• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.1
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• pp.39-44
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• 2002

To obtain the repression of off-odor and the improvement of food quality in b1ack bean chungkugjang (BBC), some baste components of BBC added with kiwi (BBCK) or radish (BBCR) and fermented at 42$^{\circ}C$ for 3 days were investigated. Although contents of free amino acids in BBC were lower than those of soybean chung-kugjang (SC), they increased by adding kiwi and radish homogenate to black bean, indication that two materials were effective to the enzymatic digestibility of soy protein during fermentation. Among organic acids, citric acid was the most abundant, followed by acetic acid and lactic acid. Fatty acid composition was high in the order of linoleic acid (44.28~54.24%), oleic acid (18.18~22.10%) and palmitic acid(9.93~15.51%). There was no significant difference in compositions of organic acids and fatty acids of chungkugjangs. Majar volatile compounds of BBC were 2.5-dimethyl parazine and trimethyl pyrazine. Contents of alkyl pyrazines that of contribute the characteristic aroma and flayer of BBCK and BBCR decreased as compared with those of SC, respectively. Uracil and UMP were major nucleic acid-related compounds in all four types chungkugjangs. Contents of the other nucleic acid-related compounds showed a similar trend in all chungkugjangs. In sensory evaluation, kiwi and radish were effective to repression of off-odor from chungkugjang. Sweet taste of stew of black bean chungkugjang was strong as compared with that of soybean chungkugjang, indicating that palatability of BBCK or BBCR was good.

• Korean Journal of Food Science and Technology
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• v.29 no.1
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• pp.115-119
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• 1997

The chemical and microbial properties and acceptability of milk and soymilk inoculated with Bifidobacterium were studied at each storage time (0, 5, 10, 15, 20, 25, and 30 days). Soymilk, milk, low-heat milk, low-fat milk, non-fat dry milk with Bifidobacterium longum ATCC 15707 were incubated in a nitrogen-carbon dioxide atmosphere at $4^{\circ}C$ for 30 days. pH and acidity of all the samples were in the range of $pH\;6.6{\sim}pH\;6.9$ and $0.4%{\sim}0.55%$ for 30 days, respectively. The viable cell numbers in non-fat dry milk reached above $8.4{\times}10^9\;CFU/mL$ after 15 days. The glucose content in soymilk was $4.5{\times}10^{-2}{\sim}5.5{\times}10^{-2}\;mM$ at 10 days of storage. Milk and soymilk containing B. longum at $4^{\circ}C$ were found to be different in taste, odor, off-flavor at each storage time (0, 2, 4, 6, 8, and 10 days). Sensory scores indicated that milk containing bifidobacteria was poorly affected by the storage time, but milk at 4 days of storage was quite close in odor and off-flavor to milk with storage time 0. Soymilk containing bifidobacteria at 2 and 4 days of storage had significantly higher acceptability of taste than soymilk with storage time 0.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.6
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• pp.761-767
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• 2006

To determine freshness and quality change of chicken products during storage, we manufactured freshness indicator and monitored the surface pH, volatile basic nitrogen (VBN), thiobarbituric acid reacted substance (TBARS), total bacterial counts, electronic nose analysis, and sensory evaluation. All chicken products (drum, wing, thigh) had a change in color of freshness indicator after storage of 3 days at $4^{\circ}C$, indicating poor quality at the time. VBN, TBARS values, and total bacterial counts reached the decay point at the time of color change of freshness indicator attached to the surface of chicken samples. The sensory evaluation also indicated sample was not acceptable by off-odor at day 4 of storage. According to electronic nose analysis to examine off-odor, there were significant differences in terms of principal component analysis values among chicken samples of day 0, day 3, and day 5 of storage. These results suggest that freshness indicator should be useful in determining expiration date of chicken products during marketing by indicating the microbial safety as well as physicochemical and sensory change.

• Horticultural Science & Technology
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• v.35 no.3
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• pp.314-322
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• 2017

The aim of this study was to determine suitable oxygen transmission rate (OTR) films for modified atmosphere (MA) storage of asparagus spears (Asparagus officinalis L.), and to examine the related changes in asparagus spear quality. Asparagus spears were packed with 10,000, 20,000, 40,000, 70,000, and $100,000cc/m^2{\cdot}day{\cdot}atm$ OTR film treatments for MA storage, and perforated film (conventional storage) was used as the control. The fresh weight loss rate was less than 1% in all OTR film treatments but not in the control. In all OTR film treatments, ethylene content rapidly increased on the first day of storage, and gradually decreased thereafter to $2.0{\mu}L{\cdot}L^{-1}$ by the final storage day. In the 10,000 cc and 20,000 cc OTR film treatments, carbon dioxide content was maintained within the permissible range for asparagus spears under recommended controlled atmosphere (CA) and MA conditions (5-12%). The oxygen content was maintained between 12% and 20% in all OTR film treatments. Hue angles and total chlorophyll content were highest in the 10,000 cc OTR film treatment in both tips and stems. Visual quality was maintained at a saleable level only in the 10,000 cc OTR film treatment until the final storage day (25 days). Based on sensory evaluation, the least off-odor was detected in the 10,000 cc OTR film treatment, and the most in the control treatment. While the soluble solids content decreased with all film treatments, it was maintained at the highest level in the 10,000 cc OTR film treatment. Vitamin C content decreased with all film treatments during storage, but was maintained at higher levels in the 10,000, 20,000, and 40,000 cc OTR film treatments. The firmness of tips and stems increased with storage duration in all film treatments, stems were firmer under the perforated film, 10,000, and 20,000 cc OTR film treatments. Given these results, the 10,000 cc OTR film treatment is considered the most appropriate for MA asparagus spear storage since visual quality and soluble solids content were maintained, and fresh weight loss, vitamin C content, off-odor, and yellowing were suppressed during storage.

• Food Science and Preservation
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• v.15 no.1
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• pp.144-149
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• 2008

Physiological, sensory and microbiological evaluations were conducted during fermentation of Chungkookjang. with Choi-cha (non-fermented green tea) powder in efforts to improve the sensory quality of Chungkookjang. Growth of fermentative microorganisms in Chungkookjang was inhibited by Choi-cha; the pH and VBN value decreased as the concentration of Choi-cha increased. Brightness (L) and redness (a) of Chungkookjang fermented with Choi-cha were significantly decreased, resulting in the appearance of all samples fermented with Choi-cha being less attractive than was the control. The sensory quality of Chungkookjang was significantly increased when Choi-cha was added up to 3%, (w/v), and off-odor was reduced. The antioxidative property of Chungkookjang fermented with 3% (w/v) Choi-cha was significantly higher than that of the control. This result indicated that the sensory quality of Chungkookjang was improved by fermentation with 3% (w/v) of Choi-cha powder.

• Journal of Korean Society of Forest Science
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• v.106 no.1
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• pp.26-32
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• 2017

We studied the effects of dip treatments of natural extracts (Camellia sinensis, Angelica gigas, Astragalus membranaceus, Glycyrrhiza uralensis: 1% extract) on the quality of peeled 'Daebo' chestnut. After dipping treatment peeled chestnuts were vacuum packaged with $75{\mu}m$ PE+Nylon 7-layer film then stored in $4^{\circ}C$ incubator for 35days. The quality changes including the surface color and off-odor were evaluated for storage days. The natural extracts dipping treatment on peeled chestnut was effective on skin browning inhibition. Especially, Astragalus membranaceus and Glycyrrhiza uralensis extract treatments was significantly effective in reducing surface browning. The color change (${\Delta}E$) of peeled chestnut was the highest (5.6) in control, whereas that was the lowest (3.4) under Astragalus membranaceus extract treatment at 35 storage day. The natural exteacts treatments had no effect on the weight, the mositure loss rate, the firmness and the soluble solid contencts of peeled chestnuts during storage after treatment. The decaying rate of peeled chestnut was 9.0% in control, 9.0% in Camellia sinensis extract treatment, 9.0% in Angelica gigas extract treatment, 21.0% in Astragalus membranaceus extract treatment, and 7.0% Glycyrrhiza uralensis extract treatment at 35 storage day. Sensory evaluation revealed significant differences in off-odor and color attributes. After all, the score of overall sensory evaluation was the lowest in Astragalus membranaceus extract treatment and the highest in Glycyrrhiza uralensis extract treatment. As the results, the natural extract treatments, especially with vacuum packing after Glycyrrhiza uralensis extract treatment, extended the shelf-life of the peeled chestnut by inhibiting the surface browning.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.2
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• pp.133-142
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• 2022

Korean enoki mushrooms are exported to Southeast Asia and the United States, where there are complaints due to quality deterioration during the distribution process. In this study, we evaluated the efficacy of vacuum film packaging on quality maintenance in Korean enoki mushrooms during simulated vessel export to Vietnam using selected film, which was developed with vacuum packaging machine and oxygen absorber. We selected two MA film, one was 2-layerd 30 ㎛ CPP film (control) and the other was 3-layered 30 ㎛ CPP film (treatment) which is optimized film of higher gas and moisture permeability. The Korean enoki mushrooms were packaged with these two films using PAC-2000 or PAC-3000 vacuum packaging machine which was improved vacuuming of higher speed. Packed mushrooms were stored at 1℃ for 2 weeks and distributed at 20℃ for 2 days or 8℃ for 6 days. The efficiency of the film packaging was analyzed by vacuum maintaining index, and overall the quality characteristics such as off odor, color, cap cleavage, stem elongations and sensory evaluation were evaluated during storage and distribution. Results suggest that postharvest loss of fresh enoki mushroom could be reduced by packaging mushroom with 3-layered 30 ㎛ CPP films packaged using PAC-3000 machine during simulated vessel export to Vietnam due to vacuum maintaining. Oxygen absorber promoted off-odor at 20℃ distribution temperature, and did not affect storability at 1℃ storage compared to treated group without oxygen absorber treatment.

• Korean Journal of Food Science and Technology
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• v.35 no.2
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• pp.166-172
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• 2003

Changes in the number of microorganisms, chemical composition, and sensory quality of chungkukjang by gamma-irradiation up to 120 kGy were investigated. The total viable cell counts in chungkukjang irradiated with 10 kGy decreased from $10^9\;CFU/g$ of the control to $10^5\;CFU/g$. Proximate chemical composition and pH of chungkukjang were not much affected by irradiation. Acidity of chungkukjang decreased by irradiation with over 20 kGy. Fatty acid contents of chungkukjang irradiated under 20 kGy were the same as those of the nonirradiated ones. Polyunsaturated fatty acids content, decreased at over 40 kGy. The color and odor of chungkukjang were not significantly affected by irradiation up to 20 kGy. Unpalatable odor (p<0.01), off-flavor (p<0.001), and fish-odor (p<0.001) increased, and brown intensity (p<0.05) and acceptability (p<0.001) decreased at over 20 kGy. Results indicate 20 kGy is sufficient to decrease the microbial count of chungkukjang and prevent decrease in the content of polyunsaturated fatty acids.

• Korean Journal of Food Science and Technology
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• v.4 no.2
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• pp.100-105
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• 1972

This experiment was conducted to investigate the combined effects of radiation and antiseptics on the keeping qualities of pork sausage, which was treated with potassium sorbate and AF-2(2-(-2-furyl)-3-(5-nitro-2-furyl)-acrylamide), and then followed by gamma radiation of 0.25, 0.5, and 0.75 Mrad. Amounts of treated antiseptics were a quarter, half, and full levels of their maximum permissible concentration. Irradiated and unirradiated sausages were stored for 50 days at $5^{\circ}C\;and\;25^{\circ}C$, and their changes in rancidity, volatile basic nitrogen, bacterial counts, pH, and sensory analysis were examined during the storage period. The results obtained are as follows: 1) Preservative effects of antiseptics were manifested at cold storage; antiseptics treatment of a quarter-level and unirradiation following low-temperature storage showed the same good keeping qualities as the combined treatment of full-level antiseptics and radiation of 0.25 Mrad following high-temperature storage. 2) There did not appear to recognize irradiation-odor, while color and odor were deteriorated intensively by storage temperature. Sausage irradiated with 0.75 Mrad has shown slightly noticeable off-odor at the end of storage at $25^{\circ}C$. 3) The most suitable radiation dose was considered to be 0.5 Mrad, which could extend the storage life about $2{\sim}3$ times longer than untreated.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.2
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• pp.259-266
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• 2011

This study was performed to develop an odor-reduced Korean traditional Cheonggukjang (fermented soybean paste) by adding Job's tears to Cheonggukjang made with soybean (control) only. The study included the determination of best addition percentage of Job's tears versus soybean, sensory evaluation, and aroma patterns and its components as well as proximate composition analyses of Cheonggukjang. Job's tears Cheonggukjang (CAJT) was prepared by inoculating Bacillus subtilis and fermented at $40^{\circ}C$ for 48 hours. Ratios of soybean : Job's tears for Job's tears Cheonggukjang were 1:1, 2:1, 3:1, and 4:1, respectively. In comparison of proximal composition, Job's tears Cheonggukjang was high in moisture and carbohydrates, but low in calorie, fat, protein, ash and amino nitrogen. The pH of CAJT was lower than those of control and conventional Cheonggukjang (CC) sold in the market, and the acidity was the lowest in CC. The color of Job's tears Cheonggukjang appeared the whiter and more yellowish, but less reddish in proportion to contents of Job's tears. The contents of viscous substances were higher in CAJT compared with those of control and CC. The contents of glutamic acid, the major components of viscous substances were lower in CAJT than in control and CC, and the contents of fructose higher in CAJT. The scores of sensory evaluation were the highest in Job's tears Cheonggukjang mixed with soybean : Job's tears=4:1. The aroma pattern of CC analyzed was conspicuously dissimilar to the control and CAJT and also discriminated by electronic nose examination. The pyrazines, volatile compounds peculiar to Cheonggukjang, were found to be lower in CAJT by SPME-GC/MS assay. Additionally, the acetic acid, butanoic acid, and naphthalene causing off-flavor were identified in CC, but not in Job's tears Cheonggukjang. The strength of odor through sensory evaluation was by far the lowest in CAJT among the groups. From the findings, it had shown that Job's tears Cheonggukjang would be produced successfully when the ratio of 4:1 (soybean : Job's tears) is employed. Also, it was proved that appropriate ratio of Job's tears addition makes Cheonggukjang odor-reduced and well accepted by people.