• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.6
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• pp.735-739
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• 2019

The purpose of this study was to measure pH, trimethylamine (TMA), and total volatile basic nitrogen (TVB-N) as indicators of freshness during largehead hairtail Trichiurus lepturus storage, and to compare these indicators with those obtained by the sensory evaluation of quality index method (QIM) sensory evaluation. Largehead hairtail samples were stored at 4℃ and evaluated every 3 days until decay. The QIM sensory evaluation indicated scores of 0, 8.9, and 20 on storage days 0, 6, and 20, respectively. By day 15, the samples were completely decayed. The pH slowly increased during the storage period, reaching a maximum of 7.4. In the day 6, TMA and TVB-N contents were 2.97 and 15.57 mg/100 g, respectively. Thus, at 4℃, the largehead hairtail starts to decay after 6 days and, after 9 days, cannot be consumed safely

• Journal of Biosystems Engineering
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• v.33 no.4
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• pp.239-247
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• 2008

Firmness is very important factor to evaluate the freshness and ripeness among the various factors, in concerning about the melon quality. This study was carried out to develop the technique using impact signal to measure the melon firmness nondestructively. Results of analyzing impulse signals of melons having different firmness levels showed that the firmness of melon affected various impulse responses including amplitude, transmitted time, maximum peak frequency, firmness index 1 ($f^2m$), and firmness index 2 ($f^2m^{2/3}$). Impulse signal amplitude was the best indicator to predict the firmness of melon because of a strong corelation ($R^2\;=\;0.9071$). Firmness index 1, firmness index 2, maximum peak frequency, and normalized transmitted time were also possible indicators with acceptable correlation values.

• Food Science and Preservation
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• v.24 no.2
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• pp.159-167
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• 2017

This study was investigated the effects of maintaining the freshness and stabilization of supply and demand for lettuce (Lactuca sativa L.) by packaging methods in summer. Post-harvest lettuces were packaged by corrugated box, polypropylene (P) box, and individual wrapping using polyvinyl chloride (PVC) film. Then, the lettuce samples were stored at $2^{\circ}C$ and evaluated the change of quality during storage. The lettuces wrapped individually with PVC film had lower weight loss rate, color change, and browning index compared to lettuces packaged by corrugated box and P box. The SPAD value and hardness were higher in lettuces wrapped individually with PVC film than other packaging methods. The lettuces wrapped individually with PVC film were showed the highest total phenolic contents and DPPH radical scavenging activity, but there were no significantly differences by packaging methods. The lettuces packaged by corrugated box were showed the inside browning after 14 days. However, the lettuces wrapped individually with PVC film were showed the best appearance. Therefore, the packaging method of wrapped individually with PVC film were effective in maintaining the freshness during 21 days and helpful for the stabilization of supply and demand for lettuce in summer.

• Fisheries and Aquatic Sciences
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• v.17 no.2
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• pp.189-195
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• 2014

Headspace volatile compounds of cold-stored and freeze-dried Krill Eupausia superba were analyzed to investigate their flavor qualities using a system combining a dynamic headspace isolator, an automatic thermal desorber, and a gas chromatograph-mass-selective detector. Levels of oxidation products of polyunsaturated fatty acids such as aldehydes, alcohols, and ketones, which are known to give seafood a nasty smell because of their low flavor threshold values, increased during cold storage of krill. Notably, levels of 2-methylpropanal, 3-methylbutanal, 2-methylbutanal and 2-butanone increased during its storage. They can be considered index compounds of off-odor according to freshness degradation during storage. By contrast, in freeze-dried krill powder, levels of aldehydes, ketones, and aromatic compounds decreased rapidly. Only alcohols, which did not greatly affect the food flavor, were isolated in large amounts. It was confirmed that levels of oxidized compounds of krill increased during cold storage, but decreased in freeze-dried krill.

• Food Science and Preservation
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• v.4 no.2
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• pp.131-137
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• 1997

Effect of storage on the tree and quality of early cultivar of Citrus unshiu Marc. produced in Cheju according to harvest time were investigated. Soluble solids, acid content, flesh ratio, firmness and specific cavity of the fruits harvested at 27th of November were 12.0, 1.03%, 79.98%, 0.774kg-force, 0.912, respectively. Soluble solids, total sugar and reducing sugar were increased gradually, but acid content was decreased slightly as delayed in harvest time. Otherwise specific gravity and firmness were not shown in great during harvest time, color index(a/b) was increased sharply till late November and then remained in stationary phase. On these result, we recommend that the harvest time of early cultivar of Citrus unshiu Marc. would be during December because of wilting partly. Fully ripened-fruits harvested late, compared to ordinary harvest time, with cold storage would be kept more quality and freshness of fruits for fresh consumption than the fruits harvested early and stored at room temperature.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.23 no.3
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• pp.163-171
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• 2017

Effects of different packaging methods for maintaining the shelf life and postharvest quality of iceberg lettuce (Lactuca sativa L.) were studied after harvesting in summer season. Lettuce heads were packaged in plastic crate with or without different films such as (A) Individual lettuce head sealed packaging with linear low density polyethylene (LLDPE) film; (B) Packaging lettuce head in plastic crate and wrapped with LLDPE film; (C): Individual lettuce head sealed packaging with perforated high density polyethylene (HDPE) film; (D) Packaging lettuce head in plastic crate and wrapped with perforated HDPE; and (E) Packaging lettuce head in plastic crate without any film (control), and stored at $2^{\circ}C$ for 35 days. Several quality parameters such as fresh weight loss, SPAD (soil & plant analyzer development) meter value, respiration rate, moisture content and appearance of lettuce were investigated. The lettuce wrapped with individually-sealed LLDPE film showed the lowest weight loss and the highest SPAD value rendering the best appearance index among the treataments throughout the three-week storage period at $2^{\circ}C$. Extending the freshness of iceberg lettuce during low temperature storage will definitely increase the salability potential in the domestic market even during summer season.

• Horticultural Science & Technology
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• v.31 no.4
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• pp.429-436
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• 2013

Kimchi cabbage 'Choongwang' cultivar is mainly cultivated during summer in Gangneung area. 'Choongwang' cultivar was harvested in late July, applied with predrying, room cooling, and forced air cooling, and then packaged with/without 0.02 mm HDPE film to estimate the effect of postharvest treatment on quality characteristics (weight loss, trimming loss, firmness, SSC, color index, sensory evaluation) during 8 week storage at $2^{\circ}C$. Kimchi cabbage without 0.02 mm HDPE film showed high weight loss up to 13-20% while those of with liner were significantly lower. Also forced air cooling among the postharvest treatments was effective to reduce both weight loss and trimming loss. Appearance and freshness in sensory evaluation were the important factors in estimating good quality during storage. Liner treatment with forced air cooling showed highly significant for maintaining appearance and freshness ($P{\leq}0.01$). Color index was no differences between with/without 0.02 mm HDPE film and postharvest treatments. After 6 weeks storage in without 0.02 mm HDPE film with room cooling or control appearance was severely damaged and also internal browning was found. While in with 0.02 mm HDPE film internal browning was found after 8 weeks storage, just in room cooling or predrying treatment.

• Journal of Environmental Health Sciences
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• v.1 no.1
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• pp.9-13
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• 1974

For the purpose of determining the degree of freshness and bacterial contamiation of poultry farm eggs, the author collected 550 specimens from poultry farm, during the period from July 22 through October 3, 1973. Eggs of poultry farm were stored at $4{\pm} 1{\circ}$(Relative humidity 67~86%), $18\pm 1\circ$(70~80%) and $25\pm 1\circ$(73~82%) during 20 days. The results are summarized as follows: 1) Egg weight was decreased $0.97\pm 0.27$ gm at $4\pm 1\circ$, $1.68\pm 0.25$ gm at $18\pm 1\circ$ and $2.76\pm 0.30$ gm at $25\pm 1\circ$ after 20 days. 2) Specific gravity of fresh eggs was found to average 1.0785. 3) Yolk index of fresh eggs was found to average 0.419. 4) The regression equation between Yolk index and days was obtained y=0.417-0.001x (r=-0.481, p<0.05) at $4\pm 1\circ$, y=0.394-0.004 x (r=-0.738, p<0.01) at $18\pm 1\circ$ and y=0.391-0.011 x (r=-0.958, p<0.001) at $25\pm 1\circ$. 5) The regression equation between Yolk index and NaCl concentration (specific gravity) was obtained y=-0.001+0.04 x (r=0.796, p<0.001). 6) pH of albumin was changed from 8.0 to 8.8, 9.2 and 9.3 at $4\pm 1\circ$, $18\pm 1\circ$ and $25\pm 1\circ$ after 20 days. 7) Total Viable Bacteria in air cell was increased slowly according to the stored period at each temperature.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.8
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• pp.1278-1284
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• 2007

Changes in the concentrations of biogenic amines (BAs) in fresh beef, pork, and chicken breast and leg were investigated during storage, and the relationship between the content of volatile basic nitrogen (VBN) and BAs was evaluated. As the storage period increased, the levels of putrescine (PUT), cadaverine (CAD) and tyramine (TYM) increased in all the meat samples, except for TYM in beef (p<0.001). The level of BAs in beef, pork and chicken changed but the extent of these changes was different among the kinds of BAs and meats. Measurement of the VBN content was confirmed as a good index for interpreting the specific BAs content in general, such as PUT, CAD, and TYM, as well as evaluating a meat's freshness during storage. However, the kinds of BAs which can be predicted from the VBN content varied in different meats (p<0.05).

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.27 no.2
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• pp.115-121
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• 2021

The evaluation of package temperature for fresh preservation of cucumber was investigated. The fresh cucumber is available in markets of Korea during whole seasons, for the help of farmer, distributor and consumer. Cucumbers were stored within cardboard boxes packaging covered with low density polyethylene (LDPE) at different temperatures (5, 10, 15 and 20℃). Changes in weight loss, hue angle, firmness, moisture content and general appearance (shape of cucumber) were investigated during storage of cucumbers. General appearance index with non-packaging decreased more than with LDPE film packaging at 5℃ and 10℃. During storage of cucumbers, general appearance index as freshness showed packaging effect at low temperature than room temperature. In the fresh weight loss, the packaged cucumbers were less reduced than that of the non-packaging ones. At color change, Hue angle of cucumber stored within low temperature with film packaging decreased gradually during storage. However remarkable change in hue angle were observed in cucumber within LDPE film packaging treatments of 15℃ and 20℃ storage. The effect of hue angle with packaging appears differently depending on the storage temperature conditions. The firmness and moisture content of cucumber flesh were not affected by packaging and storage temperature. In this experiment, cucumbers packaged with LDPE film at 5℃ and 10℃ were the most desirable for extending the quality. These results suggest that packaging of low temperature treatments in combination could be effective in prolonging the shelf life of cucumber.