• Korean Journal of Food Science and Technology
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• v.30 no.3
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• pp.608-614
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• 1998

In order to establish the scientific foundations for the production of Korean traditional kanjang (soy sauce) in a semi-pilot scale, meju preparation and kanjang mashing methods were investigated. Two types of meju, one that was prepared by conventional method (CM-meju) and the other that prepared by modified conventional method (MCM-meju), were made and compared their characteristics. The former made of cooked and crushed soybean with a brick shape was fermented at $15{\sim}20^{\circ}C\;and\;40{\sim}50%$ relative humidity (RH) for 30 days in koji room and the latter was fermented at $25{\sim}30^{\circ}C\;and\;80{\sim}90%$ RH seemingly being optimum for the growth of meju-organisms for the same period. The quality of MCM-meju as a raw material for the kanjang preparation was considered to be superior to that of CM-meju as the higher soluble nitrogen and total free amino acids content, the major factor for the evaluation of the quality of meju, were found in the former although the higher total nitrogen content and lower % weight loss were observed in the latter during meju preparation process. The quality of MCM-kanjang with higher total nitrogen, free amino acids, free sugars and the lower residual nitrogen content in cake after separation of kanjang was also found to be superior to that of CM-kanjang in sensory evaluation results.

• Food Science and Preservation
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• v.24 no.6
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• pp.849-856
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• 2017

In this study, we investigated the variation in free sugars, organic acids, amino acids, antioxidant activity and anti-inflammatory effect of Solanum nigrum Linne fruits according to harvest time. Four kinds of free sugars (fructose, glucose, sucrose, maltose) were detected in S. nigrum fruit, and the free sugar contents varied significantly with harvest time. Organic acid content of S. nigrum fruit showed the highest in malic acid and acetic acid, and the highest content of total organic acids was found in S. nigrum fruit harvested on October $18^{th}$ and October $25^{th}$. For the total polyphenol content, S. nigrum fruit harvested on October $18^{th}$ was the highest. The strongest DPPH and ABTS radical scavenging activity was showed in S. nigrum fruit harvested on October $11^{th}$ and October $18^{th}$. The anti-inflammatory activity and antioxidant effects were the highest in the ethanol extract from S. nigrum fruit collected on October $18^{th}$ and October $11^{th}$. Thus, it seems the best to harvest of S. nigrum fruit harvested on October $11^{th}$ and October $18^{th}$.

• Food Science and Preservation
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• v.24 no.6
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• pp.865-870
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• 2017

Yogurt is produced by fermentation of milk using bacteria known as "yogurt cultures". Most of these bacteria are probiotics such as Lactobacillus delbrueckii subsp. bulgaricus, Lb. rhamnosus, Streptococcus thermophilus, and Bifidobacterium. The domestic fermented milk market is increasing, and about 30 companies are producing yogurt. The purpose of this study was to analyze the quality characteristics of domestic commercial liquid yogurt. Total 30types of commercial yogurts were sampled and their physicochemicial properties, including pH, sugar content, acidity, viscosity, and microbial characteristics of lactic acid bacteria counts, were measured. Commercial liquid type yogurt showed a pH of 4.5, sugar content of 7.4-21.2%, total acid content of 0.4-0.9%, and viscosity of 0.1-250 cP. In terms of microbial populations, lactic acid bacteria counts were 7.2-11.3 log CFU/mL and anaerobic lactic acid bacteria counts were 8.0-11.5 log CFU/mL. The quality characteristics differed depending on the constituents of the sample and the microorganisms used. These results are related to the quality characteristics of yogurts and are useful for identifying new trends in the domestic fermented milk industry.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.1
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• pp.41-50
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• 2012

The study was carried out to analyze the relationship between analysis of antioxidant activity and the level of functional components according to particle size of corn silk. Particle size was classified into 5 groups. By particle size distribution and color difference, the total phenol content and DPPH radical scavenging activity were observed. The particle sizes of corn silk were $199.17{\mu}m$, $178.27{\mu}m$, $85.48{\mu}m$, $27.4{\mu}m$ and $20.97{\mu}m$, respectively. The lightness of colored pigments was increased when the particle size was decreased. The contents of free sugar (fructose, glucose, galactose, sucrose, and maltose) of corn silk were analyzed using a HPLC. The total phenol contents by the particle sizes of corn silk were 2.01 mg/g, 2.02 mg/g, 2.06 mg/g, 2.26 mg/g and 2.26 mg/g, respectively. DPPH radical scavenging activities of samples were 21.00%, 21.75%, 22.90%, 24.35% and 23.67%, respectively. Antioxidative activities of Trolox and Fe(II) in corn silk were measured by ferric reducing antioxidant power (FRAP) assay and Trolox equivalent antioxidant capacity (TEAC) assay. TEAC values of samples were $2.36{\mu}mol$ TE / g dw, $2.81{\mu}mol$ TE / g dw, $3.20{\mu}mol$ TE / g dw, $3.36{\mu}mol$ TE / g dw, and $3.44{\mu}mol$ TE / g dw, respectively. FRAP values of samples were $11.67{\mu}mol$ Fe(II) / g dw, $12.80{\mu}mol$ Fe(II) / g dw, $13.43{\mu}mol$ Fe(II) / g dw, $13.85{\mu}mol$ Fe(II) / g dw and $15.95{\mu}mol$ Fe(II) / g dw, respectively. Total phenolic content and antioxidantive activities based on FRAP assay and TEAC assay were increased with decreasing particle size. In addition, DPPH radical scavenging activity was also increased. A significant correlation was also noted between DPPH radical scavenging activities and the content of phenolic compounds.

• Horticultural Science & Technology
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• v.29 no.1
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• pp.1-9
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• 2011

This study was performed to investigate the role of plant growth substances on the bulbing of cold type of garlic (Allium sativum L. cv. Uiseongmaneul) during long and short day conditions. The change in endogenous plant hormones such as abscisic acid (ABA), jasmonic acid (JA) and sugar contents in leaf blade and sheath was examined during the growth stage from bulb differentiation (starting at April 16) to bulbing (April 24 to May 18) in cold type of garlic. In the long day condition, ABA contents were higher than short day condition and ABA contents of leaf sheath were higher than leaf blade. ABA contents of growth stage in garlic were not changed during growth stage from April 16 to May 2, however it rapidly increased during bulbing (May 2 to May 18). On the other hand, endogenous JA contents in short day condition did not change in long day condition, it increased from April 16 to May 2. JA contents in the leaf sheath (33.85-62.04 $ng{\cdot}g^{-1}$ DW) were higher than leaf blade (15.39-30.04 $ng{\cdot}g^{-1}$ DW). These results showed that garlic bulb differentiation and bulbing was induced by JA in leaf sheath. In long day condition, total sugar contents in the leaf blade were increased from bulb differentiation (April 16) to bulbing (May 4) and it was decreased during bulbing (May 4 to May 18) while the total sugar content in leaf sheath were gradually increased from bulb differentiation (April 16) to bulbing (May 18). In conclusion, our results showed that there is a significant correlation between the bulb development of garlic and hormonal content in the leaf sheath.

• Food Science and Preservation
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• v.30 no.5
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• pp.833-846
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• 2023

Onions are essential vegetables for Koreans' diet and have various physiological activities. However, problems arise every year due to the imbalance between production and demand. Therefore, in this study, nutritional and functional components, and antioxidant activity were analyzed for each growth period in order to utilize onions at the disposal period. Whole onions harvested before June showed higher values of general ingredients, inorganic ingredients, organic acids, spiraeoside, quercetin, total chlorophyll, and antioxidant activity than bulbs harvested in June. On the other hand, the free sugar content was higher in the bulb of the harvest season in June than in whole onions. The total thiosulfinate content was similar to that of whole onions and bulbs in the early stages of growth. In addition, as a result of comparing the flavonoid compound and antioxidant activity of each onion variety, whole onions harvested at 25 weeks were higher in content than onion bulbs harvested in June. In conclusion, onions before the harvest season in June had excellent utilization value as food. Harvesting before 21 weeks is desirable for growing onions with excellent nutritional value, while harvesting after 23 weeks is recommended for excellent functional components and antioxidant activity in onions.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.6
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• pp.1049-1057
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• 2015

This study investigated the physicochemical properties of Dioscorea batatas for improvement of biological activities during a three-step steaming process, steaming $120^{\circ}C$ for 30 min and hot air drying at $60^{\circ}C$ for 8 hrs. Samples were extracted with 70% ethanol and analyzed for free sugars, and organic acids were analyzed by HPLC. The DPPH & ABTS radical scavenging activities, crude saponin, water binding capacity, oil absorption, and ${\alpha}$-glucosidase activity were measured. The major free sugars in all samples were fructose, maltose, and sucrose, and the free sugar contents increased to 157~235% after the three-step steaming process compared to the control. Organic acid contents of samples treated by steaming increased to greater than 55.8 mg/100g. The ABTS radical scavenging activity significantly increased with repeated steaming process, especially after the three-step process. As the time of steaming process increased, DPPH radical scavenging activity increased from 26.99% fresh Dioscorea batatas to 80.46~97.79% after the three-step process. Crude saponin content increased rapidly as steaming time increased, but decreased after the three-step process steaming process. The water-binding capacities of the samples treated by steaming process were higher than that of the control, whereas oil absorption decreased as steaming time increased. From the results, steaming process could be suggested as beneficial for controlling fat intake. Compared to acarbose, a known antidiabetic drug, used as a positive control, ${\alpha}$-glucosidase inhibitory activity of samples treated by two-step steaming was among the samples. The results suggest that Dioscorea batatas treated by steaming process has antioxidative and anti-diabetis activities and can be used as a natural health product.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.2
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• pp.298-305
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• 2016

Prior research has attempted to develop a method for fermentation of onion vinegar to satisfy customer quality standard. Onion wine (OW) and onion vinegar (OV) were produced by alcoholic and acetic fermentation of onion extracts (OE) using Saccharomyces cerevisiae and Acetobacter pasteurianus, and their taste compounds (non-volatile organic acids, non-protein N compounds, and free sugars) were determined. Main components of non-volatile organic acids were malic acid (50.1%) and citric acid (26.9%) in OE, whereas malic acid (28.1%), acetic acid (20.8%), lactic acid (20.1%), citric acid (13.3%), and succinic acid (12.0%) were detected in OW. Total concentrations of non-volatile organic acids in OV were 4,612.0 mg/100 g, which was 3.9 and 2.3 times higher than those of OE and OW, respectively. Non-volatile organic acids except malonic acid and acetic acid were reduced during acetic fermentation. Non-protein N compounds increased 4.23-fold ($41,526.8{\mu}g/100g$) during alcohol fermentation, and urea content was the highest of non-protein N compounds at $33,816{\mu}g/100g$. The reduced values in OV might be used as a nutritious element of Acetobacter pasteurianus. Free sugars (glucose, fructose, and sucrose) were detected in OE, whereas only fructose was absent in OW and OV.

• Food Science and Preservation
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• v.9 no.3
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• pp.287-291
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• 2002

This study was carried out to analyze the physical peroperties and components according to kinds and harvesting season for the Quality improvement and arangement of e99plants exporting in Japan. The size and weight of chukyang eggplants were larger than those of shikibu, and those of eggplants harvested in winter were smaller than those of eggplants in summer. The pH and brix were not different between cultivar of eggplants and were small different between harvesting seasons. The contents of glucose and fructose was 115.4∼155.4, 64.2∼102.1mg/100g-fr.wt., respectively. And total contents of free sugars was 211.4∼351.1mg/100g-fr.wt. and those of chukyang was higher than those of sikibu. Total contents of free amino acids were from 73.4mg/100g-fr.wt. to 111.8mg/100g-fr.wt and was higher in chukyang than shikibu. The contents of ascorbic acid and dehydroascorbic acid was 90.0∼118.3, 28.3∼32.3mg/100g-fr.wt., respectively. And total contents of ascorbic acids were 149.4, 119.9mg/100g-fr.wt., in eggplants harvested at summer. The content of potassium and sodium was 229.97∼233.59, 135.98∼156.28mg/100g-fr.wt., respectively. The total contents of minerals was 89.35∼420.2mg/100g-fr.wt., and those of chukyang was higher than those of shikibu.

• Food Science and Preservation
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• v.11 no.3
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• pp.352-357
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• 2004

The present study was conducted to investigate extraction characteristics and antioxidative activity of Lycium chinense extracts. Lycium chinense were extracted by reflux extraction(RE) under different extraction conditions including solvent. The solid yield, turbidity, color value, titratable acidity, free sugar contents, electron donating ability(EDA) and superoxide dismutase(SOD)-like ability of Lycium chinense extracts were determined. The highest solid yield value were obtained with water of 10 fold. No significant difference in turbidity and color value were found among the extracts prepared with various extraction solvents, 75$\%$ ethanol, 50$\%$ ethanol and water. The highest titratable acidity were obtained with water of Lycium chinense. The free sugar contents of Lycium chinense extracted with water showed the highest value. Lycium chinense extracts with water included higher contents of free sugar compared with those of the other solvent extracts, 50$\%$ ethanol and 75$\%$ ethanol extracts. The total polyphenol compounds content of Lycium chinense extracted with 50% ethanol showed the highest value. Lycium chinense extracts with 50$\%$ ethanol included higher contents of total polyphenol compound compared with those of the other solvent extracts, water and 75$\%$ ethanol extracts.