• Quality Improvement in Health Care
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• v.5 no.2
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• pp.258-276
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• 1998

This study was conducted to justify the "prescribed shelf life" currently used in Samsung Medical Center and give recommendations based on scientific data to adopt for safe and cost-effective storage times for sterile goods Since the early 1970's, predetermined expiration dating policy has been used in Korea on all in-house sterilized products like any other countries; six months for the supplies wrapped in polyethylene peel pouches and two weeks for the rest. Recently, however, the studies suggest that current standards for preserving the sterility can be changing. It looks like we unnecessarily have too-short expiration date of sterilized supplies, that is far from being cost effective. Certainly, this research is an exciting project, especially in Korea, and will be leading and contributing to the paradigm shift of the conservative concept of shelf life for sterile supplies in Korean healthcare facilities. The major goal of this study was placed on the measurement of the recontamination time in packs wrapped in all kinds of wrapping materials used in S.M.C and stored in various conditions for periods ranging from three months to six months, and then develop a practical standard of "shelf life" based on the analyzed data. Objectives: To measure and compare the recontamination time of sterile packs among wrapppers and storage conditions, and develop a practical standard for the shelf life and storage conditions of sterile products. Samples and Method: The sterile integrity was investigated of the total 1,440 sterile sample packs containing gauze strip($1.5cm{\times}0.5cm$) we prepared and wrapped in nine wrapping materials (randomized reprocessed linens, linens reprocessed 99 times, linens reprocessed 120 times, new kraft paper, used kraft paper, new nonwoven fabrics, 6-time reprocessed nonwoven fabrics, new polyethylene peel pouches, used polyethylene peel pouches), and stored in four locations(closed cabinet of one of the typical wards, open shelf of one of ICUs, open shelf of separate storage room in ER, open shelf in OR), for three to six months, respectively in 1998. Each type of packs were opened weekly and the gauze strips inoculated into Brewer's thioglycollate broth at $35^{\circ}C$ for seven days. Results: There was no growth found for any types of the pack and storage conditions studied. Discussion: This study was conducted in an attempt to identify the possibility of extending the current shelf life for sterile goods we use in a sense of cost effectiveness. The findings suggest that we could extend our expiration dates, that means we can save a lot of materials and personnel time meeded for resterilizing, outdating, recleaning, wrapping, and reshelving. Then it will initiate a great reform in the field of healthcare in Korea, and now we are looking forward to this valuable revolution. We are going to continue this study and take all steps need to apply this new concept to our practice, and then trying to extend to other hospitals.

• Korean journal of food and cookery science
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• v.26 no.2
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• pp.165-170
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• 2010

Although the demand of ready-to-eat (RTE) foods such as Kimbab is growing, large quantities and wide distribution of these foods is difficult due to their short shelf-life, exposed packaging with hygienic risk, and decreased quality at refrigerator temperatures. This study was undertaken to develop preservation and storage methods to extend the shelf-life of RTE rice products using microwave and packaging methods such as vacuum and modified atmosphere packages. RTE rice ball samples inoculated with Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, Staphylococcus aureus or Bacillus cereus were microwave treated for 0, 30, 60, 90 and 120 seconds. Populations of pathogens on the rice balls were significantly reduced with an increase in treatment time. There were more than 5 log reductions of all pathogens when the samples were microwave treated for 60 seconds. RTE rice balls inoculated with two pathogens (S. aureus and B. cereus) were packaged via air, vacuum, $N_2$ gas, and $CO_2$ gas following microwave treatment for 90 seconds. The initial S. aureus and B. cereus concentration before treatment was 7.60 and 6.59 log CFU/g, and these levels were reduced by 3.37 and 2.18 log CFU/g after microwave treatment. The levels of pathogens were significantly increased during storage time at room temperature. $CO_2$ packaging was the most effective at inhibiting microbial growth among the tested packaging methods. The levels of total mesophilic count, S. aureus and B. cereus after 5 days of storage were 7.7, 8.8 and 9.3 log CFU/g in air packaged samples and 2.4, 3.2 and 8.3 log CFU/g in $CO_2$ gas packaged samples, respectively. However, after 3 days of storage higher levels of B. cereus were observed in all samples, indicating that the samples were not safe to be consumed. Base on these results, microwave treatment and MAP packaging methods using $CO_2$ gas could be used as a potential method for extending the shelf-life of RTE foods.

• Journal of Applied Biological Chemistry
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• v.62 no.2
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• pp.181-186
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• 2019

The optimum design of LED device for irradiation of 460 nm blue light on extruded rice cake using simulation and the effect of the blue light on the inactivation of Bacillus cereus (B. cereus) group on the rice cake were investigated. The irradiated light intensity patterns on the surface area of the sample were simulated with three different LED arrays (centered, cross, and evenly spaced) and at various distances (22, 32, 42 mm) between the LED modules and the sample. In addition, the uniformity was calculated as Petri factor. The evenly spaced array resulted the most uniform light intensity pattern in the simulation, and the Petri factor of 32 and 42 mm of the distances showed higher than 0.9, which represents the ideal uniformity of LED device. The bacterial population of the rice cake decreased to less than the initial bacterial population during exposure to LED blue light, whereas the bacterial population of the control sample increased. The bacterial count of the rice cake after blue light irradiation for 24 h was 1.21 log CFU/g lower than the control sample. Petri factor increased with increase of the distance between the light source and sample, however, the reduction rate of B. cereus group decreased. Therefore, the design of LED device, that represented the Petri factor higher than 0.9 and inactivated the population of B. cereus group, with evenly spaced and 32 mm of distance between the light source and sample was suitable for extending shelf-life of rice cake.

• 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.

• The Korean Journal of Food And Nutrition
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• v.8 no.4
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• pp.330-334
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• 1995

A various aseptic packaged cooked rice prepared In Korean rice was developed for extending shelf-life at room temperature. Data of proximate composition showed no significant difference between cultivars except moisture of cooked rice. The optimal condition of added water content for aseptic packaged cooked rice was 1.3 times of rice while 1.5 times for cooked rice and microwave heating. Hardeness of cooked rice was decreased in order of Dongjin, Odae, Chuchung, Kyaehwa, Ilpoom. Sensory evaluation results showed that Ilpoom had a best result while Odae for storage time (7 days).

• 한국유가공학회:학술대회논문집
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• 2005.10a
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• pp.11-19
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• 2005

Heat treatment is essential for hygienic safety and for extending shelf-life of milk. Heating of milk affects principally its physicochemical, nutritional and organoleptic properties. The most important changes are the decrease in whey protein solubility and the decrease in stability of casein micelles. Maillard reactions are also important and undesirable consequences.

• Korean Journal of Food Science and Technology
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• v.22 no.2
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• pp.116-122
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• 1990

In order to improve the shelf life of Tofu, the effect of calcium chloride or acetic acid as coagulants were investigated for microbial and physicochemical changes during the storage in different kinds of soaking solution. The soaking water of Tofu prepared from calcium chloride was found to be spoiled after 15-17 hours of storage at $30^{\circ}C$, by reaching the bacteria count to 10million per ml. The shelf life of the Tofu prepared from acetic acid was better than those prepared by calcium chloride. For the effect of soaking solution on storage life, soaking Tofu in 0.1% acetic acid was found to be more effective than soaking in other solutions of 3% NaCl or 0.1% K-sorbate. The optical density of soaking solution of Tofu increased in proportion to spoilage, and in case of soaked Tofu in 3% sodium chloride and 0.1% K-sorbate solution, it greatly increased. Titratable acidity, and amino nitrogen contents in soaking solution increased as spoilage of Tofu progressed, but pH decreased the early period, one or two days, of stored Tofu and then increased.

• Journal of Biosystems Engineering
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• v.40 no.3
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• pp.261-270
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• 2015

Purpose: Cold storage is the most popular method used to preserve highly perishable foods such as beef and fish. However, at refrigeration temperatures, the shelf life of these foods is limited, and spoilage leads to massive food waste. Moreover, freezing significantly affects the food's properties. Ice crystallization and growth during freezing can cause irreversible textural damage to foods through volumetric expansion, moisture migration induced by osmotic pressure gradients, and concentration of solutes,which can lead to protein denaturation. Methods: Although freezing can preserve perishable foods for months, these disruptive changes decrease the consumer's perception of the food's quality. Therefore, the development and testing of new and improved cold storage technologies is a worthwhile pursuit. Results: The process of maintaining a food product in an unfrozen state below its equilibrium freezing temperature is known as supercooling. As supercooling has been shown to offer a considerable improvement over refrigeration for extending a perishable product's shelf life, implementation of supercooling in households and commercial refrigeration units would help diminish food waste. Conclusions: A commercially viable supercooling unit for all perishable food items is currently being developed and fabricated. Buildup of this technology will provide a meaningful improvement in the cold storage of perishable foods, and will have a significant impact on the refrigeration market as a whole.

• Preventive Nutrition and Food Science
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• v.12 no.4
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• pp.284-288
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• 2007

Effect of aqueous chlorine dioxide $(ClO_2)$ treatment on the quality change of fresh ginseng during storage was examined. Fresh ginseng samples were treated with 0, 50, and 100 ppm of $ClO_2$ solution, respectively, and stored at $4^{\circ}C$. Microbiological data of the fresh ginseng after $ClO_2$ treatment revealed that the populations of total aerobic bacteria, and yeast and mold were significantly reduced with the increase of $ClO_2$ concentration. In particular, the populations of total aerobic bacteria, and yeast and mold in the fresh ginseng decreased by 2.1 and 1.2 log CFU/g at 100 ppm $ClO_2$ treatment, respectively. Aqueous $ClO_2$ treatment improved the color of the fresh ginseng during storage, but there was no significant difference in weight loss during storage among treatments. Sensory evaluation results represented that the qualities of the fresh ginseng treated with aqueous $ClO_2$ during storage were better than those of the control. These results clearly indicate that aqueous $ClO_2$ treatment could be useful in decreasing the microbial growth and extending the shelf life of fresh ginseng.

• Food Science of Animal Resources
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• v.42 no.3
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• pp.467-485
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• 2022

Supercooling storage refers to lowering the product temperature below its freezing point without phase transition and has the potential to extend shelf life. Nevertheless, supercooled objects are in a thermodynamically unstable state, and nucleation can occur spontaneously. To achieve supercooling storage, slow cooling and insulation are essential. Hence, a stepwise algorithm for the supercooling storage of pork loins was designed and validated in this study. Pork loins were stored at 3℃, -18℃, and -3℃ (freezing), and supercooled for 16 days. All samples remained in a supercooled state and were unfrozen at the end of storage. Supercooled pork loins were superior in terms of drip loss, cooking loss, and water-holding capacity compared to frozen samples. Additionally, supercooling treatment prevented discoloration, increase of volatile basic nitrogen, and microbial growth. Thus, supercooling of pork loin was achieved using a stepwise program and was effective to maintain meat quality.