• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1523-1528
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• 1999

The consumer's demands for minimally processed fruits and vegetables have been increased rapidly because of its convenient handling, fresh-like quality as well as producing less wastes from the environmental point of view. Asian pears which are one of the main fruits widely produced and consumed in Korea easily lost their characteristics due to browning and softening after cutting. The objective of this study is to investigate the effects of various treatments on delaying deterioration of sliced Asian pears. 'Shingo' pear slices were treated with various solutions $(1%\;NaCl,\;0.2%\;L-cysteine,\;1%\;CaCl_2\;or\;1%\;calcium\;lactate)$ and were packaged with low density polyethylene $(LDPE,\;60\;{\mu}m)$, ceramic $(CE,\;60\;{\mu}m)$ or vacuum $(Ny/PE,\;80\;{\mu}m)$ film at $20^{\circ}C\;and\;0^{\circ}C$. In order to evaluate the quality of packaged sliced pears, quality index was determined in terms of color, firmness, soluble solids, titratable acidity. ascorbic acid, changes of gas composition, microbial test, and sensory quality. The results showed that sliced 'Shingo' pears packaged with CE and vacuum film maintained better quality than with LDPE at $0^{\circ}C\;and\;20^{\circ}C$. To retard browning and softening. 0.2% L-cysteine and 1% NaCl solutions applied for 1 minute were effective to reduce surface browning of sliced pears, and 1% $CaCl_2$ was the most effective to prevent softening.

• Horticultural Science & Technology
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• v.19 no.4
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• pp.521-525
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• 2001

This study investigated the effects of conventional predrying and modified atmosphere (MA) on the head quality and storability of Chinese cabbage 'Norang' cultivar. Immediately after harvest, heads were predried for 2 days and MA stored in $50{\mu}m$ PE film packages at $4^{\circ}C$. MA packaging restrained Hunter L and b values of Chinese cabbage more effectively than non-packaging during storage at $4^{\circ}C$. But there was little change between the two treatments. Fresh weight decreased less in heads treated with predrying and MA than non-treatment during storage. Predried Chinese cabbage heads kept a high level of soluble solids in 4 weeks of storage, while non-packaging maintained high contents of soluble solids for 6 weeks of storage period. Chinese cabbage heads contained 7.0 mg/gFW glucose, 6.3 mg/gFW fructose, and 0.6 mg/gFW sucrose as major soluble sugars at harvest. The content of sugars decreased immediately after predrying and increased steadily after 2 weeks storage. It was found inappropriate to assess head quality of Chinese cabbage by investigating was investigated by Hunter a, firmness, dry matters content, pH, and soluble sugars after predrying and MA package. Marketability of Chinese cabbage was lost when heads were stored at room temperature in 2 weeks. It showed poor appearance of heads stored at $4^{\circ}C$ in 7 weeks. Decay occurred in Chinese cabbage stored in MA under excessive relative humidity. Predried head showed good appearance during storage at $4^{\circ}C$ for 7 weeks. As a result, Chinese cabbage heads can be successfully stored for at least 7 weeks with predrying and MA storage.

• Korean Journal of Agricultural Science
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• v.41 no.4
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• pp.415-424
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• 2014

This study was carried out to determine the effect of storage condition, such as temperature or relative humidity (RH) in home-style refrigerator, on the change of quality traits and storage characteristics of Hanwoo M. longissimus to find out the condition for prolongation of shelf-life with maintaining the meat quality for consumers. Samples were sliced in $1{\pm}0.2cm$ thickness, and packed in foamed polystyrene tray with linear low-density polyethylene (LLD-PE) film to simulate the pre-packed Hanwoo loin sold in retail market, then stored in home-style refrigerator ($5^{\circ}C$/17% RH, Control), and chambers of $5^{\circ}C$/55% RH (T1), $5^{\circ}C$/85% RH (T2), and $-1^{\circ}C$/99% RH (T3), respectively. Quality traits (color, pH, water holding capacity, shear force and grilling loss) and storage characteristics (thiobarbituric acid reactive substances, volatile basic nitrogen and total microbes) were measured at 1, 4, 7, 14 and 21 days after storage. Lightness of Hanwoo loin stored in T1, T2 and T3 were higher than that of control until 14 days of storage, however at the end of storage (21 days) control showed significantly higher than other treatments (p<0.05). Redness and Yellowness of Hanwoo loin samples stored in T1 and T3 were significantly higher than others during all storage period (p<0.05). The water holding capacity (WHC) of control was significantly higher than others until 14 days of storage (p<0.05), however, Hanwoo loin stored in T2 was the highest ($63.64{\pm}7.62kg/cm^2$) at 21 days of storage. Hanwoo loin stored in T1 showed significantly lower shear force than others during all storage period (p<0.05). There was no consistent tendency in pH and grilling loss during storage in all treatments. Hanwoo loin stored in T1 showed lower TBARS value than others during storage period, however there was a rapid increase to $0.34{\pm}0.27mg$ malonaldehyde/kg meat at 21 days of storage. And, all the treated samples (from T1 to T3) showed significantly lower VBN values at 21 days of storage (p<0.05). The population of total aerobic microbes were significantly increased in all treatments as storage period increasing, and the population of T3 ($2.28{\pm}0.57logCFU/g$) was the lowest at 21 days of storage (p<0.05). From those results, it could be predicted the better storage condition to maintain the meat quality and prolong the shelf-life of Hanwoo loin by lowering the temperature and adjusting the humidity about 55%.

• Korean Journal of Agricultural Science
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• v.42 no.1
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• pp.37-46
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• 2015

This study was carried out to determine the effect of storage condition, such as temperature and relative humidity (RH), on the change of sensory properties and free fatty acid composition of pre-packed Hanwoo loin (Musculus longissimus) until $21^{st}$ day of storage. The Hanwoo loin was sliced in $1.0{\pm}0.2cm$ thickness and each of the sliced pieces was packed in a foamed polystyrene tray with linear low-density polyethylene (LLD-PE) film to simulate the pre-packed Hanwoo loin sold in retail market, then stored in home-style refrigerator (Con; $5^{\circ}C$, 17%RH), and temperature and RH controled chambers (T1; $5^{\circ}C$, 55%RH, T2; $5^{\circ}C$, 85%RH, and T3; $-1^{\circ}C$, 99%RH), respectively. The sensory characteristics of pre-packed Hanwoo loin during storage in different conditions were measured on raw or after cooking. After 21 days of storage, the loin stored in T3 showed significantly high color and acceptability scores ($7.46{\pm}1.07$, $7.06{\pm}1.36$, respectively) on raw loin, and flavor and acceptability scores ($7.16{\pm}0.90$, $6.90{\pm}0.92$, respectively) on cooked loin than those of others (p<0.05). The concentration of 12 fatty acids of pre-packed Hanwoo loin during storage in different conditions were analysed. The concentration of oleic acid (C18:1, $39.92{\pm}3.22%$), palmitic acid (C16:0, $28.20{\pm}2.42%$), and stearic acid (C18:0, $12.59{\pm}2.79%$) was high in Hanwoo loin on $1^{st}$ day of storage. The concentration of palmitic acid of Hanwoo loin stored in T2 was increased significantly after $4^{th}$ day of storage (p<0.05), and the concentration of myristic acid(C14:0) of Hanwoo loin stored in treated chamber (T1 to T3) was significantly higher than Con after $14^{th}$ day of storage (p<0.05). The concentration of linolenic acid (C18:3) of Hanwoo loin was decreased significantly after $4^{th}$ day of storage in all tested storage conditions (p<0.05). However, there was no significant or consistent change in the concentration of oleic acid (C18:1) during storage period in every Hanwoo loin stored in tested conditions. Although, the concentration of total monounsaturated fatty acids (MUFA) was decreased in Con and T2 (p<0.05), there was no consistent change in the monounsaturated fatty acids to saturated fatty acids ratio (MUFA/SFA) during storage period (p>0.05). From those results, it was considered that storage condition affects on the sensory acceptability and fatty acid composition of pre-packed Hanwoo loin as storage period was increased.

• Applied Chemistry for Engineering
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• v.17 no.3
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• pp.243-249
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• 2006

Porous polymer gel electrolytes (PGEs) based on poly(vinylidenefluoride-co-hexafluoropropylene) (P(VdF-co-HFP)) as a polymer matrix and polyvinylpyrolidone (PVP) as a pore-forming agent were prepared and electrochemical properties were investigated for an electric double layer capacitor (EDLC) in order to increase a permeability of an electrolyte into the PGE. Propylene carbonate (PC) and ethylene carbonate (EC) as plasticizers, and tetraethylammonium tetrafluoroborate ($TEABF_4$) as a supporting salt for the PGE were used. EDLC unit cells were assembled with the PGE and electrode comprising BP-20 and MSP-20 as activated carbon powders, Super P as a conducting agent, and P(VdF-co-HFP)/PVP as a mixed binder. Ion conductivity of PGEs increased with an increased PVP content and was the best at 7 wt% PVP, whereas electrochemical characteristics such as AC-ESR of unit cell were better in 3 wt%. And electrochemical characteristics of the unit cell with PGE were the best at a 33 : 33 weight ratio of PC to EC. Specific capacitance of a mixed plasticizer system of PE and EC was higher than that of pure PC. Ion conductivity of PGEs with a film thickness of $20{\mu}m$ was higher, but electrochemical characteristics of unit cells were higher for a $50{\mu}m$ membrane thickness. Also, the unit cell has shown the highest capacitance of 31.41 F/g and more stable electrochemical performance when PGE and electrode were hot pressed. Consequently, the optimum composition ratio of PGE for EDLCs was 23 : 66 : 11 wt% such as P(VdF-co-HFP) : PVP = 20 : 3 wt% and PC : EC = 44 : 22 wt%. In this case, $3.17{\times}10^{-3}S/cm$ of ion conductivity was achieved at the $50{\mu}m$ thickness of PGE for EDLCs. And the electrochemical characteristics of unit cells were $2.69{\Omega}$ of DC-ESR, 28 F/g of specific capacitance, and 100% of coulombic efficiency.