• Food Science and Biotechnology
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• v.18 no.5
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• pp.1243-1252
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• 2009

User-friendly software was developed to determine the shelf-life of perishable Korean seasoned side dishes in real time based on growth models of spoilage and pathogenic microorganisms. In the program algorithm, the primary spoilage and fastest-growing pathogenic organisms are selected according to the product characteristics, and their growth is simulated based on the previously monitored or recorded temperature history. To predict the growth of spoilage organisms with confidence limits, kinetic models for aerobic bacteria or molds/yeasts from published works are used. Growth models of pathogenic bacteria were obtained from the literature or derived with regression of their growth rate data estimated from established software packages. These models are also used to check whether the risk of pathogenic bacterial growth exceeds that of food spoilage organisms. Many example simulations showed that the shelf-lives of the examined foods are predominantly limited by the growth of spoilage organism rather than by pathogenic bacterial growth.

• Food Science of Animal Resources
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• v.29 no.3
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• pp.289-295
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• 2009

The aim of this research was to develop predictive models for the growth of spoilage bacteria (total viable cells, Pseudomonas spp., and lactic acid bacteria) on frankfurters and to estimate the shelf-life of frankfurters under aerobic conditions at various storage temperatures (5, 15, and $25^{\circ}C$). The primary models were determined using the Baranyi model equation. The secondary models for maximum specific growth rate and lag time as functions of temperature were developed by the polynomial model equation. During 21 d of storage under various temperature conditions, lactic acid bacteria showed the longest lag time and the slowest growth rate among spoilage bacteria. The growth patterns of total viable cells and Pseudomonas spp. were similar each other. These data suggest that Pseudomonas spp. might be the dominant spoilage bacteria on frankfurters. As storage temperature increased, the growth rate of spoilage bacteria also increased and the lag time decreased. Furthermore, the shelf-life of frankfurters decreased from 7.0 to 4.3 and 1.9 (d) under increased temperature conditions. These results indicate that the most significant factor for spoilage bacteria growth is storage temperature. The values of $B_f$, $A_f$, RMSE, and $R^2$ indicate that these models were reliable for identifying the point of microbiological hazard for spoilage bacteria in frankfurters.

• Plant Resources
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• v.8 no.3
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• pp.230-234
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• 2005

This study was conducted to determine feasibility of utilization of Angelica acutiloba. Especially, the quality characteristics of bread prepared with the addition of Angelica acutiloba powder were investigated. Sensory evaluation and spoilage test were conducted for preparation of functional breads which added with ground plant matters (leaves and stems) from Angelica acutiloba. The result showed that the functional breads had high score of overall liking as well as low spoilage rate when added with 0.5 to 1.0% ground plant matters of Angelica acutiloba. Consumer acceptability evaluation showed a significant preference when added 0.5 to 1.0% ground leaves and stems of Angelica acutiloba into breads. Functional breads which added powder of Angelica acutiloba inhibited the growth of fungi. The more addition of Angelica acutiloba powder, the higher the degrees of this inhibited. These results suggested that the shelf-lives of the breads were extended by the addition of Angelica acutiloba powder. Further studies were required for improvement of functionality and diversity of bread products using medicinal plant materials as an additive.

• The Korean Journal of Food And Nutrition
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• v.27 no.5
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• pp.881-887
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• 2014

To prolong the shelf-life of domestic peaches, samples were treated with 30 ppm of aqueous chlorine dioxide ($ClO_2$) for 0~15 minute, after which the spoilage rate, changes in physico-chemical and sensory properties of treated samples were investigated. The control showed spoilage at day 4, and then 31.25% of control showed spoilage at day 8. However, samples treated with aqueous $ClO_2$ had no spoilage at day 4. On day 6, only 6.25% of samples treated with aqueous $ClO_2$ for 5 min showed spoilage. After 8 days, no spoilage was observed for samples treated with aqueous $ClO_2$ for 10 and 15 min. The weight change of the control was higher than that of aqueous $ClO_2$ treated samples for 8 days of storage. There were no differences in pH of samples among the treatments, but they were increased by storage time. Although there were no initial differences in the firmness of samples among the treatments, firmness of the control sample was decreased faster than those of the aqueous $ClO_2$ treated samples for 8 days of storage. No significant changes in lightness, redness and yellowness of the samples by aqueous $ClO_2$ treatment were observed during storage. The sensory parameters including taste, flavor, color, texture and overall acceptance at the initial period were not different among treatments. However, all scores of the control were decreased faster than those of aqueous $ClO_2$ treated samples during storage.

• Korean Journal of Poultry Science
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• v.17 no.2
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• pp.115-122
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• 1990

Effects of 7.5% potassium sorbate and/or 1% ascorbic acid dip on she]f-life of chicken parts stored at $4^{\circ}C$ was investigated. There was no remarkable difference in the microbial growth between 1% ascorbic acid dipped chicken parts and untreated chicken parts. Off-odor developed after 8 days storage and bacterial spoilage was occurred after 12 days storage. 7.5% potassium sorbate dip significantly retarded mesophilic and psychrotrophic counts compared with untreated, markedly reduced growth rate of Enterobacteriaceae. Fecal coliforms were not detected and bacterial spoilage was not occurred until 21 days storage. off-odor developed after 19 days storage and color was not significantly deteriorated until 21 days storage. Additional effect of 7.5% potassium sorbate and 1% ascorbic acid dip was found on retarded mesophilic, psychrotrophic and Enterobacteriaceae counts compared with 7.5% potassium sorbate dip alone. Bacterial spoilage was not occurred until 21 days storage. off-odor developed after 21 days storage and color was not significantly deteriorated until 21 dayss storage.

• The Korean Journal of Food And Nutrition
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• v.26 no.4
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• pp.731-736
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• 2013

To improve their shelf-life, domestic peaches were treated with hot air($46^{\circ}C$) for 0~9 hour, and the spoilage rate, changes of physico-chemical and sensory properties were investigated. The control showed spoilage at day 4, and then 50% of control showed spoilage on day 6. However, 12.5% of samples treated with hot air($46^{\circ}C$) for 6 hr showed spoilage on day 4. After 6 days, the spoilage rates of peaches treated with hot air treated for 3~9 hr were 16.7, 25.0, and 25.0%, respectively. Weight change of control was higher than that of hot air-treated samples for 6 days storage. There were no differences in pH of samples among the treatments, but pH increased with storage time. Hardness of hot air-treated samples was higher than that of control in the initial stage of storage. And then hardness of control sample was decreased faster than that of the hot air-treated samples for 6 days of storage. No significant changes in lightness and redness of the samples were observed after hot air treatment. Changes in yellowness of control occurred faster than that of hot air-treated samples during storage. The sensory parameters including taste, flavor, color, texture and overall acceptance at initial period were not different among treatments. The scores for taste, flavor, texture and overall acceptance of control decreased faster than those of hot airtreated samples during storage.

• Journal of Environmental Health Sciences
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• v.7 no.1
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• pp.51-57
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• 1981

This Study was carried out to investigate yeast and mold contamination in fermented milk products produced by 9 different domestic manufacturers from October 20. to December 5. 1980 The results obtained in the study were as follows 1) pH values of the products were ranged from pH 3.14 to pH 4.20 and average of sour milk drinks was pH $3.66\pm 0.19$ and fermented milks pH $3.74\pm 0.11$. Therefore the difference of pH average among sour milk drinks and fermented milks was statistically significant. (p<0.01) 2) In case of yeast contamination, yeast was found on all the four producted at the same date. From this result, it seemed that yeast contamination occured during the manufacturing progress. 3) Degree of contamination by the indicator organisms was E. coli positive, 3.7%: over 1,000 yeasts/ml, 14.8% over 10 molds/ml, 0.9%. 4) In the range of over 1,000 yeasts/ml, degree of contamination by yeast was 8.4% in fermented milk and 16.7% in sour milk drink. 5) Yeasts in product C increased to the spoilage number within 5 days and in H increased within 10 days at 5C. At 15$\circ$C, yeast increased to the spoilage number within 15 days in product A.D. 6) It seems that the yeast number of initial contamination should be important than the increase rate as criteria on the fermented Milk products.

• Journal of Microbiology and Biotechnology
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• v.33 no.4
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• pp.419-429
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• 2023

Ultraviolet C (UV-C, 200-280 nm) light has germicidal properties that inactivate a wide range of pathogenic and spoilage microorganisms. UV-C has been extensively studied as an alternative to thermal decontamination of fruit juices. Recent studies suggest that the efficacy of UV-C irradiation in reducing microorganisms in fruit juices is greatly dependent on the characteristics of the target microorganisms, juice matrices, and parameters of the UV-C treatment procedure, such as equipment and processing. Based on evidence from recent studies, this review describes how the characteristics of target microorganisms (e.g., type of microorganism/strain, acid adaptation, physiological states, single/composite inoculum, spore, etc.) and fruit juice matrices (e.g., UV absorbance, UV transmittance, turbidity, soluble solid content, pH, color, etc.) affect the efficacy of UV-C. We also discuss the influences on UV-C treatment efficacy of parameters, including UV-C light source, reactor conditions (e.g., continuous/batch, size, thickness, volume, diameter, outer case, configuration/arrangement), pumping/flow system conditions (e.g., sample flow rate and pattern, sample residence time, number of cycles), homogenization conditions (e.g., continuous flow/recirculation, stirring, mixing), and cleaning capability of the reactor. The collective facts indicate the immense potential of UV-C irradiation in the fruit juice industry. Existing drawbacks need to be addressed in future studies before the technique is applicable at the industrial scale.

• Food Science and Preservation
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• v.6 no.3
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• pp.264-269
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• 1999

The effects of film thickness and moisture absorbing materials(MAM) on the ginger qualities were investigated during MA storage for 150 days. LDPE films of 0.04, 0.06 and 0.08mm thicknesses were applied to select the adequate film in gas permiability. MAMs of sheet and sachet type were applied to 0.06mm-LDPE film bag to prevent moisture condensation during storage. Thickness of film used affected neither weight loss nor firmness of gingers during U storage. But the thinner in thickness showed the less changes in sprouting, spoilage and reducing sugar. Moreover, compared with MAP alone, MAPs with MAM of both sachet and sheet styles led to the weight loss of gingers increasing by more than 3-4 times, but sprouting rate, spoilage rate and reducing sugar decreasing by 3.3, 1.4 and 2.3 times, respectively. These results showed that MAP with UM was significantly effective to prolong the freshness of ginger by longer than 2 times, compared with MAP alone.

• The Korean Journal of Food And Nutrition
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• v.26 no.1
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• pp.85-91
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• 2013

For shelf-life improvement of the domestic peach, a treatment with low dose UV-C (0~3.0 $kJ/m^2$) irradiation was performed and the spoilage rate and changes of physico-chemical and sensory properties of the peach were investigated. Control showed spoilage at day 4, and then 50% of control showed spoilage at day 8. However, samples treated with low dose UV-C showed lower percentage of spoilage than those of control at day 8. Weight changes of control and the samples with UV-C treatment showed no difference during the storage period. There was no difference in pH of samples among the treatments but they were increased by storage time. Hardness of samples was not different among treatments at initial stage of storage after UV-C treatment. However, the hardness of control sample was decreased faster than those of the samples with low dose UV-C treatment after 6 days of storage. No significant changes in lightness, redness and yellowness of the samples by UV-C treatment were observed. The sensory parameters including taste, flavor, and color at initial and during storage period were not different among treatments except for texture and overall acceptance. The scores for texture and overall acceptance of control were decreased faster than those of UV-C treatments during storage. In general, samples treated with low dose UV-C showed higher sensory quality than control.