• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.1
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• pp.143-148
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• 2012

This study evaluated the quality characteristics of white birch (Betula platyphylla var. japonica) sap with different collection times. The changes of browning index, turbidity, pH, total acidity, organic acid, free sugar, crude protein, crude ash, and mineral content were investigated. The browning index and turbidity increased from 0.076 to 0.222 and from 0.048 to 0.138, respectively, with increasing collection time. The pH decreased from 6.09 to 4.72, while total acidity increased with increasing collection time. Citric and malic acids were detected and malic acid increased with increasing collection time. Glucose and fructose as free sugars were detected and their contents were 0.364~0.433% and 0.497~0.664%, respectively. Crude protein and crude ash contents remarkably increased from 3.40 to 32.37 mg% and from 0.01% to 0.04%, respectively, with increasing collection time. Cu, Fe, Ca, Mg, Mn, and K were detected, and increased with increasing collection time. Particularly, K increased remarkably from 5.25 to 37.27 mg/L over time. These results indicate that the optimum processing method to improve the quality of white birch sap is necessary, because the quality of sap decreased as collection time increased, but nutritional value increased.

• Korean Journal of Food Science and Technology
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• v.27 no.5
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• pp.742-747
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• 1995

The effect of storage temperature and period on the contents of tin, iron, lead and vitamin C, browning index and pH was studied for canned and bottled orange juices currently sold in Korean market, which were stored for 24 weeks at 20, 30, 40 and $50^{\circ}C$ and analyzed at 4 week intervals. The change of metal content in bottled juices was negligible but metal release in canned juices was remarkably affected by storage temperature. Tin content after 16 weeks increased by $2.7{\sim}13.1$ times, iron content after 24 weeks increased by $4.3{\sim}5.2$ times and lead content after 24 weeks increased by $1.1{\sim}2.9$ times. Retention of total ascorbic acid in canned juices after 24 weeks at $30{\sim}50^{\circ}$ decreased to $13{\sim}76%$, while that in bottled juices decreased to $4{\sim}80%$. Browning index in canned juices after 24 weeks below $40^{\circ}C$ increased slightly with serious discoloration at $50^{\circ}C$ while that in bottled juices increased a little rapid. pH change in canned and bottled juices during storage below $40^{\circ}C$ was not observed regardless of container type but a great change of pH was accompanied with swelling of container ends in the case of canned juices after 24 weeks at $50^{\circ}C$.

• Korean Journal of Food Science and Technology
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• v.51 no.4
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• pp.309-315
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• 2019

In this study, the physicochemical characteristics of imported whole sesame oil (WS; WS1, WS2), imported sesame powder oil (SP; SP1, SP2), sesame oil mixed with imported whole sesame and sesame powder (WSP; WSP1, WSP2) were analyzed and their quality characteristics were compared according to the imported raw material type. $L^*$ and $b^*$ values of WS1 were the lowest and the browning index was significantly high. WS2 showed contrasting results. The redness of sesame oil was high due to its high acid value. The correlation value showed a low acid value as the content of saturated fatty acid was high. SP showed low values for antioxidant property and overall preference. The overall preference score of sensory evaluation showed the highest positive correlation with the score, suggesting that SP lacked the unique fragrance. Therefore, SP lacked the specific aroma and antioxidant property.

• Food Science and Preservation
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• v.10 no.4
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• pp.476-481
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• 2003

As its high functional properties to be used as medicine or food, the cultivation of Agaricus mushroom has been expanded and iぉ commercialization required better storage methods that can extend its functional and nutritional value for longer period. We selected drying as the most plausible method to meet such requirement, and several drying conditions were investigated to locate the optimum drying condition that can be used to keep the quality of mushroom. Drying temperature of 50$^{\circ}C$, 60$^{\circ}C$, 100$^{\circ}C$ were selected to trace the drying time required to achieve the moisture content of mushrooms less than 10%. The drying temperature at 50$^{\circ}C$ required 29 hrs of drying time, while 100$^{\circ}C$ required only 10 hrs of drying tune. However, their quality characteristics on the following categories, on the degree of browning and color were investigated to find the optimum drying condition. In addition, sensory evaluation was conducted to evaluate the quality of dried mushrooms produced by each drying condition. The browning of the mushroom was evidently increased as the higher drying temperature was used and 50$^{\circ}C$ drying produced the most desirable quality of all in pileus or stipe. The aeon of browning intensified by drying temperature was comparable to the result of whiteness index value, which resulted lower L values as drying temperature increased. and the 50$^{\circ}C$ drying resulted the most highest L values among all drying samples. As the browning and whiteness results implied, the sensory evaluation result gathered from the present research indicated that the 50$^{\circ}C$ drying was the most favorable drying condition by scoring the most highest average scores on flavors, color, appearance, and overall acceptability conducted by the 10 evaluation panels.

• The Korean Journal of Food And Nutrition
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• v.31 no.2
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• pp.258-263
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• 2018

To assess a potential possibility of Deoduck as functional food resources, this study was performed to determine the changes in chemical components and antioxidant activities on Deoduck with various aging conditions; aging temperatures were 60, 70, and $80^{\circ}C$, and aging periods were 5, 10, 15, 30, and 50 days. We determined pH, total acidity, browning index, 5-hydroxymethyl-furfural, total phenolic contents, DPPH and ABTS radical scavenging activities of aged Deoduck. Total acidity of aged samples increased during aging treatment, at higher temperature and longer time. The pH value of aged Deoduck ranged from 4.97 to 3.76. Aged Deoduck at $60^{\circ}C$ decreased slowly than 70 and $80^{\circ}C$, and these results were similar in total acidity. 5-HMF and total phenolic contents increased when increased aging temperature and periods. The DPPH and ABTS radical scavenging activities of Deoduck were ranged from 0.374 to 1.560 mg TEAC eq/g and from 0.302 to 1.745 mg trolox eq/g, respectively.

• Korean Journal of Food Science and Technology
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• v.25 no.3
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• pp.282-287
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• 1993

The effect of ethanol concentration for extraction of cinnamon on chemical and physical properties of the extracts was investigated. The cinnamon was extracted at $80^{\circ}C$ for 5 hours. High contents of cinnamic acid, aldehyde, eugenol and antioxidant activity were found in the extracts of $60{\sim}90%$ ethanol. Free sugar, tannin, degree of browning and total solids were measured relatively high in 70% ethanol extract while total amino acids and minerals were increased as the ethanol concentration decreased. The overall data suggested 70% ethanol as the most effective solvent for cinnamon extraction.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.1
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• pp.107-112
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• 1999

Physicochemical properties and microflora of kimchi stew's sauce were investigated during 6 months at 13oC, 27oC and 37oC to study the changes of its quality. The final pH values in the sauce showed a slight decrease to 4.46, 4.38 and 4.21 during storage at 13oC, 27oC and 37oC, respectively. Color(L, a, b values), salinity, moisture and Aw in the sauce were decreased during storage. However, the values of brix and browning, and the amounts of total sugar, crude protein and crude fat in the sauce were increased during storage. All the reactions occurred more rapidly in the samples stored at 37oC than those stored at 27oC and 13oC. The viable cell counts of aerobic bacteria in the sauce were changed remarkably during storage, but viable cell counts of lactic acid bacteria were decreased. Yeast, mold and E. coli were not found in the above temperatures during storage. Regression analysis between sensory scores and quality characteristics showed that the ΔE value was a major quality index for the deterioration of kimchi stew's sauce. The shelf lives of sauces at 13oC, 27oC, 37oC were estimated to be 24 months, 6 months and 6 months, respectively.

• Preventive Nutrition and Food Science
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• v.12 no.1
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• pp.40-45
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• 2007

The effects of drying methods on the physicochemical properties of chaga (Inonotus obliquus) mushroom powder were investigated. Scanning electron micrograph revealed that freeze drying produced smaller particle- sized samples which in turn resulted in higher porosity than did vacuum and hot-air drying. Samples prepared by freeze drying showed a significantly higher L*-value as compared with those prepared by hot-air drying and vacuum drying (p<0.05). The lightness (L*-value) significantly decreased with increasing relative humidity and storage temperature regardless of drying method (p<0.05). The yellowness (b*-value) increased significantly with increasing relative humidity (p<0.05). Browning index was significantly lower in samples prepared by freeze drying (p<0.05) but not significantly different between samples dried by hot-air and vacuum drying. Freeze dried sample exhibited a significantly higher degree of rehydration than other samples (p<0.05) probably due to the small particle size. Water solubility of the freeze dried sample was higher than those of the other methods while swelling ratio of the same sample appeared to be lower than those of others. Freeze dried chaga mushroom powder contained significantly lower amount of total phenolics and total sugar as compared to other samples (p<0.05).

• Food Science and Biotechnology
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• v.18 no.3
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• pp.682-688
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• 2009

Changes in lipophillic pigments concentration and its relation to color of fresh green tea liquor during heat treatment were studied. The results showed liquor greenness decreased markedly with extension of incubation time at $55^{\circ}C$, while the brightness and yellowness changed a little. Significant increase in 'a' and 'b' values of tea liquor was observed at $95^{\circ}C$. Color change of liquor at $55^{\circ}C$ was accompanied by a decrease in the level of chlorophylls, lutein and neoxanthin, and an increase in the pheophytins and ${\beta}-carotene$ levels. However, all pigments except ${\beta}-carotene$ decreased with time extension at $95^{\circ}C$. Significant correlation was found between pigments and color difference index. The browning of fresh green tea liquor was attributed to vicissitudes of lipophillic pigments during heat treatment, especially to the change of chlorophylls/pheophytins ratio. Result also showed addition of $Zn^{2+}$ at 1.6 ${\mu}mol/L$ could partially alleviate the decrease in greenness during heat treatment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.5
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• pp.714-723
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• 2021

This study investigated the quality characteristics of anchovy Engraulis japonicus sauce added with onion to improve flavor, reduce salinity, and enhance the antioxidative activity. 4 samples were prepared to find the proper amount of onion, including a control group without onion and 3 samples with different amounts of onion: 10% (Fs-10), 20% (Fs-20), and 40% (Fs-40). The samples were collected at intervals of 15 days while fermenting at 25℃ for 60 days. As the amount of added onion increased, the browning index decreased, and the flavor of anchovy sauce was enhanced. The composition of amino acids showed high content of glutamate and alanine that can improve the overall taste. In the free radical scavenging activity test, the Fs-40 group showed the highest value, 74.72%, compared to 10.98% of the control in the antioxidative activity. When evaluating overall preference such as color, fishy smell, flavor with richness, and overall acceptability, the control was rated the lowest, while the Fs-40 was rated the highest and was recognized for its overall excellence. Adding onion not only reduced salinity and increased antioxidant activity but also improved overall sensory properties by adding richness and minimizing fishy smell.