• Food Science and Preservation
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• v.20 no.3
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• pp.429-434
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• 2013

This study was designed to investigate the formation of ethyl carbamate (EC) during the ripening of Maesil with sugar and Soju (19.5~35% alcohol contents) using a homemade method. Maesil, sugar and Soju were purchased at ordinary market in June of 2012. The preparation of sample for analysis was conducted by method of Henry et al. The analysis of GC/MS was used SIM mode (m/z 89, 74, 62). Quantification was performed in terms of the 62 ion and was based on an internal standard procedure. Good linearity was obtained with a regression coefficient ($r^2$ = 0.993). Low detection limits (LOD) was achieved 4.31 ug/kg and recovery for alcohol was 74.8%. During 90 days, fermentation with sugar was not detected EC (under LOQ). 15 days ripened Maesil wine contained EC between non detected~32.7 ug/kg and 90 days ripened Maesil wine was 19.7~87.4 ug/kg. Higher proportion of Maesil and Soju increased EC contents. EC levels were increased 32.7 ug/kg to 87.4 ug/kg in the ratio of Maesil to 35% alcohol-Soju (1:1). In the ratio of Maesil to 35% alcohol-Soju (1:3) was increased non detected to 69.7 ug/kg. After 90 days, Maesil wine was filtered Maesil through a seive and ripened by 180 days to investigate the formation of EC compared with non filtered. Treatment of filtered, EC contents was much higher level compared with non filtered. Therefore, this result showed that alcohol contents contribute to increase EC formation more than Maesil.

• Journal of the East Asian Society of Dietary Life
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• v.14 no.6
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• pp.582-590
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• 2004

The purpose of this study was to investigate the effect of maesil(Prunus mume) on Dongchimi fermentation. Dongchimi with 0, 2, 4 and 6%(w/v) maesil was fermented at 10℃ for 45 days. The pH of Dongchimi decreased slowly in all samples during fermentation. Total acidity of Dongchimi increased gradually during fermentation and total acidity of Dongchimi with maesil was higher than that of control. Redox potentials decreased until 30 days of fermentation but increased thereafter. Reducing sugar content increased in the initial stage of the fermentation periods, and then it decreased gradually, the reducing sugar content of Dongchimi with maesil was higher than that of control. The content of total vitamin C was much higher in Dongchimi with maesil. In color measurement, lightness value decreased gradually, redness and yellowness values increased gradually during fermentation but decreased thereafter. The content of hot water soluble pectin(HWSP) decreased as the fermentation proceeded but the content of hydrochloric acid soluble pectin(HCISP) and sodium hexametaphosphate soluble pectin(NaSP) increased.

• Food Science and Preservation
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• v.17 no.2
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• pp.214-222
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• 2010

The fermentation and quality characteristics of kimchi prepared using various types of maesil, including freshly sliced maesil (FSM), freshly ground maesil (FGM),and dried maesil powder (MP), were investigated during 25-day fermentation at 10C. The pH value decreased rapidly in the control fermentation but only slowly in maesil-supplemented kimchi. Titratable acidity values changed in the same manner. The addition of maesil significantly inhibited the growth of total aerobes, and lactic acid bacteria during fermentation over 10 days. The color (L, a, and b values) of kimchi did not differ between control and maesil-supplemented kimchi samples regardless of maesil type or concentration. Kimchi hardness did not initially differ among the various samples but decreased during fermentation. However, the hardness of maesil-supplemented kimchi was higher than that of control samples. Thus, kimchi supplemented with either 6% (w/w) MP or 6% (w/w) FGM maintained optimal hardness during fermentation. The antioxidant activity of kimchi was increased in a dose-dependent manner by addition of maesil. Kimchi supplemented with 6% (w/w) FGM showed the highest antioxidant activity. The sensory qualities (taste, flavor, color, and overall acceptability) of FSM-supplemented kimchi were better than those of control samples.

• The Korean Journal of Food And Nutrition
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• v.15 no.1
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• pp.42-50
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• 2002

This experiment was carried out to investigate the effect of Maesil extract on the acid production and growth of yoghurt starter in the skim milk medium. The Maesil extract was added to skim milk medium fur 1% to 9% and the medium was fermented by single or mixed culture of 4 types of lactic acid bacteria(Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus, bulgaricus, Lactobacillus casei). The chemical composition of Maesil, the changes in acid production (titratable acidity, pH) and number of viable cells of the medium during lactic fermentation in skim milk added with Maesil extract, and the keeping quality of curd yoghurts containing Maesil extract have determined. The composition of Maesil were 0.4% crude ash, 4.1% dietary fiber, 4.66%l citric acid, 0.264% total sugars and 405.34mg% vitamin C. The addition of Maesil extract stimulated the acid production and propagation of the lactic acid bacteria. Among the treatments tested, the addition of 3% Maesil extract with the mixed culture of Streptococcus thermophilus, Lactobacillus acidophilus and Lactobacillus casei produced the highest amount of acid(1.23%) and showed the highest number of viable cell counts(3.6$\times$10$^{11}$ cfu/mL). When the curd yoghurts containing 3% Maesil extract with the mixed culture of the lactic acid bacteria were kept at 4$^{\circ}C$ and 2$0^{\circ}C$ for 30 days, it was showed that the changes of titratable acidity, pH and number of viable cell counts of the lactic acid bacteria were not significantly different during storage. Therefore the keeping quality of the curd yoghurts adding 3% Maesil extract showed relatively good at the shelf-life.

• Food Science and Preservation
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• v.14 no.6
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• pp.645-649
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• 2007

The effects of the ratio of 45% alcohol and Maesil(Prumus mume) (1:1, 1:2, 1:3, w/v) on quality changes of Maesil liqueur during leaching and ripening for 5 months were examined. Total acidity increased with an increase ratio of Maesil and leaching and ripening periods. The pH increased as increase ratio of alcohol. The color of liqueur became dark as an increase ratio of Maesil and leaching and ripening periods. The contents of alcohol after leaching and ripening for 2 months were 24.3%(1:1), 32.2%(1:2), and 36.0%(1:3), respectively and decreased as an increase the ratio of Maesil. The contents of reducing sugar and polyphenol in the liqueur increased with an increase ratio of Maesil and leaching and ripening periods. The major components of free sugar in the liqueur were fructose, glucose, sucrose and maltose but sucrose and maltose did not detect regardless the ratio of Maesil after leaching and ripening for 2 months. The major components of organic acid in the liqueur were citric, lactic, malic, and acetic acids. The total amount of organic acid increased as an increase the ratio of Maesil but the changes of individual organic acid in the liqueur contained different ratio of Maesil showed the different tendency each other.

• Korean Journal of Food Science and Technology
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• v.50 no.6
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• pp.697-700
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• 2018

This study investigated changes in amygdalin of maesil liqueurs during leaching and ripening, and their qualities during ripening. Maesil was leached at $24^{\circ}C$ for 3 months in a commercial soju (30% alcohol). During leaching, amygdalin contents dramatically increased by 1 month, remained at a plateau by 2 months, and then decreased at 3 months. Once completion of leaching, maesil liqueurs were ripened for 3 months together with maesil (ML1) and maesil flesh itself (ML2), and without maesil (ML3). During ripening, amygdalin contents significantly decreased for all treatments, and the reduction in amygdalin rapidly proceeded in the order: ML2>ML1>ML3. Alcohol contents decreased for ML1 and ML2, while remained constant for ML3. Their pH and titratable acidity observed only subtle changes, and their color became increasingly darker. Overall results suggested that the long-term ripening of maesil liqueurs containing maesil or maesil flesh (without seeds) may resolve the concern on their amygdalin toxicity.

• The Korean Journal of Community Living Science
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• v.15 no.4
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• pp.61-66
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• 2004

To develop natural food preservatives with Maesil (prunus mume), investigation of antimicrobial activities against food-related bacteria and yeast was conducted. Maesil (prunu mume) extract exhibited growth-inhibiting activities for most of the microorganisms tested. Minimum inhibitory concentrations (MIC) of maesil extract for Staphylococcus aureus and Bacillus subtilis were as low as 0.1mg/ml. The antimicrobial activity of the maesil (prunu mume) extract was reduced by heating or alkali treatment. Moreover, growth of Staphylococcus aureus was completely inhibited within 24 hours by the addition of at least 100 ppm of maesil extract. These findings suggest that maesil extract may play a role in the development of natural food preservatives.

• Korean journal of food and cookery science
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• v.31 no.2
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• pp.112-117
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• 2015

The analytical method for ethyl carbamate (EC) in maesil (Prunus mume) extract was developed with deuterium-labeled ethyl carbamate as an internal standard. Samples were neutralized with an addition of 1 N sodium hydroxide solution, followed by a solid phase extraction with a Chem Elut cartridge. A standard curve exhibited a good linearity with correlation coefficient of 0.9991. The limit of detection (LOD) and limit of quantification (LOQ) were 2.91 ng/g and 8.83 ng/g, respectively. The recovery rate of EC ranged from 91.40% to 120.90%. The precision never exceeded 12.57% (intra-day) and 11.03% (inter-day). Samples were comprised of 24 home-made and 7 commercially-available maesil extracts. Eight home-made samples contained EC at levels between 3.39 and 75.76 ng/g. Three commercially-available samples had EC at levels between 11.67 and 20.16 ng/g. Average daily intakes of EC from maesil extracts for consumers were 0.23 g/kg of body weight. Based on a benchmark dose confidence limit ($BMDL_{10}$) of 0.25 mg/kg of body weight/day, the margin of exposure (MOE) of EC in maesil extract for consumers was 94,150, which is not of concern. Considering that a daily intake of maesil extract has been increasing, further studies on the formation of EC in maesil extract is needed.

• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.329-332
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• 2004

Changes in activities of alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) in vitro were examined by measuring maximum absorbances of ADH and ALDH at 340 nm to determine influence of Maesil (Prunus mume) on alcohol metabolism. Facilitating rates of ADH activity were 137.92, 131.58, 152,96, 218.70, 111.76, and 144.27% in Maesil juice, 5, 10, and 15% GMT, and 0.5 and 1.0% aspartic acid, respectively, ALDH activity increased in the order of Maesil juice > ALDH > GMT > aspartic acid, and facilitating rate of ALDH activity in Maesil juice was the highest at 976.44%. These results indicate alcohol metabolizing activity can be enhanced by Maesil juice.

• Preventive Nutrition and Food Science
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• v.13 no.1
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• pp.40-44
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• 2008

Response surface methodology (RSM) was used for analyzing the manufacturing process of Prunus mume extract-added vinegared red pepper paste (maesil chokochujang) with respect to sensory quality properties. Experiments were carried out according to a central composite design, selecting the amount of kochujang, amount of maesil extract, and type of sugar in the mixture as independent variables; sensory attributes such as flavor, taste, color, and mouthfeel viscosity as response variables. The polynomial models developed by RSM for sensory color and mouthfeel viscosity were highly effective to describe the relationships between the factors studied and the responses. The estimated response surfaces confirmed that the amount of kochujang had a positive effect on color (p<0.001) whereas the amount of maesil extract had a positive effect on mouthfeel viscosity (p<0.001). Increase in the amount of kochujang led to a sharp increase of the sensory score on color at all the maesil extract and sugar type levels. On the other hand, increase in the amount of maesil extract caused a sharp increase in the mouthfeel viscosity value regardless of kochujang concentration and type of sugar. The differences among samples made with different types of sugar were not significant (p>0.05).