• Food Quality and Culture
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• v.3 no.2
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• pp.74-81
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• 2009

This study investigated consumers' recognition on shelf life of health functional foods to set up their rational expiration date. For this study 107 male and female adults aged 20 to 59 years were randomly selected as major consumers of health functional foods. And their data were analyzed with SPSS 17.0. The questionnaire included questions asking a consumer's recognition on the shelf life of health functional foods and how to treat health function food passing its shelf life. In this study, the consumers were found to pay attentions considerably to the shelf life. But most of them did not know an accurate meaning of the shelf life of health functional food and mistook it for expiry date. In addition, the consumers doubted safety of health functional foods passing the shelf life. Therefore, education for consumers about an accurate meaning of the shelf life was needed. The results of this study were considered to be helpful to set up a reasonable expiration date for health functional food.

• Korean Journal of Food Science and Technology
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• v.19 no.6
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• pp.463-470
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• 1987

In order to develop a rapid predicting method of the shelf-life of moisture sensitive foods and establish their proper packaging methods, the qualify changes and shelf-life of dired laver as a model food were studied by the computer simulation. A mathematical model of the relationship between the rate constants of chlorophyll a and water activity was established at $10^{\circ}C,\;25^{\circ}C$ and $40^{\circ}C$. Computer simulation to predict water activity and chlorophyll a was developed by considering the simultaneous influence of storage conditions such as water content of products, storage temperature and relative humidity, packaging materials. Simulated quality changes of dried laver was in good agreement with the experiment data. Chlorophyll a and sensory score decreased as the water activity increased. And correlation coefficient between the sensory scores and the contents of chlorophyll a was very high as 0.991. The critical water activity by sensory evaluation was around 0.55. The shelf-life of dried laver packaged with plastic films could be predicted from the above results in various storage conditions.

• Korean journal of food and cookery science
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• v.28 no.6
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• pp.753-761
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• 2012

Although the mackerel is an excellent food, there are disadvantages of its own smell and its shelf-life. So this study aimed to examine the quality assessment, shelf-life and acceptability of mackerel marinated with different amounts of thyme extract through the salinity, pH, texture, change of color, and sensory evaluation for reducing the smell of it and improving the shelf-life and acceptability of it with the thyme of various physiologic activities. The salinity of mackerel marinated with different amounts of thyme was a lower 2% than that of the existing salted mackerel, 5%, when producing the salted mackerel in the experimental method of this study, reducing the intake of salt. The shelf life of the existing salted mackerel was up to 4 weeks, while that of the salted mackerel marinated with thyme extract was up to 5 weeks. The change in pH during storage showed that the salted mackerel marinated with thyme extract after 5 weeks were within the initial decomposition of dark-fleshed fishes, pH 6.2-6.4, which the shelf life was extended due to the preservative effect of antioxidant content. The acceptability test showed that T 1 marinated with 1% thyme extract was ideal in all flavor, taste and general acceptability.

• Journal of Microbiology and Biotechnology
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• v.17 no.8
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• pp.1284-1290
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• 2007

This study was conducted to investigate the antibacterial activity and shelf-life extension effect of iceberg lettuce packed in BN/PE film. The BN/PE film has a strong microbial suppression effect on pathogenic bacteria such as Escherichia coli, Salmonella enteritidis, and S. typhimurium. The number of psychrophiles and mesophiles during 5 days of cold storage of fresh-cut iceberg lettuce at $10^{\circ}C$ packaged in BN/PE film was strictly suppressed in comparison with other tested films (OPP, PE, and PET film). When fresh processed iceberg lettuce was processed and stored under the current conditions, the shelf-life of the product was longer than 5 days in the BN/PE film package, whereas the shelf-life when using the other films tested, PE, OPP and PET, was no longer than 3-4 days. The decay rates of the iceberg lettuce packed in the BN/PE film was maintained at $29.8{\pm}2.1%$ on the 5th day of preservation. The samples packed in BN/PE film maintained an excellent visual quality during the 3 days of storage without significant differences in comparison with the initial visual quality. No browning was observed in the samples packed in BN/PE film for up to 3 days. The texture of shredded iceberg lettuce packaged in BN/PE film remained unchanged up to 3 days, and then a moderate decrease in texture was observed after 4 days of storage. In addition, the overall acceptability of fresh-cut iceberg lettuce packaged in BN/PE film did not change for up to 3 days, whereas the samples packaged in the other films were inedible by 3 days of storage. In conclusion, the shelf-life of fresh-cut iceberg lettuce packaged in the BN/PE film was extended to more than 5 days at $10^{\circ}C$, whereas that in the other films was 2 days at $10^{\circ}C$. Therefore, the shelf-life extension effect of the fresh-cut iceberg lettuce in BN/PE film packaging was very effective compared with the other films tested.

• The Korean Journal of Food And Nutrition
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• v.26 no.4
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• pp.655-662
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• 2013

This study was carried out to investigate the changes in the quality properties of red pepper Yukwa (red pepper liquid fermented with lactic acid bacteria was added to the Yukwa) during the storage period. To determine the shelf life of red pepper Yukwa, the rice Yukwa (control) and red pepper Yukwa were stored at 15, 25, and $35^{\circ}C$ for 70 days. Also, the quality properties of red pepper Yukwa, such as acid value, peroxide value, texture, color, and sensory evaluation were measured. Although the acid value of rice Yukwa and red pepper Yukwa increased during storage, the red pepper Yukwa showed a lower acid value score (1.09mg KOH/g) than that (1.19mg KOH/g) of the rice Yukwa. Nevertheless, these values did not exceed the guideline maximum values of 2.0 g KOH/g specified in the Korean Food Code. The peroxide values of samples had significantly increased after 42 days. Especially, the peroxide value scores for the rice Yukwa and red pepper Yukwa were the highest at 146.49 and 126.79 meq/kg at $35^{\circ}C$, respectively. Hardness and brittleness in textural properties increased up to 70 days. The sensory values for the red pepper Yukwa for overall acceptance, taste;texture and appearance were the highest. The results indicated that by using the 'Visual Shelf life Simulator for foods' of the Korea Food and Drug Administration (KFDA) the shelf life of red pepper Yukwa is estimated to be 274.78 days.

• Food Science of Animal Resources
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• v.38 no.4
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• pp.664-678
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• 2018

This study was carried out to establish shelf life for pork cutlet of ground meat and pork lard by using various quality indicators and to understand how quality changes in these products are accelerated by temperature. The samples were selected and purchased from markets in Korea, and the chosen quality indicators were total aerobic counts and coliform group in microbiological analyses, thiobarbituric acid reactive substances assay, volatile basic nitrogen, pH, acid value, and peroxide value in physical chemical analyses, and sensory evaluation. The pork cutlet samples were stored at $-18^{\circ}C$, $-6^{\circ}C$, and $-1^{\circ}C$, whereas pork lard samples were stored at $10^{\circ}C$, $25^{\circ}C$, $35^{\circ}C$, and $45^{\circ}C$. These temperature conditions were set to real distribution conditions. The samples were then analyzed using various models including of reaction orders, arrhenius equation, and $Q_{10}$ value. The quality limits for each sample were calculated, and shelf life was estimated. The results of this experiment highlighted the importance of temperature control during the distribution process of these products and revealed that temperature is a useful parameter for the establishment of a basic database for shelf life.

• Preventive Nutrition and Food Science
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• v.12 no.4
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• pp.242-250
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• 2007

This study evaluated the storage stability of a variety of sauce products in the Korean market, determined primary quality indices for three typical products, and proposed functional relationships that are useful for determining shelf life at different temperatures. Most of the products examined were found to combine hurdles of low pH, low water activity, and the use of heat processing as methods for producing the required storage stability while maintaining the sensory quality of the products. For a meat extract solution produced for cold noodles (pH=4.3; $a_w=0.98$), the primary quality change determining shelf life was lipid oxidation, determined here by the TBA value. The primary quality index of a soybean paste seasoning mix (pH=4.0; $a_w=0.78$), which had a microbial load of 2.8 log (CFU/g), was a decrease in its pH. The primary quality index for a sandwich spread (pH=4.0; $a_w=0.88$) was changes in its surface color. The temperature dependence of changes in the primary quality indices can be described by the Arrhenius equation, which can estimate the shelf life at any arbitrary limit as a function of temperature. The activation energies for changes in the primary quality indices of the meat extract solution, the soybean paste seasoning, and the sandwich spread were 20.3, 27.2, and 43.5 kJ/mol, respectively.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.1
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• pp.124-132
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• 2018

This paper presents a shelf life assessment for K-1 military gas masks in the Republic of Korea using test data of Chemical Materiels Stockpile Reliability Program(CSRP). For the shelf life assessment, over 2,500 samples between 2006 and 2015 were collected from field tests and analyzed to estimate a probability of proper and improper functionality using Bayesian estimation. For this, three stages were considered; a pre-processing, a processing and an assessment. In the pre-processing, major components which directly influence the shelf life of the mask were statistically analyzed and selected by applying principal component analysis from all test components. In the processing, with the major components chosen in the previous stage, both proper and improper probability of gas masks were computed by applying Bayesian estimation. In the assessment, the probability model of the mask shelf life was analyzed with respect to storage periods between 0 and 29 years resulting in between 66.1 % and 100 % performances in accuracy, sensitivity, positive predictive value, and negative predictive value.

• Food Science and Preservation
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• v.2 no.2
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• pp.277-284
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• 1995

To study the shelf-life of cut cabbage kimchi, we examined the several quality characteristics of cabbage kimchi under various storage temperatures and packing materials. The pH of kimchi extracts were decreased to 4.0 in the condition of storage at 8$^{\circ}C$ during 6 days, at 4$^{\circ}C$ during 18days, 0$^{\circ}C$ during 42 days. The increase patterns of the organic acid were reverse to the changes of pH under the all conditions. The contents of reducing sugar were continuously decreased at 8$^{\circ}C$ , but increased gradually at 0$^{\circ}C$ and 4$^{\circ}C$ storage conditions. The contents of vitamine C were decreased at the early storage but increased to optimum ripening stage of pH 4.2-4.4 and after decreased continuously. The total bacterial cell counts of cabbage kimchi were increased suddenly at the early storage and after decreased gradually. And at the higher storage temperature, the more lactic acid bacteria were. On the results of sensory evaluation of cabbage kimchi at marketable shelf-life, sour taste and sour smell were significant under all experimental conditions by Duncan's multiple range test. On the above all results, we concluded that the marketable shelf-life of cut cabbage kimchi were 42 days, 19 days, 6 days at 0$^{\circ}C$, 4$^{\circ}C$, 8$^{\circ}C$ storage condition respectively.

• Journal of the Korea Institute of Military Science and Technology
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• v.22 no.4
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• pp.509-516
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• 2019

It is well known that nitroglycerin(NG) may evaporate and migrate from the triple base propellant grains in storage. This physical process makes it double base environment to the CCC(combustible cartridge case) which is based on nitrocellulose(NC) without NG. Meanwhile, it is not appropriate to use diphenylamine(DPA) as a stabilizer for CCC in this double base environment because of incompatibility between DPA and NG. So we estimated the shelf life to study the effect of NG migration from propellant to CCC by following the procedures in the STANAG 4257. And we found out that CCC with ethylcentralite(ECL) has 7.5 years longer shelf life than with DPA, when NG migrates to CCC from triple base propellant grains.