• Food Science of Animal Resources
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• v.28 no.4
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• pp.408-414
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• 2008

Low-fat sausages (LFS) containing various levels (0, 0.3, and 0.6%) of activated lactoferrin (ALF) which was prepared by dialysis to chelate irons of native lactoferrin, were manufactured and measured the physicochemical and textural properties, and shelf-life effect during refrigerated storage ($8^{\circ}C$). LFSs contained 72-16% moisture, 1-2% fat, 12-14% protein and a pH range of 6.04-6.08. No differences in physico-chemical and textural properties were observed with the increased ALF (p>0.05). Microbial growth of Listeria monocytogenes (LM), which inoculated at the levels of $10^4$ CFU/g, was increased with increased storage time. ALF at the amount of 0.6% slightly inhibited the microbial growth on the LFS (p<0.05), as compared to those of LFSs without ALF, however it had lower antimicrobial activity than those of 3.3% sodium lactate. These results indicated that the addition of ALF at the level of 0.6% affected the antibacterial activity of LFSs, resulting in the suppression of microbial growth in LFSs without quality defects.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.6
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• pp.874-881
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• 2015

In the food industry, thermal treatment is an important process for extending shelf-life of foods. However, heating process affects the physicochemical, nutritional, and microbial properties of foodstuff such as color, texture, pH, and proximate compositions. This study was conducted to select an optimal thermal treatment by observing physicochemical, nutritional, and microbial effects of shiitake mushrooms with different thermal treatment methods. Shiitake mushrooms were washed and sliced equally ($5cm{\times}0.5cm{\times}0.5cm$) and then heat-treated by three methods. Samples were heated in $100^{\circ}C$ boiling water, steamed for 10 min, or pan fried at $130^{\circ}C$ for 4 min. Total color difference values showed significantly increasing tendency with treatment time. For pH values, boiling water-treated mushrooms showed increasing tendency according to increased thermal treatment. For the results of hardness, boiling water or pan frying-treated mushrooms showed reduced tendency within 1 min. In the case of steam-treated mushrooms, hardness values were maintained for 1 min. Organic acid contents of steam-treated sample showed the lowest value among treatments. For microbial counts, steam-treated samples for 3 min showed the lowest value. Consequently, the results of this study suggest that steam treatment could be the optimal thermal treatment to minimize quality loss of shiitake mushrooms.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.9
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• pp.1219-1224
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• 2007

In this study, we explored the application of Wasabi addition to baechu kimchi with regard to quality improvement, by reviewing the optimum Wasabi level and its effects on the product physicochemical characteristics during fermentation. The final weight percentages of Wasabi in the baechu kimchi were adjusted to 0, 2, 3, 4, and 5% per weight of baechu, respectively, and the samples were fermented for 35 days at $10^{\circ}C$. Following fermentation, the treatments over 3% Wasabi contained the highest pH and lowest total acidity values. Total vitamin C and reducing sugar content increased initially, up to certain fermentation times depending on the level of Wasabi contents within the treatments over 3% Wasabi, and decreased afterwards. The water soluble pectin content increased as the fermentation period increased; however, it decreased with increasing levels of Wasabi. In conclusion, the optimum levels of added Wasabi in the baechu kimchi were 3% and 5% per weight of baechu, to have a fermentation-retarding effect on the product.

• Journal of Life Science
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• v.29 no.7
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• pp.792-799
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• 2019

This study was carried out to investigate the effect of persimmon peel on the physicochemical properties of ground pork stored at $4^{\circ}C$ for 10 days. Four types of ground pork were evaluated: T0 without dried persimmon peel powder, and T1 with 0.3%, T2 with 0.7%, and T3 with 1.0% dried persimmon peel powder. The pH increased during storage, with the pH of T3 being the lowest (p<0.01). The L-value and b-value were not significantly changed, but the a-value decreased during storage. On the 10th day of storage, the a-values were significantly higher for T2 and T3 than for T0 and T1 (p<0.001). TBARS significantly increased during storage, with lower values for T2 and T3 than for T0 and T1 (p<0.001). DPPH free radical scavenging activity decreased during storage, with T0 having the lowest value (p<0.001). The VBN content increased during storage, and the VBN content of T0 was the highest at the 10th day (p<0.05). The water-holding capacity decreased and cooking loss increased during storage. Hardness and chewiness increased, while springiness and gumminess decreased during storage. The results of this study showed that the addition of persimmon peel during the process of making ground pork had antioxidant effects that maintained redness and physical quality. A 0.7% addition was the most appropriate.

• Journal of the Korean Society of Food Culture
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• v.34 no.2
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• pp.217-223
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• 2019

This study aimed to evaluate the characteristic differential between whole cabbage kimchi (pogi kimchi) and sliced cabbage kimchi (mat kimchi) during kimchi fermentation at $6^{\circ}C$. The difference of microbial and physicochemical properties was investigated until 6 weeks. For the changes in the microbial flora, both kimchi samples exhibited a continuous increase in total aerobic bacteria and lactic acid bacteria (LAB) population size up to 2 weeks followed by a stationary phase until 5 weeks. Interestingly, the number of LAB of mat kimchi was overall higher than that of pogi kimchi during kimchi fermentation. We speculate that mat kimchi has in a more advantageous growth condition than pogi kimchi for microbial growth because small kimchi cabbage size appropriately derives nutritional supply in order to increase the LAB growth. During lactic fermentation at $6^{\circ}C$, physicochemical changes in the pH, salinity, and titratable acidity was observed to be no significant differences between two types of kimchi. Furthermore the contents of organic acids such as oxalic acid, citric acid, malic acid, lactic acid, fumaric acid, and acetic acid was not significantly different (p>0.05) between both kimchi samples as well as the contents of total free amino acid.

• Korean Journal of Poultry Science
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• v.48 no.4
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• pp.217-225
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• 2021

This study compares the physicochemical characteristics and fatty acid composition of three Korean native chickens and broilers. Ten whole raw broiler chickens and ten each from the three Korean native chickens (KNCs), Hanhyup 3 (HH3), Woormatdak 1 (WRMD1), and Woormatdak 2 (WRMD2), were purchased from the meat market. Their breast and thigh meat were used as samples. The proximate composition, pH, color, water-holding capacity (WHC), shear force, collagen content, and fatty acid composition were determined. In breast meat, the moisture content of HH3 (74.94%) and WRMD1 (74.74%) was lower than that of the broilers (77.1%, P<0.05). No significant difference was found in crude protein, lipids, and ash contents. The crude fat from thigh meat from HH3 and WRMD2 was lower than that of broilers (P<0.05). The redness of WRMD1 was the highest in both breast and thigh meat (P<0.05). The WHC of the breast meat of WRMD1 was lower than that of HH3 and WRMD2. In thigh meat, the WHC of the broilers was significantly higher than that of the KNCs. In breast meat, the shear force of WRMD2 was significantly lower than that of the broilers, HH3, and WRMD1, while no significant difference was found in thigh meat. The collagen content and arachidonic acid levels of the KNCs were significantly higher than those of the broilers for breast and thigh meats. No significant differences were observed among the KNCs. This result can be used to improve the quality of KNC but further studies on the bioactive compounds, taste, and volatile compounds of KNCs are required.

• Food Science of Animal Resources
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• v.33 no.6
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• pp.763-771
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• 2013

This study was carried out to investigate the effects of various temperatures of electro-magnetic resonance and air blast freezing methods on the physicochemical quality of meat. Beef (loin and round), pork (belly and ham) and chicken (breast and leg) were purchased at a commercial market, and the meat was frozen using three methods: air blast freezing ($-20^{\circ}C$ and $-45^{\circ}C$) and electro-magnetic resonance quick freezing. Changes in the physicochemical properties of meat were analyzed by drip loss, cooking loss, water holding capacity (WHC) and proximate compositions. In comparison, regardless of the animal species and cuts of meat, electro-magnetic resonance quick freezing (2 h) resulted in a completely frozen product in a much shorter time than $-20^{\circ}C$ and $-45^{\circ}C$ air blast freezing (24 h and 8 h, respectively). Drip loss of loin which had underwent electro-magnetic resonance quick freezing were significantly (p<0.05) lower than those of the other two treatments, but cooking loss and water holding capacity were the highest at 43.7% and 60.7%, respectively (p<0.05). Characteristics such as crude protein, crude fat and moisture compositions showed significant differences, depending on the cuts and freezing methods (p<0.05). The fat composition of electro-magnetic resonance quick frozen loin and round were significantly low (p<0.05). However, moisture content was the highest compared to other freezing methods, as 67.1% and 71.9%, respectively (p<0.05). Electro-magnetic resonance quick freezing was an appropriate way to reduce the deterioration of meat quality due to freezing, and the drip loss was least for the part with low moisture, low protein, and high fat.

• Korean Journal of Food Science and Technology
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• v.42 no.1
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• pp.33-38
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• 2010

This study was conducted to compare the physicochemical properties of powdered green teas produced in Korea and Japan including particle size, color, chlorophyll, caffeine and theanine. The average particle size of Korean powered green tea ($14.63-25.39\;{\mu}m$) was similar to that of Japanese powdered green tea ($15.46-21.02\;{\mu}m$). The surface color of shade-cultivated Haenam Green Tea (HN-1) had the highest negative 'a' value, which represents 'green' color. When the TCD (total color difference value) was measured in the samples, HN-1 was most similar to the premium powdered green tea of Japan (JA-1). Domestic shade-cultivated powdered green teas had 1.5-2 times greater chlorophyll content than powdered green teas produced from plants that were not cultivated in the shade. The presence of chlorophyll a resulted in a higher intensity of green color than the presence of chlorophyll b. A significant negative correlation was also observed between the color and the chlorophyll a, chlorophyll b and total chlorophyll contents. Specifically, chlorophyll a had the greatest impact on the green color of powdered green tea. The content of catechins, caffeine and theanine in Korean powdered green teas ranged from 14.679-20.128, 1.496-3.237 and 0.926-1.977 g/100 g, respectively. The caffeine and theanine contents were high in shade-cultivated powdered green teas. Based on the above results, domestic powdered green teas cultivated under shaded conditions had a quality similar to that of medium-quality green teas produced in Japan, and the overall quality of Korean powdered green tea was poorer than that of Japanese powdered green tea.

• Journal of Life Science
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• v.27 no.2
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• pp.123-130
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• 2017

This study was conducted to investigate the physicochemical quality characteristics of pork patty added with four different amount (T0:0%, T1:0.3%, T2:0.7%, T3:1.0%) of tangerine (Citrus unshiu) peel. There was no significant difference in chemical composition, cooking yield, water holding capacity, moisture retention, fat retention, hardness, springiness, cohesiveness, gumminess, chewiness, VBN content, L-value. In taste, texture, juiciness and palatability, the addition of 0.3%~1.0% tangerine peel in pork patty showed no significant difference on sensory properties compared to the pork patty without tangerine peel. Total polyphenol content was highest in T3, and DPPH radical scavenging activity was highest in T2 and T3 (p<0.001). The TBARS contents decreased as tangerine peel become added (p<0.001). The pH was highest in T0, and was lowest in T3 (p<0.001). The external a-value of T2 and T3 were significantly higher than that of T0 (p<0.01). The external and internal b-value of T2 and T3 were higher than those of T0 (p<0.01). Flavor of T2 and T3 were higher than those of T0 and T1 (p<0.01). In conclusion, the results of this study indicate that an addition of tangerine peel could be utilized as an ingredient in pork patty in promotion of function of tangerine by-products.

• Food Science and Preservation
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• v.16 no.6
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• pp.893-899
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• 2009

We compared the physicochemical properties of commercial brown rice vinegar fermented with and without ethanol. The pH and total acidity did not significantly differ between the two types of vinegar. Sugar content, reducing sugar content, and free sugar concentration were higher in commercial brown rice vinegar fermented with ethanol, whereas browning, turbidity, and overall color darkness were higher in vinegar fermented without ethanol. The ratio of acetic acid to total organic acids was 0.94 - 0.96 and 0.97 - 1.00 in commercial brown rice vinegar fermented with or without ethanol, respectively. A higher content of total amino acids, 93.07 - 509.48 ppm, was found in vinegar fermented without ethanol. Fermentation conditions affected the physicochemical properties of brown rice vinegar, as shown by significantly higher $\gamma$-aminobutyric acid (GABA) content in brown rice vinegar fermented without versus with ethanol.