• Korean Journal of Food Science and Technology
• /
• v.38 no.4
• /
• pp.513-520
• /
• 2006

Spray-dried (SD) and freeze-dried (FD) takju powders were stored at 5, 15 and $25^{\circ}C$, and various quality characteristics such as moisture, amino nitrogen, color value, total viable cell count, total sugar, reducing sugar organic acid, and flavor compounds were measured for 50 days at 10-day intervals. After 50 days of storage, the moisture content was increased from an initial 6.64% to 7.24-7.38% in the SD powder, and from an initial 4.86 to 5.43-5.61% in the FD powder. pH, total acid content and total viable cell counts were slightly increased. Organic acid content was decreased in the SD powder from an initial 3,949.9 mg% to 805.9-922.3 mg%, and in the FD powder from an initial 5,171.5 mg% to 3,646.0-4,110.2 mg%. Amino nitrogen content was increased in the SD powder from an initial 1.2% to 1.9-2.2% and in the FD powder from an initial 1.9% to 2.2-2.5%. Total sugar and reducing sugar contents were increased in the SD powder from an initial 17.2% and 4.0% to 25.9-27.3% and 5.8-6.9%, and in the FD powder from an initial 19.1% and 5.2% to 29.2-30.2% and 8.3-8.8%, respectively. With increasing storage time, L and b values in the SD powder increased slowly, while L value in the FD powder tended to decrease and b value tended to increase. About 20 major volatile flavor components were identified in the SD and FD powders by GC-MS and all such component levels were decreased with increasing storage time.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.8
• /
• pp.1246-1250
• /
• 2005

This study was carried out to analyze the components of the stem of bush clover, Lespedeza bicolor to obtain basic data on the studies of the physiological function and a possibility of utilizing L. bicolor. General components of L. bicolor were 82.35$\%$ carbohydrate, 13.38$\%$ moisture, 2.80$\%$ crude protein, 0.86$\%$ crude ash and 0.61$\%$ crude fat. The content of reducing sugar was 147.58 mg/100 g. The total amount of free sugar was 52.4 mg/100 g that was composed of 31.0 mg/100 g fructose, 16.7 mg/100 g glucose and 4.7 mg/100 g sucrose. In the results of mineral analysis, the content of Ca was the highest (472.97 mg/100 g) and followed by 206.70mg/100 g of K. The total amount of hydrolyzed amino acid was 148.95 mg/100 g that consist of 31.74 mg/100g of essential amino acid and 117.24 mg/100 g of non-essential amino acid. Total free amino acids were contained 106.39 mg/100 g that was composed of 8.41 mg/100 g essential amino acids and 97.98 mg/100 g the non-essential, and proline (62.92 mg/100 g) was the highest that account for 59.8$\%$ of total free amino acids. Total content of amino acid derivatives was 30.01 mg/100g and that of $\gamma$ -aminoisobutyric acid was the highest as 12.57 mg/100 g among them.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.30 no.6
• /
• pp.1038-1040
• /
• 2001

This study was conducted to investigate the constituents of pumpkin, to develop of health food using pumpkin. Crude protein contents of skin (19.82%) and fiber (16.43%) were higher than that of flesh. Crude lipids contents of skin (2.84% ) was higher than those of flesh and fiber. Major free sugars in pumpkin were sucrose, fructose and glucose. Total sugar contents in the flesh was higher than that of fiber. This tendency was opposite to reducing sugar contents. Also, free sugar contents in pumpkin were flesh (30.19 mg/100 g), fiber (22.99 mg/100 g) and skin (15.67 mg/100 g), respectively. The total Phenol and carotenoid contents in 100 g of fiber revealed 379.8$\pm$9.76 mg and 43.71$\pm$1.46 mg, corresponding to 47% and 62% of the total phenol and carotenoid contents of pumpkin. Total flavonoid content in 100 g of skin revealed 81.5$\pm$3.56 mg.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.42 no.5
• /
• pp.736-742
• /
• 2013

The physiochemical properties of commercial fruit vinegars were compared according to fermentation methods. Type A vinegars were synthesized through acetic acid fermentation while Type B vinegars were produced using both alcohol and acetic acid fermentation serially. There were differences from using these fermentation methods; Type A vinegars had a lower pH and slightly higher total acidity than Type B vinegars. The content of total sugar and reducing sugar were relatively higher in Type B vinegars, which showed a higher content of the free sugars (fructose, glucose, sucrose, and maltose). The intensity of brown color and Hunter's a and b values were also high in Type B vinegars. In contrast, the content of organic acids was higher in Type A vinegars, which were mainly composed of acetic, tartaric, malic, and succinic acid. We were also able to estimate the fruit juice content of vinegars through its content of organic acids. Type B vinegars contained a higher total phenolics and flavonoids content than Type A vinegars, and showed a higher DPPH radical scavenging activity.

• Food Science and Preservation
• /
• v.15 no.5
• /
• pp.699-705
• /
• 2008

This study compared amino acids and effective components of Viola mandshurica produced in Korea with those of Chinese plants, as part of a study on nutritional andfunctional materials, to aid in the development of a valuable food. The contents of reducing sugar, free sugar, polyphenols, and soluble protein in the flowers of V. mandshurica were higher than in other fractions, being 10,485.11 mg%, 118.85 mg%, 1,259.26 mg%, and 23.67 mg%, respectively. Total flavonoid content of Chinese leaves was the highest at 2,370.75 mg%, followed by 1,844.43 mg% in Korean leaves. Free amino acids were highest in Korean leaves (5,345.21 mg%), followed by roots (4,692.24 mg%), flowers (3,807.87 mg%), and leaves of China plants (3,613.81 mg%). Arginine accounted for 55% of free amino acids in the roots, and all plant fractions contained more valine, aspartic acid, glutamic acid, alanine, and arginine, than other amino acids. The total content of amino acid derivatives was the highest (9,058.80 mg%) in Korean leaves. Especially, $\alpha$-aminoadipic acid constituted over 50% of total amino acid derivatives in all plant parts of V. mandshurica. When mineral contents were analyzed, leaves grown in China showed the highest content of 5,917.57 mg%, and the contents of K, Ca, and Mg were much greater than those of other minerals, together comprising over 95% of total mineral content in leaves and flowers from Korea.

• Korean Journal of Plant Resources
• /
• v.29 no.5
• /
• pp.539-546
• /
• 2016

The aim of this study was to analyze antioxidant activity, total phenolics, and vitamin C content in unripe and ripe jujube cultivar and to investigate correlation between antioxidant and chemical constituents including total phenolics and vitamin C. The antioxidant activity was measured by the DPPH radical scavenging activity, ABTS radical scavenging activity, and reducing power. Although, the weight, diameter and soluble solids of Zyziphus jujuba fruit were increased with the progress of ripening, antioxidant activity and total phenolics were decrease during ripening. The highest free-radical scavenging activity (at 2.5 ㎎/㎖) and reducing power (at 1 ㎎/㎖) in fruit were 81.75% (Bokjo, unripe) and 0.80 (Mudeung, unripe), respectively. The highest total phenolic content in unripe fruit of Mudeung was 62.50 ㎍/g. A linear correlation (r=0.911) was shown between DPPH radical scavenging activity and total phenolic content.

• Microbiology and Biotechnology Letters
• /
• v.44 no.1
• /
• pp.48-54
• /
• 2016

In this study, biosugar production by the red-algae Eucheuma cottonii was investigated using dilute sulfuric acid-catalyzed hydrolysis and data analysis by response surface methodology. This approach yielded 25.8 g/l total reducing sugar under the conditions of $160.1^{\circ}C$, 1% (v/v) sulfuric acid, and 13.1 min. The sugar concentration showed a linear inverse correlation with the combined severity factor (CSF) of the reaction conditions. CSF was calculated as $log(t{\cdot}e{xp}[(T_H-T_R)/14.75])-pH$, where t is the coupling reaction time, $T_H$ is the target temperature, and $T_R$ is the reference temperature ($100^{\circ}C$). In addition, levulinic acid production showed a linear positive correlation with CSF. E. cottonii may represent a useful feedstock for sugar production in the field of bioenergy.

• Applied Biological Chemistry
• /
• v.29 no.4
• /
• pp.392-398
• /
• 1986

This study was conducted to find out the variation modes of the absorbtion contents of N, P and K and the contents of decursin, decursinol and sugar in Angelica gigas Nakai at different growth stages. The results of field study were as follows. The dried weights of root and shoot was increased by the application of nitrogen and potassium fertilizers during the growing seasons. But, the effect of phosphorus application was observed only the increasing of the dried weight of shoot. During the growing seasons, the contents of nitrogen and phosphorus in root was decreased, but in shoot was increased. The potassium contents of root was increased and that of shoot was decreased. The decursin and total sugar contents of root were continually increased, and the decursinol and reducing sugar contents were increased until the middle growth stage and after that were decreased.

• Journal of the Korean Society of Food Culture
• /
• v.6 no.1
• /
• pp.61-69
• /
• 1991

Brewing method and quality of 10 sample of traditional Dungge-Jang in Kyungsang-Do area were investigated. In order to improve the taste of Dungge-Jang, some amount of boiled bean was added in the Dungge-Jang at early stage of fermentation. The level of amino nitrogen turned out to be low while that of water soluble protein and salt soluble protein was high. Glutamic acid, aspartic acid and proline were the major amino acid in water and salt soluble protein in traditional Dungge-Jang in Kyungsang-Do area. The content of total sugar and free reducing sugar were found to be considerably high, and among the free sugar, glucose was the highest$(2.16{\sim}4.02\;mg/ml)$, followed by maltose and maltotriose. Activities of acid protease and liquefying amylase were $0.13{\sim}1.36$ unit per milliliter and $10.18{\sim}15.19D^{40o}_{30}$ respectively. Result of sensory evaluation showed that the good Dungge-Jang turned out to have well harmonized taste of flavor, sweetness and sourness while the color looked slightly dark and yellow.

• Journal of the Korean Society of Food Culture
• /
• v.17 no.3
• /
• pp.267-274
• /
• 2002

The quality characteristics of traditional Kyungsangdo Myungtae (Alaska pollack) sikhae including optimal composition of the product were investigated. In the sensory evaluation, the Myungtae sikhae made from Gampo accepted to be best for traditional Kyungsangdo Myungtae sikhae and it is called standard sikhae. The standard sikhae was prepared as follows: dried-Myungtae 200g, cooked rice 230g, red pepper 92g, garlic 112g, ginger 100g, radish 1.6kg, salt 20g, and malt meal 65g. The Myungtae sikhae made from Gampo showed higher values in total sugar, free reducing sugar, and nitrogen compounds than the Myungtae sikhae made from another locations. The sugar of standard sikhae consisted of four kinds including glucose. And, the contents of free amino acid was increased in the order of glutamic acid, alanine, and methionine. The composition of free amino acid in Myungtae sikhae contained 17 kinds, and the contents was increased in order of glutamic acid, aspartic acid, and proline. The organic acid of standard Myungtae sikhae consisted of 7 kinds including lactic acid during fermentation. The contents of citric acid, succinic acid, and lactic acid gradually increased during fermentation, and especially, increasing of lactic acid remarkably increased than the different organic acid.