C$, increased at $210^{\circ}C$, and then decreased above $220^{\circ}C$. It seemed to be resulted from pyrolysis of free fatty acids formed from thermal oxidation of oil.

• Korean Journal of Food Science and Technology
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• v.10 no.3
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• pp.337-343
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• 1978

In order to develope a new kind of fermented milk, basic studies on several lactic acid bacteria and yeasts were conducted, 8 kinds of alcohol fermented milk were manufactured and sensory evaluation was undertaken. The results obtained are summarized as follows: 1. Four kinds of lactic acid bacteria were isolated, among which Y-2 strain was strongest in acid productivity and it was elucidated that acid productivity of all strains was stornger in synthetic medium than in milk medium. 2. The pH in milk medium inoculated with Y-2 strain and incubated at $30^{\circ}C$ for 24 hours was dropped from 5.8 to 3.8 and fluctuation in amino nitrogen content was found during incubation. 3. The pH in milk medium inoculated with K. fragilis and incubated at $30^{\circ}C$ for 7 days was dropped from 6.2 to 5.2 and amino nitrogen content was in the range of $0.12{\sim}0.27mg/ml$. Alcohol productivity of K. fragilis was stronger than E-2 and E-4 strain but no difference in alcohol productivity was found between milk medium and synthetic medium. 4. The repression in growth and acid productivity of lactic acid bacteria was recongnized if inoculated after inoculating yeast firstly. 5. Alcohol productivity was increased rapidly at the end of acid production of lactic acid bacteria if lactic acid bacteria if lactic acid bacteria and yeast were inoculated simultaneously. 6. Sensory evaluation showed that the product that alcohol content and acidity were 1% and 0.8% respectively had the best palatability(p<0.01). 7. Chemical composition of final product was similar to that of milk koumiss in ash, protein and moisture content.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.7
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• pp.860-865
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• 2006

This study was performed to investigate the effect of ethanol and citric acid-treated anchovy, caseino-phosphopeptides (CPPs), calcium lactate, and calcium phosphate as dietary calcium supplements on calcium metabolism in rats for 5 weeks. Experimental animals were randomly assigned to five treatments with 15 heads of SD male rats (mean body wt. of 100 g) in each group. The experimental diets were as follows; dried large anchovy powder (C) as control, ethanol+citric acid group (EC), ethanol+citric acid+cpps group (ECC), calcium lactate group (CL) and calcium phosphate group (CP), which were formulated with commercial semi-purified Chow diet, while maintaining the same level of calcium in all diets (1%) groups. The weight gain of EC group was significantly higher than ECC, CL and CP groups (p<0.05), food efficiency (FER) was not different. In vitro and in vivo calcium absorption rates of ECC group treated with citric acid and CPPs were 20.4 and 28.4%, respectively, and the highest among the experimental groups (p<0.05). The blood glucose levels of CL group (105.7 mg/dL) was significantly higher than control group (98.5 mg/dL). In terms of serum lipids, total-cholesterol concentration of EC group (75.1 mg/dL) was significantly higher than CP group (65.6 mg/dL) and triglyceride concentration of CP group (33.5 mg/dL) was the lowest (p<0.05). ALP activity and 057 level were not different among experimental groups. The serum calcium concentration of control group (C) was the lowest among groups (p<0.05). The femur weight of CP group was the lowest (p<0.05) and the femur length of ECC group is the longest (P<0.05). The bone density of CP group $(0.1116\;g/cm^2)$ was the lowest while ECC group $(0.1149\;g/cm^2)$ was the highest, and the bone density was increased by added CPPs. These data demonstrated that ECC group significantly increased in vitro and in vivo calcium absorption rate, serum Ca level, and the length and bone density of femur.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.6
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• pp.896-903
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• 2015

The objective of this study was to investigate the effect of nitrite substitution of sausage with purple sweet potato by examining the quality characteristics of sausage. Four sausage samples were prepared as follows: F1 (0.15% sodium nitrite), F2 (0.2% pigment), F3 (0.2% pigment and 5% powder), and F4 (0.2% pigment and 10% powder). A substitution of sodium nitrite with 0.2% purple sweet potato pigment reduced redness while increased yellowness. However, the addition of 5% purple sweet potato powder to 0.2% purple sweet potato pigment increased redness while reduced yellowness, which was similar to those of sausage with 0.15% addition of sodium nitrite. Further, color change increased as the content of purple sweet potato increased. As the amount of purple sweet potato increased, the contents of Ca, K, and Mg increased but hardness, gumminess, and chewiness decreased. In the sensory evaluation, the addition of purple sweet potato did not influence on appearance, color, or flavor. However, the addition of 10% purple sweet potato decreased the taste and texture of sausage. Correlation coefficients between overall acceptability, texture, appearance, color, taste, and flavor were 0.901, 0.895, 0.877, 0.844, and 0.688, respectively. Therefore, proper content of purple sweet potato powder and purple sweet potato pigment were determined to be 5% and 0.2%, respectively, for the substitution of sodium nitrite.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.3
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• pp.386-395
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• 2016

To develop a functional fermentation food from Rubus coreanus Miquel (Bokbunja) and chlorella mixtures, optimal lactic acid fermentation conditions were established, and quality properties based on physicochemical evaluation such as chemical compositions, free sugars, organic acids, and antibacterial activities were investigated. Regarding optimal fermentation strain selection, formation of lactic acid was best in Lactobacillus plantarum among the experimental strains (10 kinds), and the optimal fermentation temperature was $37^{\circ}C$. In addition, overall acceptability in the sensory evaluation was highest in the 5% chlorella mixture sample. Therefore, quality properties of the prepared sample under the established optimal fermentation conditions were investigated. Moisture, total sugar (dry basis), crude fiber (dry basis), and pH of fermented Rubus coreanus Miquel juice (RCM) with 5% chlorella mixture (RCM-C5) were reduced by 4.90%, 14.15%, and 0.32%, respectively, as compared with non-fermented RCM. Meanwhile, crude protein, crude fat, and crude ash (dry basis) of RCM-C5 were elevated by 13.75%, 0.18%, and 0.73%, respectively, as compared with RCM. The yellowness (b value) of color values was greater in RCM-C5 compared to RCM. The free sugar and organic acid contents of RCM-C5 were elevated by 0.97% and 616.30 mg%, respectively, as compared with RCM. In addition, the gram positive bacterium Staphylococcus aureus was elevated by 5.83% while gram negative bacteria Escherichia coli and Salmonella Typhimurium were elevated by 2.94% and 4.67%, respectively, as compared with RCM. In conclusion, the quality properties of RCM and chlorella lactic acid fermentation mixtures were improved compared with the general RCM product. Consequently, it is possible to apply fermented RCM as a functional fermentation food.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.3
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• pp.352-359
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• 2016

White bread added with brown rice fiber was prepared by addition of 0.005, 0.010, 0.015, and 0.020% hemicellulase. Effects on product quality and sensory evaluation were examined. There were no significant differences in pH of dough before the 1st fermentation among the experiments. Dough made by addition of hemicellulase had a significantly higher pH after the 1st fermentation compared to the control group, whereas pH of bread had reverse effects. Fermentation power of dough expansion increased as incubation time increased. Addition of hemicellulase to samples significantly increased specific volume, baking loss, and water activity compared to the control sample. Moisture content was the lowest upon addition of 0.020% hemicellulase. For color, lightness was the highest in the control bread samples, greenness of the 0.015% addition sample was the lowest and yellowness of the 0.005% addition sample was the highest. For textural characteristics, hardness, gumminess, and chewiness were maximum in the control group. Cohesiveness and springiness were not significantly different between the samples. In the sensory evaluation, color, flavor, bran flavor, bitterness, astringency, and coarseness were not significantly different among the samples. Softness and overall acceptability were highest at the 0.020% addition level but lowest at the 0.010% level. The results indicate that addition of 0.020% hemicellulase to brown rice fiber white bread is optimal for quality and provides products with reasonably high overall acceptability.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.9
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• pp.1140-1147
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• 2007

A recipe for diet kimchi containing 20% of sea tangle to Korean cabbage kimchi (SK) was developed for weight reduction purpose. The fermentation process of SK showed typical Lactobacillus sp. growth pattern like other kimchis. The effects of SK on weight reduction was studied in high fat diet (HFD) fed rats (n=40). Diet groups used for the animal study were HFD, HFD supplemented either with Korean cabbage kimchi used as experimental control (HCK), or with SK (HSK), or with J-kimchi (JK) which was purchased at market (FJK). The effect of kimchi on preventing obesity in rat fed HFD was found to be obvious by means of reducing visceral fat contents and improving serum lipid profiles through enhancing the lipid excretion in the feces (p<0.05). Leptin concentration of rat was significantly decreased by kimchi consumption (p<0.05). This result can be interpreted that adipocytes in these animals were fewer than that of HFD group. The plasma bililubin concentration was lower in kimchi group than HFD, meaning that returning bile from ileum to the liver was reduced. When the observe beneficial effects of kimchi on preventing obesity were compared among kimchi groups, SK only reduced the relative visceral fat contents significantly than other kimchi groups (p<0.05). Besides this, other parameters such as plasma lipid profiles, feces lipids, leptin, and bililubin concentration were not significantly different, even though the most beneficial effect on these parameters was observed from SK. In conclusion, long term consumption of SK seems to have a beneficial effect on the prevention of obesity through enhancing the excretion of lipids in the feces. The dietary fiber content of SK was increased by 7% compared to CK when 20% of sea tangle was added.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.12
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• pp.1622-1627
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• 2007

This study was undertaken to evaluate the effects of chlorine dioxide on reducing E. coli O157:H7 and L. monocytogenes on broccoli served in foodservice institutions. Broccoli samples inoculated with $10^6$ CFU/mL of E. coli O157:H7 and L. monocytogenes were treated with chlorine dioxide. Treatments with 5, 10, and 20 ppm for 1, 5, and 10 min were not sufficient in controlling E. coli O157:H7 on broccoli. L. monocytogenes were effectively reduced by $2.19{\sim}2.48log\;CFU/g\;and\;3.31{\sim}3.87log\;CFU/g$ with 10 and 20 ppm chlorine dioxide for 1, 5, and 10 min treatment, respectively, compared with the control. E. coli O157:H7 and L. monocytogenes population were significantly negatively correlated with concentration and treatment time of chlorine dioxide. These results show that the use of chlorine dioxide was effective in sanitizing L. monocytogenes on broccoli and the level of concentration was more associated with populations of E. coli O157:H7 and L. monocytogenes than treatment time of chlorine dioxide on broccoli.

• Food Engineering Progress
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• v.13 no.2
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• pp.117-121
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• 2009

Detection of spoilage odors from beef during storage was investigated using sensory evaluation with R-index, and microbial assay for Pseudomonas. Beef samples were tested to measure the flavor changes, which were converted to R-index, and the Pseudomonas levels during storage. There was a steep rise in R-index until 36 hr after storage at 25$^{\circ}C$, and then a gentle rise from 48 hr, whereas, there was a steady rise in R-index in the whole range of storage at 5$^{\circ}C$. Detection time of spoilage odors according to R-index was statistically analyzed at $\alpha$=5% to be at 30.92${\pm}$3.47 hr and 169.80${\pm}$11.27 hr for 25 and 5$^{\circ}C$ storage, respectively, and analyzed at $\alpha$=1% to be 34.80${\pm}$4.01 and 176.41${\pm}$9.89 hr for 25 and 5$^{\circ}C$ storage, respectively. At the detection times of spoilage odors, the Pseudomonas levels were found to be almost the same, but less than 6-7 log CFU/g generally known as a standard level at occurrence of spoilage odors in beef. This indicated that some other factors than the Pseudomonas reactions could be associated with generation of spoilage odors.

• Journal of agriculture & life science
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• v.45 no.6
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• pp.95-108
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• 2011

The food quality characterization and safety Japanese flying fish roe (JFF-R), capelin roe (C-R), Pacific herring roe (PH-R) were investigated. The size of JFF-R was 1.48-1.93 mm, which was longer than those of C-R and PH-R. The moisture content of JFF-R imported from Peru (JFF-R-P) was 70.3%, which was higher than that of JFF-R imported from China (JFF-R-C) (67.4%), while was lower than that of JFF-R imported from Indonesia (JFF-R-I) (83.3%). However, the salinity of JFF-R-P was 13.6%, which was lower than that of JFF-R-C, while was higher that of JFF-R-I (1.8%). The moisture contents and salinities of the other fish roes were 80.4% and 3.2%, respectively, for capalin roe, and 65.4% and 20.0%, respectively, for Pacific herring roe. According to the results of pH, volatile basic nitrogen content, heavy metal content, viable cell count and coliform group, the fish roes could be used as sanitary sources for preparation of seasoned JFF-R. The major fatty acids of fish roes were 16:0 (27.8-30.5%), 18:1n-9 (7.2-8.0%), 20:5n-3 (5.6-8.2%) and 22:6n-3 (22.0-25.6%) in JFF-R, and 16:1n-7 (6.7-9.3%) as well as these fatty acids in C-R and PH-R. Total amino acid contents of fish roes ranged from 9.44 g/100 g to 10.39 g/100 g and their major amino acids were aspartic acid, glutamic acid, leucine and lysine. The mineral content of JFF-R were higher than those of the other fish roes expected for zinc of JFF-R-I. According to the results of sensory evaluation, the color and texture of JFF-R-P were superior to those of the other fish roes. No difference was, however, found in flavor, among JFF-R-P and the other fish roes.