• Journal of Dairy Science and Biotechnology
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• v.36 no.4
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• pp.220-225
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• 2018

The purpose of this study was to investigate the effect of ultrasonic treatment during probiotics production process on the shelf life and the survival rate. Once Lactobacillus plantarum and Bifidobacterium longum were cultured in edible culture medium, ultrasonic treatment was performed at 100 Hz for 1, 2, 5, 7, and 10 minutes. Ultrasonic-treated L. plantarum HY7715 and B. longum HY8001 were centrifuged, mixed with a cryoprotectant, and lyophilized. The prepared lactic acid bacteria powder was individually packaged. After 6 months, viable cell counts were measured separately under cold storage and room temperature. In vitro digestion experiments were performed to determine the survival rate at digestive tract. As a result, it was observed that shelf life and survival rate were increased compared to untreated control group.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.7
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• pp.565-572
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• 2021

In this study, a study on the performance and aging of explosive bolts stored for a long time among pyrotechnic mechanical devices(PMD) used as separation devices in the defense field is conducted. For this, explosive bolts that had been installed in the weapon system for about 10 years are secured. Performance and life extension test procedures are established based on the AIAA Standard and MIL-STD. Before performance evaluation, non-functional tests are performed to check whether external changes or failures occurred. Next, circuit inspection and X-ray tests are conducted to check the failure in internal circuits and structures. After that, performance test is carried out to confirm the operation of the samples that passed the non-functional test. Through this test, separation of bolt and separation time are measured, and some samples are tested after a high temperature storage test to confirm the remaining life and the possibility of extension. Finally, the remaining life and reliability are predicted based on the results of the test and the Arrhenius model to identify remaining shelf life and reliability depend on time.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.828-833
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• 2000

The effect of treatments with alcohol, chitosan, or with both alcohol and chitosan for extending the shelf-life of Korean white rice cake and wet noodle was investigated by measuring quality changes such as total microbial count, pH, and sensory qualities. Total microbial counts for control, alcohol-treated, and 1% lactic acid-treated white rice cakes exceeded the initial putrefactive criterion level of $1{\times}10^{6}\;CFU/g$ at 6, 27 and 20 days of storage, respectively. However, total microbial count of the white rice cake treated with chitosan was still less than the criterion level even at 76 days of storage. In the case of wet noodle, total microbial counts of control and alcohol-treated groups exceeded the criterion level within 7 days of storage, while that of chitosan-treated group was far less than the criterion level even at the end of storage of 82 days. Chitosan treatment extended the shelf-lives of both white rice cake and wet noodle appreciably.

• Food Science of Animal Resources
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• v.29 no.5
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• pp.573-578
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• 2009

This study examined the effect of gamma irradiation on shelf-life extension and sensory characteristics of dak-galbi. Commercial dak-galbi sauce was gamma-irradiated at 0, 5, 10, 15, 20, 25, and 30 kGy. The dak-galbi sauce (200 g) was then added to diced chicken (800 g) for cooking, and the cooked dak-galbi samples in vacuum bags were stored at $35^{\circ}C$ for 5 d. Dak-galbi samples were analyzed on d 0, 1, 2, 3, 4, and 5 for microbial analysis (plate count agar), thiobarbituric acid (TBARS) and volatile basic nitrogen (VBN) measurements, and on d 0 for sensory evaluation. On d 0, total bacterial populations were below detection limit after dak-galbi marinated with the gamma-irradiated (${\geq}15\;kGy$) sauces were cooked, and the samples marinated with higher dose irradiated dak-galbi sauce had lower (p<0.05) bacterial populations during storage. TBARS values of the dak-galbi samples marinated with non-irradiated sauce were not different ($p{\geq}0.05$) with those marinated with irradiated sauces on d 0, and the TBARS values increased (p<0.05) during storage at $35^{\circ}C$, regardless of irradiation dose. In the VBN analysis, there was no difference ($p{\geq}0.05$) in VBN values among irradiation doses on d 0, but VBN values decreased (p<0.05) as irradiation dose increased during storage. Moreover, there were no significant differences ($p{\geq}0.05$) in sensory characteristics among irradiation doses. These results indicate that use of gamma irradiation on dak-galbi sauce may be useful in shelf-life extension without compromising the sensory characteristics of dak-galbi.

• Korean Journal of Food Science and Technology
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• v.24 no.4
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• pp.376-381
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• 1992

In order to study the effect of modified atmosphere storage on extending shelf life of mushrooms, oyster mushroom and Shiitake were wrapped with polyethylene film (PE, $50\;{\mu}m$), and stored at $0.5^{\circ}C$. Mushrooms packed with conventional hardboard box (4kg) lost marketability within $5{\sim}6$ days due to weight loss, shrinkage, browning, spore formation and/or mycellium growth. PE-packing could prevent or retard the deterioration of the mushrooms in the aspects of appearance, texture, discoloration, and microbial contamination. This situation can be best characterized by the reduced respiration rate resulted from the elevated level of carbon dioxide and the reduced level of oxygen in the bag. Although the appearance of the oyster mushroom was maintained for one month, its shelf life was limited to 15 days because of tissue softening. Discoloration of the pileus of shiitake mushroom appears to be the most important factor to determine its marketability. For example, extension of shelf life of Dongo was limited to 15 days, principally due to the browning of the pileus. Shelf life of Hawgo whose color of the pileus changed little over the experimental period, however, could be extened to more than one month.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.434-441
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• 2010

'Wonhwang' pear ($Pyrus$ $pyrifolia$ Nakai) often showed physiological disorder and quality deterioration during long-term storage and shelf life although this cultivar has the advantage of a good appearance and better taste for overseas exportation. This study was conducted to investigate the effect of temperature during transportation and continuing market temperature on fruit quality, and the occurrence of physiological disorder to set up the appropriate transportation and distribution temperatures in the fruits harvested at different times. Unripe fruits harvested 120 days after full bloom maintained higher firmness until 21days of shelf life at both 18 and $25^{\circ}C$ than late harvested ones. Otherwise, ripe fruits harvested 130 days after full bloom showed high incidence of mealiness breakdown of flesh tissues in 21 days of shelf-life at $25^{\circ}C$ of market temperature, but not in the fruits stored at $18^{\circ}C$. Late harvested fruits showed much severe physiological disorders when compared with early harvested ones that showed relatively lower respiration rates. Fruit quality parameters were more highly affected by market temperature than transportation temperature. Results showed that unripe fruits harvested at 120 days after full bloom maintains high marketability until 21 days of shelf-life, while the maximum shelf-life of ripe fruits harvested 130 days after full bloom will be considered at within 7 days.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.4
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• pp.595-600
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• 1997

To extend the shelf-life of Kochujang, the effects of anti-browning agents and their optimum concentrations were evaluated using organic acids as synergists. Among the physicochemical analyses, amino nitrogen content exhibited the highest correlation with sensory score. Ascorbic acid and citric acid were selected among the anti-browning agents(ascorbic acid, potassium sorbate, calcium chloride) and organic acids(citric acid, lactic acid, oxalic acid) tested on the basis of the highest amino nitrogen content during storage at 55$^{\circ}C$. The appropriate concentration of ascorbic acid was 0.03% based on amino nitrogen content during storage at 55$^{\circ}C$. Combination of 0.06% citric acid with 0.03% ascorbic acid showed the highest amino nitrogen content during storage at 55$^{\circ}C$. From the results, the 0.03% ascorbic acid and 0.06% citric acid were selected as additives for extending the shelf-life. Control(no additive) and additives(0.03% ascorbic acid and 0.06% citric acid) were tested for physicochemical and sensory analyses during storage at 45$^{\circ}C$ and 55$^{\circ}C$. Amino nitrogen content was also highly correlated with sensory score, The marginal amounts of amino nitrogen for control and additives were 174.9mg% and 173.2mg%, respectively. Degradation rate of amino nitrogen was a first order reaction. Compared to control, the predicted shelf-life for adding additives increased 69% and 56% at 45$^{\circ}C$ and 55$^{\circ}C$, respectively.

• Korean Journal of Poultry Science
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• v.41 no.2
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• pp.127-133
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• 2014

The effect of Lactobacillus-fermented solution (LFS) at a concentration of 0, 1 and 2% on shelf-life extension in terms of total aerobic bacteria and on color, lipid oxidation, and sensorial characteristics of injected chicken breast meat was tested during a 9-day storage period at $4^{\circ}C$. Throughout the whole storage days, addition of LFS showed the significant inhibition of total aerobic bacteria counts in chicken breast meat compared with that of control. However, the addition of LFS to chicken breast meat resulted in the decrease of pH, the increase of $L^*$ and $b^*$ values, and the increase of lipid oxidation in chicken breast meat when compared with those of control at any given storage period (P<0.05). In addition, the chicken breast meat added with LFS was subjected to low scores in sensorial properties such as flavor, taste, tenderness, and overall acceptability. The results suggested that LFS can be used for improving the shelf-life of chicken meat processing product, however, further study to prevent the deterioration of quality such as lipid oxidation and sensorial property is needed.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.574-578
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• 2009

A new red leaf lettuce (Lactuca sativa L.) cultivar, "Gopungjeokchukmyeon" which has late bolting and good red expression leaf color was developed from a cross between "Andongjeokchukmyeon" (red leaf color and late bolting) and "Dukseomjeokchukmyeon" (high yield). The cross and selection for advanced lines had been done by the pedigree method during 2000-2006. The advanced lines were evaluated for yield and adaptability at several locations in Korea (Gangwon, Kyunggi, Chungbuk, Kyungnam, Jeonnam, Jeonbuk, and Jeju) from 2007 to 2008. The "Gopungjeokchukmyeon" has gray seed color and traverse elliptic leaves. Compared to "Dukseomjeokchukmyeon", marketable yield of "Gopungjeokchukmyeon" was higher by 17% (at 330 g per plant) and Gopungjeokchukmyeon has particularly improved expression of red leaf color in high temperature cultivation in the field. The shelf-life of "Gopungjeokchukmyeon" was three weeks longer than "Dukseomjeokchukmyeon" at $4^{\circ}C$. The anthocyanin and sugar contents of "Gopungjeokchukmyeon" were higher than those of "Dukseomjeokchukmyeon" with 29.4 mg/100 g and 4.8 brix, respectively. The content anthocynin of "Gopungjeokchukmyeon" is about 10 times higher than those of "seomjeokchukmyeon". Furthermore, its taste is better, more crispy, and sweeter than those of "Dukseomjeokchukmyeon", This new cultivar "Gopungjeokchukmyeon" can be harvested all year around even summer cultivation.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.579-582
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• 2009

A new red leaf lettuce (Lactuca sativa L.) cultivar, "Mihong" which has late bolting and deep red leaf color was developed from a cross of "Danhongongchukmyeon" (deep red but early bolting and low yield) and "Hajicheongchukmyeon" (late bolting and high yield). The selection and breeding of advanced lines were done by pedigree method during 2000-2006. The advanced lines were evaluated for yield and adaptability in Korea (Gangwon, Kyunggi, Chungbuk, Kyungnam, Jeonnam, Jeonbuk, and Jeju) from 2007 to 2008. The "Mihong" has gray seed color, traverse elliptic leaves and deep red color. Compared to "Dukseomjeokchukmyeon", marketable yield of "Mihong" was higher by 2% (at 291 g per plant) as a 17.3 ton/ha, but with particularly improved good expression of deep red leaf color in high temperature cultivation in the field. The shelf-life of "Mihong" was three weeks longer than "Dukseomjeokchukmyeon" at $4^{\circ}C$. The amount of anthocyanin content of "Mihong" were higher than with "Dukseomjeokchukmyeon" at 28.9 mg/100 g. Especially the degree of leaf hardness in "Mihong" showed $26.9kg/cm^2$ compared to "Dukseomjeokchukmyeon". therefore, its taste is better, more crispy, and sweeter than "Dukseomjeokchukmyeon" This new cultivar "Mihong" can be cultivated in all year around even if summer time cultivation.