• Food Science and Preservation
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• v.17 no.1
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• pp.23-29
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• 2010

The effects of vinegar, alcohol, and vitamin C on the color, microorganism count, volatile flavor components, free sugar level, free amino acid concentration, and free fatty acid level of minced ginger were investigated during storage for 17 weeks at $10^{\circ}C,\;20^{\circ}C\;or\;30^{\circ}C$. Bacterial levels remained unchanged during storage and mold was not initially detected. Yeast levels in minced ginger were $5{\times}10^1$ CFU/g initially, and yeast was not detected after 2 weeks. The color values increased during storage at high temperature. The volatile flavor component levels decreased during high-temperature storage. The free sugars of minced ginger were glucose, sucrose, and fructose. Sugar levels did not vary greatly with storage temperature. Free amino acid content decreased during high-temperature storage, and glutamine, valine, alanine, asparagine, tyrosine, and leucine were detected. Free fatty acid content increased during storage and the ratio of unsaturated to saturated fatty acids was 3:7.

• Food Science of Animal Resources
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• v.29 no.1
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• pp.132-139
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• 2009

The objective of this study was to investigate the most effective analysis methods for palatability grading of Hanwoo beef by comparing the results of discriminant analysis with sensory data. The sensory data were obtained from sensory testing by 1,300 consumers evaluated tenderness, juiciness, flavor-likeness and overall acceptability of Hanwoo beef samples prepared by boiling, roasting and grilling cooking methods. For the discriminant analysis with one factor, overall acceptability, the linear discriminant functions and the non-parametric discriminant function with the Gaussian kernel were estimated. The linear discriminant functions were simple and easy to understand while the non-parametric discriminant functions were not explicit and had the problem of selection of kernel function and bandwidth. With the three palatability factors such as tenderness, juiciness and flavor-likeness, the canonical discriminant analysis was used and the ability of classification was calculated with the accurate classification rate and the error rate. The canonical discriminant analysis did not need the specific distributional assumptions and only used the principal component and canonical correlation. Also, it contained the function of 3 factors (tenderness, juiciness and flavor-likeness) and accurate classification rate was similar with the other discriminant methods. Therefore, the canonical discriminant analysis was the most proper method to analyze the palatability grading of Hanwoo beef.

• Applied Biological Chemistry
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• v.40 no.6
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• pp.472-477
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• 1997

The effects of roasting Cassia tora L. were investigated for proximate composition, color, volatile flavor profile, microbial growth and alcohol fermentation. While moisture, protein and fat contents decreased with increasing roasting temperature, fiber and ash contents increased. The L, a and b values of Cassia tora L. extracts decreased with increasing temperature, and only a small difference in total color difference$({\Delta}E)$ was observed. A little difference in major flavor components between raw and roasted treatment was found during roasting. Furfuryl alcohol, a major component of coffee flavor, was separated from Cassia tora L. extracts extracted with ethyl ether. The yeast growth was the highest on the water-extract of Cassia tora L. roasted at $160^{\circ}C$. With increased levels of water-extract at $160^{\circ}C$, S. cerevisiae grew rapidly for 24 hr incubation and the growth rate was higher than the unroasted control group. The growth rate of Bacillus subtilis was the highest in a treatment of 0.5% concentration. Little differences in ${\alpha}-amylase$ produced from Bacillus subtilis were observed among the treatment groups. The total alcohol content increased with increasing roasting temperature during alcohol fermentation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.7
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• pp.822-832
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• 2017

This study analyzed contents of organic acids, free sugars, and volatile flavor compounds by type of Jerusalem artichoke (Helianthus tuberosus L.). Organic acids in dried Jerusalem artichoke were mainly composed of malic acid, citric acid, and succinic acid. Sucrose, fructose, and glucose were the major sugar components of dried Jerusalem artichoke. Free sugars were more abundant in the white colored sample than in the purple colored sample. In contrast, purple colored sample contained more organic acids than the white colored one. Volatile compounds in Jerusalem artichoke were investigated using the solid-phase micro-extraction method of gas chromatography/mass spectrometry. A total of 117 volatile compounds were identified in Jerusalem artichoke, and chemical classification was as follows: 5 acids, 13 alcohols, 19 aldehydes, 12 hydrocarbons, 15 ketones, 8 miscellaneous, 27 pyrazines, and 18 terpenes in all samples. Terpene was the most abundant in Jerusalem artichoke, and ${\beta}$-bisabolene was the main component in terpenes. The second most common compound was aldehyde, and hexanal was the highest. Pyrazines were the most abundant in the roasted samples, and 2,5-dimethyl-3-ethylpyrazine was present at the highest level, followed by 2,5-dimethylpyrazine. Compared with purple samples, main compounds contained in white samples were aldehydes and hydrocarbons, whereas the major compounds in purple samples were terpenes and alcohols.

• Food Science and Preservation
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• v.17 no.6
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• pp.770-776
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• 2010

Sarcodon aspratus (Berk.) S. Ito is a wild mushroom commonly consumed in Korea due to its beneficial effects on health. However, only limited information on the volatile and nonvolatile constituents of S. aspratus is available. In the present study, the total concentration of mushroom soluble sugars, including glucose, trehalose, sucrose, and xylose, was found to be 202.5 mg/kg. The total contents of free and essential amino acids were 2,592.1 mg/kg and 1,249.5 mg/kg, respectively; arginine, lysine, methionine, and valine were the major amino acids present. The contents of total 5'-nucleotides and flavor 5'-nucleotides in S. aspratus were 2,510.7 mg/kg and 773.4 mg/kg, respectively. The volatile components of S. aspratus were collected by simultaneous distillation-extraction (SDE) and analyzed by gas chromatography-massspectrometry (GC-MS). A total of 27 volatile compounds were isolated and identified. The most abundant was l-octen-3-ol, which accounted for more than 68% of total volatiles; other important compounds were 2-octen-1-ol, 1-octen-3-one, and 2-octenol. Our results provide preliminary data for the development of S. aspratus as a food material.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.11
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• pp.1638-1648
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• 2016

This study was conducted to analyze the quality characteristics of kimchi in terms of garlic content (0~4.5%). Kimchi was made at $4^{\circ}C$ for 8 weeks, and pH, acidity, organic acid content, free sugar content, microbial counts, flavor pattern, and sensory characteristics were measured. The results show that kimchi containing garlic had a higher pH and lower acidity during fermentation than control kimchi without garlic. Principal component analysis enabled differentiation of the flavor pattern of kimchi according to fermentation period and garlic content. Addition of garlic to kimchi significantly decreased the numbers of total bacteria and lactic acid bacteria for 2 weeks after production. The numbers of total bacteria and lactic acid bacteria increased rapidly up to 2 weeks during fermentation and thereafter decreased gradually. Coliform counts were higher in the control than in kimchi containing garlic, whereas there was no detection after 4 weeks. Yeast and mold counts decreased significantly with increasing garlic content during the initial fermentation stage. Counts could not be detected in kimchi containing garlic. After 4 weeks, counts could not be detected in kimchi without garlic. Among kimchi with different garlic contents, fermentation was slower in kimchi with high garlic content; scores for off-odor and off-note taste were lower as well.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.507-514
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• 2010

This study was performed to reduce unpleasant taste and flavor of $Gastrodia$ $elata$ Blume as well as to improve utilization as functional food materials using fermentation. The component, antioxidant activity, and taste test were compared between fresh and fermented $Gastrodia$ $elata$ Blume powder (FGP). FGP contained higher level of total fat, protein, mineral, and fiber than raw material. The pH of FGP was higher compared to raw $Gastrodia$ $elata$ Blume powder (RGP), and antioxidant activity was as high as vitamin C regardless material status (raw vs. fermented). This result indicated that its activity was not decreased by fermentation. Dispersiveness and solubility of $Gastrodia$ $elata$ Blume powder was the best in 60-70 mesh. For sensory evaluation, FGP or RGP was mixed with either orange juice or yoghurt. The results showed that overall preference, taste, flavor, texture, and color were better in fermented $Gastrodia$ $elata$ Blume drinks than in raw ones. It is plausible that unpleasant taste and flavor of $Gastrodia$ $elata$ Blume was declined by fermentation. Thus, fermentation can be easily applied to eliminate unpleasant smell in $Gastrodia$ $elata$ Blume, and FGP can be mixed with other beverages to produce healthy food and drinks.

• Korean Journal of Food Science and Technology
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• v.37 no.3
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• pp.431-437
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• 2005

Overall experiments were planned by central composite design, and results were analyzed by response surface methodology (RSM) to determine effects of three independent variables, temperature ($X_{1}$), extraction time ($X_{3}$), and pressure ($X_{3}$), on yield of sesame oil extract (Y). Regression equation model optimized by response surface analysis was: Y (sesame oil) = $-3.89+0.07X_{1}+0.03X_{2}+0.0006X_{3}-0.0007X_{1}^{2}-0.0002X_{2}X_{1}-0.00008X_{2}^{2}+0.000004X_{3}X_{1}+0.0000009X_{3}X_{2}-0.00000009X_{3}^{2}$. According to RSM analysis, optimum extracting conditions of temperature, time, and pressure were $45.89^{\circ}C$, 131.89 min, and 34228.41 kPa, respectively, and statistical maximum yield of sesame oil was 96.27%. Fatty acid composition of sesame oil showed sesame oil extracted by Supereritical Fluid $CO_{2}$ contained lower levels of palmitic, stcaric, and oleic acids and higher levels or palmitoleic and linoleic acids than commercial sesame oil. Commercial and extracted sesame oils were analyzed by electronic nose composed of 12 different metal oxide sensors. Obtained data were interpreted by statistical method of MANOVA. Sensitivities of sensors from electronic nose were analysed by principal component analysis. Proportion of first principal component was 99.92%. All sesame oils showed different odors (p < 0.05).

• Korean Journal of Food Science and Technology
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• v.30 no.3
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• pp.717-720
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• 1998

Some physico-chemical components of Chinese water chestnut were analysed to provide fundamental data for water chestnut processing and products development. The contents of moisture, crude protein, crude lipid, crude ash, crude fiber and carbohydrate of Chinese water chestnut were 79.40%, 1.74%, 0.06%, 1.10%, 0.60% and 17.71% respectively. Free sugars identified in Chinese water chestnut juice were sucrose 8.58%, glucose 1.64% and fructose 1.58% as major component and maltose as trace component. The proportion of major free sugars to total soluble solid content of juice was about 66.0%. Potassium content in Chinese water chestnut was 408.57 mg% as major mineral, iron and manganese content were 0.21 mg% and 0.08 mg% as minor mineral. $Vitamin\;B_1$ and C content were $31.2\;{\mu}g/100\;g$ and trace respectively. Organoleptic properties of Chinese water chestnut were fresh fruit odor and sweet taste as main flavor. Though water chestnut was boiled for 20 min, crunchy texture of flesh was almost maintained.

• Korean Journal of Food Science and Technology
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• v.30 no.3
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• pp.535-541
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• 1998

The soluble solid of red pepper extracted by water was evaluated with descriptive analysis by 10 trained sensory subjects. In the result of the sensory evaluation, the character notes on the flavor of soluble solid were expressed as pungency, sweet, fresh sour, bitter, alcoholic, meaty, chalkiness and astringent. The score of redness was the highest at $4^{\circ}C$ and decreased after 2 hr at $90^{\circ}C$ and the score of sensory pungency was more than 50 and was especially higher at $40^{\circ}C\;and\;90^{\circ}C$. Principal component analysis of the mean ratings showed that kochoojang (fermented red pepper paste) and chigae (meat and vegetable stew) differed from kimchi (unfermented kimchi) and that they had unique sensory attributes. The first two principal components could be explained by 51% of all the components and the taste of soluble solid at $40^{\circ}C$ was highly correlated with sensory attributes such as meaty, fresh sour and sweet and that at $4^{\circ}C$ was chiefly correlated with color components and the taste of soluble solid at $60^{\circ}C$ was showed close relation to astringent, alcoholic and pungency.