• Food Science and Preservation
• /
• v.10 no.2
• /
• pp.131-135
• /
• 2003

Bell pepper was packed with several plastic films, and investigated the quality Characteristics such as gas composition, weight loss, microbial load, soluble solid content, ascorbic acid and color during storage at 10$^{\circ}C$. Cast polypropylene (CPP), low density Polyethylene (LDPE), Polyolefin (MPD, PD961) and linear low density polyethylene (LLDPE) were used for this purpose. Oxygen concentration inside packages generally showed a 10∼14% after 1∼2 weeks, but package with CPP maintained above 15％ throughout the storage. Carbon dioxide concentration of CPP was above 2%, but other treatments showed below 2%. Weight loss of all treatments was below 3.0% after 5 weeks. Total microbial count showed a similar pattern compared to yeast and mold, and CPP maintained the highest microbial load after 3 weeks. Yellowness (b value) of bell pepper was generally increased throughout the storage, and MPD and PD961 were higher than other treatments.

• Korean Journal of Food Science and Technology
• /
• v.38 no.2
• /
• pp.183-187
• /
• 2006

Surface browning, caused by cutting and other wound during minimal processing, is very important quality criterion to consumers. Shelf-life of fresh-cut potatoes was extended using natural antibrowning treatments. Fresh-cut potatoes dipped with licorice and green tea extracts were packed with LDPE film and stored at $4^{\circ}C$ for 14 days. Quality characteristics of fresh-cut potatoes were investigated during storage. During storage, L value decreased and PPO activity increased. PPO showed the lowest activity at around 7 days storage, during which browning was effectively inhibited in licorice- and green tea extract-treated potatoes. Total phenol and chlorogenic acid contents increased for 7 days. Results suggest natural licorice extracts with ascorbic acids are effective antibrowning agents for maintaining quality of fresh-cut potatoes.

• Korean Journal of Food Science and Technology
• /
• v.34 no.6
• /
• pp.1018-1022
• /
• 2002

Effect of nitric oxide (NO) treatment on physiology and quality characteristics of peaches (Prunus persica L. Batsch) was determined. Peaches were treated for 4 hr with NO (0, 10, 100 ppm) gas under oxygen-free atmosphere at $10^{\circ}C$, packaged with 0.05-mm LDPE film, and stored at $10^{\circ}C$ for 15 days. Treatment with 100 ppm NO reduced the ethylene production and the loss of flesh firmness in peaches, but did not affect soluble solids, titratable acidity, and surface color. Oxygen-free atmosphere induced the reduction of respiration rate and ethylene production. Modified atmosphere packaging retarded the loss of flesh firmness and surface greenness, but decreased soluble solids and titratable acidity regardless of NO treatment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1996.11a
• /
• pp.82-85
• /
• 1996

It is considered that the effect of radiation aging, such as electron beam due to the ultra-high voltage for transmission, on the physical properties and electrical characteristics of electrital insulating materials. Low-density polyethylene(thickness 100[${\mu}{\textrm}{m}$]) is selected as an experimental specimen. Fourier transform infra-red spectrum, X-ray diffraction, differential scanning calorimetry and scanning electron microscopy is used so as to analysis the physical properties, the morphological changes and the crystallinity of LDPE. And it is made an experiments of dielectric characteristics in the temperature range of 20[$^{\circ}C$]~120[$^{\circ}C$], in the frequency range of 30[Hz]~1.5$\times$10$^{5}$ [Hz] and in the applied voltage range of 300[mV]~1500[mV].

• Food Science and Preservation
• /
• v.7 no.1
• /
• pp.8-11
• /
• 2000

The antimicrobial extracts of rheum palmatum and coptis chinensis root as well as grapefruit seed extract(GFSE) were applied to dipping treatment for keeping qualities of cucumbers, respectively, which were then packed in low density polyethylene(LDPE) films incorporated with 1 % antimicrobial extracts and stored $10^{\circ}C$. Dipping and packaging in the antimicrobial agents suppressed the growth of putrefactive microorgani는 and the decay ratio of cucumbers. In addition, the loss ratio of ascortic acid content and their weight was decreased during the sotrage of cucumbers. Consequently, the combined method of dippinf and packaging in antimicrobial agents turned out to be superior to dipping treatment or film-packaging in the view point of decay ratio and the keeping qualities of cucumbers.

• Food Science and Preservation
• /
• v.16 no.6
• /
• pp.817-823
• /
• 2009

We investigated the effects of storage temperature and packaging treatment on the freshness of high-quality 'Fuji' apples to improve consumer confidence in the maintenance of high fruit quality during distribution. A 0.35 mm-deep PET tray form-sealed with a 0.05 mm LDPE film lid was developed and tested with the aim of optimizing gas composition within the package headspace to utilize potential modified atmosphere (MA) storage to maintain the freshness of apples. Weight loss, color difference, firmness, respiration rate, gas concentrations in packages, acidity, solid soluble content, and fruit decay rate were measured during storage at $5^{\circ}C$ and $25^{\circ}C$. The results showed that respiration rate, weight loss, color difference, and firmness were lower and overall quality better during storage at $5^{\circ}C$ compared with $25^{\circ}C$. Also, the fruits packed in the functional tray form showed a low level of quality changes compared with the control (no packaging). The accumulated gasconcentrations in the headspace of the packages decreased from 21% to 12% $O_2$ and increased from 0% to 5% $CO_2$ (v/v) on day 7, and after remained at those levels thereafter. Soluble solid contents and total acidities of the packaged fruits were in the range of $11\;-\;14^{\circ}Brix$ and 0.2 0.3% during storage. Decay rates in the control and packaged fruits were more than 20% and less than 10% at 3 weeks, respectively. Based on the standard acceptable level (less than 10%) of total weight loss, it could be estimated that the shelf life of top-quality fruits packed in functional trays was 3 weeks at $5^{\circ}C$ and 16 weeks at $25^{\circ}C$, whereas the shelf life of the control fruit was 1 week and 12 weeks, respectively. For the top-quality fruit "Fuji" apples, the best results were obtained with a functional tray form for packaging treatment and a storage temperature of $5^{\circ}C$.

• Journal of Biosystems Engineering
• /
• v.41 no.2
• /
• pp.98-107
• /
• 2016

Purpose: The aim of this study was to find an appropriate polymer film, which could reduce the water condensation for pallet-size modified atmosphere packaging (MAP). Methods: Five different types of films were selected from several commercialized films. Prior to the real food storage test, plastic boxes with wetted plastic balls were used to simulate the high humidity conditions of real food storage. The initial MAP condition was 5% oxygen and 95% nitrogen, and the $O_2$ concentration, the relative humidity and water condensation inside the films were checked on a daily basis. The MAP test for tomatoes was conducted by using the most appropriate film from the five films examined in this study. Results: Every film except Mosspack(R) indicated a similar variation in the $O_2$ concentration over the course of time. The relative humidity near the surfaces of all the films except nylon-6 approached saturation conditions over time. For three kinds of films, namely, low-density polyethylene (LDPE) film, anti-fogging oriented polypropylene (AFOPP) film, and Mosspack(R), the inner surfaces of the films were fully covered with dew after a storage period of a day. Conversely, an area of 4.5% was covered with dew in the case of the poly lactic acid (PLA) film, and there was no dew inside the nylon-6 film. The pallet-size MAP test for tomatoes was conducted by using the nylon-6 film and there was no water condensation inside the nylon-6 film over three weeks of storage. Conclusions: During the pallet scale MAP, water condensation could cause severe fungal infection and wetting of the corrugated box. Hence, it was important to minimize water condensation. This study showed that the MAP films with high WVTR such as nylon-6 and PLA could reduce the water condensation inside the pallet scale MAP.

• Korean Journal of Food Science and Technology
• /
• v.37 no.6
• /
• pp.933-938
• /
• 2005

To investigate pertinent packaging treatment of fresh-cut potatoes (Solanum tuberosum L.), potato cubes were subjected to passive, gas exchange, and vacuum packaging conditions. Low density polyethylene film (LDPE), polypropylene film (PP), anti-fogging film (AP), and perforated film (PF) were used as passive packaging treatments. Mixed gases of 5% $CO_2/5%\;O_2$ (MA1) and 10% $CO_2/5%\;O_2$ (MA2) were applied as gas exchange packaging. Packs filled with cubes were kept at $5^{\circ}C$, and changes in weight loss, surface color, vitamin C content and sensory quality of cubes were analyzed during storage. Respiration rate of cubes was 2.11 times higher than that of intact raw potatoes at $5^{\circ}C$. Gas concentrations in passive packaging was maintained at 1-2% $O_2$ and 4-14% $CO_2$ after 7 days. Gas levels changed depending on films used. Cubes packed in PP and MA2 showed lowest weight loss and browning during storage. Firmness of cubes was not affected by packaging treatment. Vitamin C content was highest in cubes packed with AF. Cubes packed in MA2 showed highest quality upto 10days storage, followed by those packed in PP and AF.

• Food Science and Preservation
• /
• v.23 no.4
• /
• pp.479-487
• /
• 2016

This study was conducted to investigate the effect of 1-methylcyclopropene (1-MCP) and ethylene-absorbent on the qualities of Prunus mume fruit. Prunus mume fruits were stored without film packaging (Cont), packed in LDPE film (Cont-P), and packed with ethylene-absorbent (Cont-PE). Fruits were treated with 1-MCP (1 ppm) for 24 hr at $1^{\circ}C$. After treatment, fruits were packed in LDPE film (MCP-P) and with ethylene-absorbent (MCP-PE) and then stored at $1^{\circ}C$ for 8 weeks. Total soluble solids increased during storage but decreased after 6 weeks while total acidity decreased during storage. Cont was almost completely decayed after 8 weeks of storage while Cont-P, Cont-PE, MCP-PE, and MCP-P were 46, 69, 83, and 5% decayed, respectively. L value decreased but a value increased during storage in all samples. Firmness of peel and flesh of samples decreased gradually for 8 weeks. Respiration rate did not show any significant difference among samples. Ethylene production of Cont showed $0.05{\mu}L/kg/h$ but immediately after 1-MCP treatment, it showed $0.02{\mu}L/kg/h$. Oxalic and malic acids decreased while citric acid increased during storage; fructose and glucose substantially decreased after 8 weeks whereas sorbitol and sucrose increased upto 4 weeks and then decreased thereafter. Based on these results, packing the fruits treated with 1-MCP could extend the freshness of Prunus mume fruit.

• Food Science and Preservation
• /
• v.16 no.2
• /
• pp.179-185
• /
• 2009

To develop an Enoki mushroom packaging method, mushrooms were stored at $1^{\circ}C$ for 12 days after passive MAP packaging(PM), vacuum packaging(VM), and gas flushing packaging(AM), after investigation of film thickness influences on respiration rates and gas compositions(LDPE films 20, 40, and 60 m in thickness were tested). Enoki mushrooms had respiration rates of 26.4 mL $CO_2/kg/hour$ at $0^{\circ}C$, 80.0 mL $CO_2/kg/hour$ at $10^{\circ}C$, 130.9 mL $CO_2/kg/hour$ at $20^{\circ}C$, and 130.9 mL $CO_2/kg/hour$ at $30^{\circ}C$. A film thickness of 20 m was chosen for further tests to maintain the oxygen concentration above the minimum growth level; the thinnest film offered a higher gas transmittance rate than did the thicker films. No anaerobic respiration was evident over 12 days of storage using any packaging method, with the exception of VM. AM, using a high concentration of $CO_2$, restricted respiration rate. Mushrooms packaged using the VM method showed the greatest weight loss and extent of discoloration among the packaging methods tested, followed by AM mushrooms using 50% $CO_2/10%\;O_2/40%\;N_2$. Mushrooms packaged by the VM and PM methods developed a serious off-flavor after 2 days of storage, and a high stipe elongation rate after 5 days of storage, respectively. However, AM using 50% $CO_2/10%\;O_2/40%\;N_2$ of various gas ratios tested, allowed Enoki mushrooms to be maintained for up to 12 days without development of off-flavor, discoloration, or moldiness.