• Journal of Food Hygiene and Safety
• /
• v.22 no.4
• /
• pp.323-331
• /
• 2007

This study was designed to estimate self-life of Kimbab and sandwiches marketed in convenience store. While the 12 different type of Kimbab (n=6) and sandwiches (n=6) were kept at $10^{\circ}C$ for 72 hours, quality changes including volatile basic nitrogen, aerobic plate count, pathogens detection and sensorial property was monitored, and effective quality indicators were selected. Volatile basic nitrogen, indicator for protein deterioration was slightly increased during storage periods in all samples. E. coli, Staphylococcus aureus, Salmonella spp. and Vibrio parahaemolyticus were not detected from any of samples. Change of aerobic plate count of Kimbab and sandwiches were increased moderately but increased dramatically after 48 hours of storage. Overall acceptability were maintained over 5, purchasing power limit, for 40 hours in 4 general Kimbab, 48 hours in 2 samgak Kimbab and 42 hours in 2 sandwiches. Shelf-life of each item was calculated from regression equation between reference limit from effective quality indicators, aerobic plate count and sensory property, and storage period. Estimated shelf-lives of general Kimbab were $15{\sim}33$ hours, samgak Kimbab were 32 hours and sandwiches were $27{\sim}30$ hours at $10^{\circ}C$ refrigerated condition.

• Applied Biological Chemistry
• /
• v.45 no.1
• /
• pp.11-17
• /
• 2002

Fermentation characteristics with/without nitrogen source and quality of the fruit distillate of Opuntia ficus-indica var. saboten were investigated during the manufacturing process of a Korean traditional liquor. As the fermentation period increased, acidity, brix degree, and alcohol concentration increased, whereas pH and contents of reducing sugar decreased. Acidity, pH, and brix degree were higher, whereas the content of reducing sugar lower, in the nitrogen source-added distillate than in the distillate without nitrogen source. The growth of yeast increased, while that of bacteria decreased; this trend was more prominent with the addition of a nitrogen source. Sojues, distilled from two types of mashes and diluted with $H_2O$ and tails of distillate into 22% alcohol concentration, showed pH $3.7{\sim}4.0$, acidity $0.02{\sim}0.10$, and $5.4{\sim}6.1$ $^{\circ}Brix$. Analysis through GC using direct injection methods revealed common volatile flavor compounds in sojues, including acetaldehyde, acetyl acetone, acetic acid ethyl ester, ethyl alcohol, 2-propyl alcohol, acetone, n-propyl alcohol, butanoic acid methyl ester, 2-phenyl ethanol, thymol, acetic acid phenyl ester, and vanillic aldehyde. As revealed through the sensory evaluation, no significant difference (p>0.05) in overall acceptability was shown among four experimental groups, while color and flavor showed significant differences(p<0.05).

• Food Science and Preservation
• /
• v.23 no.2
• /
• pp.145-154
• /
• 2016

This study investigated the possibility of usage of freeze-dried ingredients for the preparation of Nabak kimchi. The quality characteristics of Nabak kimchi using freeze-dried ingredients (radish, kimchi cabbage, green onion, garlic and ginger) were monitored during storage at $4^{\circ}C$. The initial pH of Nabak kimchi was 5.76~5.93, however, it decreased significantly over increasing storage periods (p<0.05). The titratable acidity of Nabak kimchi increased during storage, reaching 0.43~1.08%. Among the freeze-dried samples, those treated with freeze-dried radish and minor ingredients showed lower titratable acidity than that of the control. The initial number of total aerobic and lactic acid bacteria were 5.57~6.25, and 5.52~6.24 log CFU/g, respectively. After 28 days, the population of total aerobic and lactic acid bacteria in the raw ingredients and freeze-dried minor ingredients was less than 8.0 log CFU/g, but more than 9.0 log CFU/g in other samples. Yeasts and molds in Nabak kimchi were detected up to 2~3 log CFU/g, but coliforms were not detected in all samples during storage. The score of firmness and overall acceptability in the control, raw ingredients and freeze-dried minor ingredients were significantly higher than others (p<0.05). These results indicated that freeze-dried ingredients, such as green onion, garlic, and ginger, can be used in kimchi and would delay microbial growth and extend the shelf-life of kimchi without any deduction of sensory quality.

• Food Science and Preservation
• /
• v.22 no.4
• /
• pp.505-511
• /
• 2015

This study was performed to investigate the effect of drying temperature on the quality characteristics and antioxidant activity of blueberry. Blueberries were dried at different times and temperatures, including A ($40^{\circ}C$, 72 hr), B ($40^{\circ}C$, 48 h and $50^{\circ}C$, 24 hr), C ($50^{\circ}C$, 72 hr), and D ($60^{\circ}C$, 72 hr). The yield and pH ranges of blueberry were determined to be 17.73~31.17% and 3.20~3.25, respectively. The yield rate of A treatments, soluble solid of D treatments, was the highest. The yield rate and soluble content was the highest in the treatment of A and D, respectively. The moisture content and water activity were significantly decreased with the increase in drying temperature (p<0.05). The L value of A treatment, and a and b values of D treatment were the greatest. In the analysis of texture analyzer, hardness, springiness, cohesiveness, gummiess and chewiness were significantly increased with the increase in drying temperature (p<0.05). In the sensory evaluation of blueberry, the appearance and color were the highest in the A treatment. The moisture, texture and taste was highest in the B treatment. The overall acceptability was in the order of B > A > C >D. The total polyphenol content and DPPH radical-scavenging activity were 9.21~13.05 mg/GAEg and 61.90~81.42%, respectively, which were significantly decreased with the increase in drying temperature (p<0.05). Therefore, the optimum time and temperature for blueberry drying was founded to be B treatment ($40^{\circ}C$, 48 hr and $50^{\circ}C$, 24 hr) among other treatments.

• Food Science and Preservation
• /
• v.15 no.2
• /
• pp.174-184
• /
• 2008

The quality and storage characteristics of low salted onion and five cereals-doenjang (DFO) were investigated. At the DFO, soybean koji ($57{\sim}62%$), onion (3%) and salt (8%) were mixed with equal amount of rice, barley, glutinous millet and glutinous indian millet ($10{\sim}30%$), and water ($7{\sim}12%$). The storage of DFO was done by vacuum packing in polypropylene tube, and sterilized at $121^{\circ}C$. The fermentation and storage was conducted for 60 days at $25^{\circ}C$ at each condition. Control doenjang (GD) was the salinity of 16% soybean doenjang that was not sterilized and packed in plastic containers for storage. During the fermentation, pH of DFO was lower than GD. The pH maintained stability during the storage, and revealed to be lowered, as the proportion of mixed cereals was higher. During the fermentation of DFO, the brix degree revealed to be higher than GD and maintained s1ability during the storage. During the fermentation and storage, the amino nitrogen content of DFO was ranged $400{\sim}470mg%$ by showing higher content than GD and maintained stable content during the storage. During the fermentation, the activities of protease and ${\beta}$-amylase were maintained to be high at DFO, but the activities during the storage were high at GD. The color $L^*$ value of DFO during fermentation and storage maintained higher values than GD, but $a^*$ value revealed lower pattern. Total free amino acids of DFO was ranged $1,918{\sim}2,290mg%$ which was higher than GD that recorded 1,291 mg%. When the sensory evaluation was conducted for DFO that was fermented and stored for 60 days, the DFO mixed with $20{\sim}30%$ of cereals resulted to have more savory taste, flavor, and sweeter than GD, and overall acceptability for color and overall taste was high.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.40 no.1
• /
• pp.110-115
• /
• 2011

Shelf-life of brined baechu cabbage was extended by pasteurization at $65^{\circ}C$ for 30 min. Starters (Leu. citreum and Lab. plantarum) were added to the pasteurized brined cabbage to supply beneficial lactic acid bacteria during kimchi fermentation. Control kimchis made with baechu cabbage without pasteurization and no addition of the starters to the pasteurized cabbage kimchi were also prepared. The fermentation characteristics and health functionalities of DPPH free radical scavenging activities and in vitro anticancer effects in AGS human gastric cancer cells were compared. The pasteurized brined cabbage could not be fermented well and the functionalities were also low; however, the addition of starter(s), especially mixed starters of Leu. citreum and Lab. plantarum to the pasteurized brined cabbage, significantly increased the counts of lactic acid bacteria, hardness (texture) and overall acceptability in sensory evaluation. The free radical scavenging activities and the anticancer effects were also increased. The fermentation patterns of starter added kimchi prepared with pasteurized brined cabbage were similar to those of naturally fermented kimchi. It seemed that growth of lactic acid bacteria during kimchi fermentation contributed to increased taste and health functionality of kimchi.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.46 no.1
• /
• pp.61-67
• /
• 2017

Chia seed (Salvia hispanica L.) originated from Central America is a highly nutritious food containing large amounts of linolenic acid, dietary fiber, and protein. This study investigated the quality properties and antioxidant activities of Sulgidduk prepared with chia seed powder as a functional material. Freeze-dried chia seed powder was replaced with 0, 1, 3, 5, and 7% of rice flour. The addition of chia seed powder did not affect water content, whereas the pH value of the chia seed group decreased as compared to the control. For color measurements, a and b values increased as the amount of chia seed powder increased, whereas L value decreased. Hardness and chewiness of Sulgidduk with chia seed powder were lower than those of the control, whereas springiness of the chia seed group was higher than that of the control. Cohesiveness was not significantly different in all samples. According to retrogradation analysis based on changes in hardness during storage, it was confirmed that addition of chia seed powder inhibited aging of Sulgidduk. Retrogradation of CSP5 was the slowest. Consumer acceptability analysis did not show significant differences in all samples. Total polyphenol and flavonoid contents tended to significantly increase as chia seed content increased. DPPH and ABTS radical scavenging activities of Sulgidduk were also elevated due to addition of chia seeds. From the results, addition of chia seed softened texture, inhibited aging, and enhanced antioxidant activities of Sulgidduk. It is concluded that addition of 5% chia seed powder, which showed high effectiveness for aging, is the most suitable for commercialization.

• Journal of Life Science
• /
• v.18 no.11
• /
• pp.1521-1531
• /
• 2008

After pigs was fed by commercial diets supplemented with various concentrations (0, 0.5, 1, and 1.5%) of the fermented mushroom by-product of Pleurotus eryngii, the meat qualities and the serum lipid compositions of the individual pig groups were investigated. The levels of total lipid, total cholesterol, and triglyceride in the serum were significantly lower when the pigs were fed with the diet supplemented with 1.5% fermented mushroom by-product than those of the control pigs. HDL-, LDL-, and VLDL-cholesterol contents in the serum exhibited no significant difference between the pig group fed by the diet containing the fermented mushroom by-product and the control group. In comparison to the control group, the pig group fed by the diet supplemented with 1.5% fermented mushroom by-product showed significantly lower level of AI, CRF, GOT, and LDH values in the serum, whereas the difference in the level of antioxidant activity of the serum was not significant. Sensory evaluation regarding color, off-flavor, tenderness, juiciness, and overall acceptability also showed that the pork from the pig group fed by the diet supplemented with the fermented mushroom by-product ($0.5{\sim}1.5%$) was better than that from the control group. Although enhancement in the lghtness ($a^*$) value of the pork was significant in 20 days of storage at $4^{\circ}C$, the redness ($L^*$) value was not significantly differential during the storage periods regardless of the supplementation of the fermented mushroom by-product into the diet. The cooking loss of the pork from the pig group fed by the diet supplemented with the fermented mushroom by-product (1% and 1.5%) decreased in the storage 10 days, but it increased in the storage 20 days. After storage for 20 days at $4^{\circ}C$, shear force of the pork obtained from the pigs fed by the diet supplemented with $1%{\sim}1.5%$ fermented mushroom by-product appeared to become significantly lower than that of the control. There were, however, no significant changes between two groups in the level of moisture content, crude lipid, and pH during the storage period. Although the TBARS content was enhanced in all groups during the storage period, the enhancement appeared to be more significant in the pork from the pig group fed by the diet containing the fermented mushroom by-product in comparison to the control. On the other hand, the ratio of UFA/SFA for the pork obtained from the individual pig groups showed no considerable diet-associated alterations during the storage period.

• Korean Journal of Food Science and Technology
• /
• v.38 no.3
• /
• pp.392-399
• /
• 2006

In order to develop a new persimmon pickle with a low salt concentration, changes in physicochemical characteristics during soaking of persimmon pickles treated with different organic acids and sugars were investigated at $15^{\circ}C$ for 70 days. The pH of persimmon pickles decreased from pH 6.64 at initial stage to pH 3.99 (control group), pH 2.76-3.33 (citric acid treatment, CT), and pH 3.08-3.34 (acetic acid treatment, AT) after 70-days of soaking. Titratable acidity of AT was higher (0.86-1.18%) than that of CT (0.61-0.78%). After 70-days of soaking, salinity of persimmon pickles treated with stevia leaf powder, sodium saccharin, sucrose, and isomalto-oligosaccharide were 4.94-4.96, 4.00-5.15, 2.99-3.31, and 3.03-3.30%, respectively, and 1.54-3.70% lower than that of the control group (6.69%). The hardness of persimmon pickles in all cases was increased up to 20-40-days of soaking and then decreased. L (lightness), a (redness), and b (yellowness) value of persimmon pickles treated with citric acid were higher than those of AT and the control group. Sensory evaluation of persimmon pickles after 70-days of soaking revealed that CT had the highest scores for color, texture, and overall acceptability. These results indicate that the salt concentration of persimmon pickles could be lowered by the addition of citric acid and various sugars during soaking.

• Korean Journal of Poultry Science
• /
• v.41 no.2
• /
• pp.77-85
• /
• 2014

This study was conducted to investigate the effect of duck and pork meat mixing ratio on quality characteristics of emulsion type sausage at $4^{\circ}C$ during 5 weeks. Treatments on the basis of the meat content were subjected to 100% duck meat (T1), 100% pork meat (T2), 50% duck meat + 50% pork meat (T3), 40% duck meat + 60% pork meat (T4), and 30% duck meat + 70% pork meat (T5). The moisture content was significantly (p<0.05) higher in TI sample but significantly (p<0.05) lower in T2 sample than those in comparison to the other treatments. Crude protein and fat content were significantly (p<0.05) higher in T2 sample compared to the other treatments. CIE $L^*$value was significantly (p<0.05) lower in T1 sample than those of other treatments until 5 weeks of cold storage. CIE $a^*$value was significantly (p<0.05) higher in T1 sample but significantly (p<0.05) lower in T2 sample than those in comparison to the other treatments until 5 weeks of cold storage. Hardness was significantly (p<0.05) higher in T4 sample compared to the other treatments during all cold storage. Cohesiveness was significantly (p<0.05) higher in T5 sample compared to the other treatments until 2 weeks of cold storage. The results of sensory evaluation showed that the meat flavor, taste and texture were significantly (p<0.05) lower in T5 sample compared to the other treatments whereas no difference among treatments except T5 sample. Overall acceptability was significantly (p<0.05) lower in T5 sample compared to the other treatments. Therefore, these results suggested that the ratio of 40% duck meat and 60% pork meat is appropriate levels for hardness and palatability when manufacturing emulsion type sausage with duck meat.