• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.29 no.2
• /
• pp.111-118
• /
• 2023

In this study, the feasibility of laser patterning on the surface of food packaging polymer film was confirmed, and the surface patterning process conditions of femtosecond laser were established. In addition, it was proved that the surface properties of the film can be changed and controlled through the fabrication of various patterned films on the surface of food packaging films such as HDPE, PP, and PET. Various patterned surfaces, including large-scale circular patterns induced by a single femtosecond laser pulse, roughness patterns achieved by overlapping single pulses by 30%, straight line patterns, roughness patterns obtained by overlapping straight line patterns, and grid patterns formed by intersecting straight line patterns were fabricated. The characteristics of the patterned HDPE, PP, and PET films, based on the surface pattern structure and size, were analyzed using SEM, AFM, and contact angle measurements. Compared to the surface of each control film without femtosecond laser patterning, the contact angles of the surfaces of large-area circular patterning HDPE and PP films, large-area roughness patterning HDPE and PP films by overlapping 30% of single pulses, and large-area roughness patterning PET film by overlapping rectilinear patterning were in the range of 27.1-37.5 degree. This indicated that the HDPE, PP, and PET films became more hydrophilic after patterning. On the other hand, the HDPE film patterned with a large-scale grid pattern exhibited a contact angle of 120.4 degree, indicating that the HDPE film became more hydrophobic after patterning. Therefore, films that have been changed to hydrophilic surfaces through patterning can be used in anti-fouling applications where proteins, cells, viruses, and other food materials do not adhere or are easily detached. In addition, if a superhydrophobic surface of 150 degrees or more is fabricated through more precise lattice patterning in the future, it will be possible to use it for superhydrophobic surface applications such as self-cleaning.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.26 no.3
• /
• pp.133-138
• /
• 2020

As HMR (home meal replacement) food market grows rapidly, a new packaging with more HMR specialized functions is highly required to promote consumers' convenience. A susceptor is defined as a material generating heat by absorbing electromagnetic energy such typically as radiofrequency or microwave radiation. In microwave cooking, susceptors are made of conductive metal thin film deposited on paper or plastic sheet and have generally been used to help crispen or brown foods by converting microwave energy into heat. This mini review article deals with current status of microwave susceptor packaging including commercial products, technical theory, types of susceptor and a test method for heating performance.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.26 no.1
• /
• pp.19-23
• /
• 2020

Al-laminated packaging film incorporating ascorbic acid or tocopherol at inner food contact layer was tested in the potential to improve antioxidative preservation of powdered infant formula under CO₂-enriched atmosphere. Product of 200 g was packaged with the packaging film containing 0.3% antioxidant in sealant layer of low density polyethylene and stored at 30℃ for 286 days with periodic measurement of package atmosphere and product's quality attributes. The CO₂-flushed package resulted in shrinkage of tight contact between the product and the film not allowing gas sampling of package atmosphere after 140 days. Package of tocopherol-incorporated film allowed some ingress of oxygen after 112 days presumably due to its weakening of heat-seal area. The increased oxygen concentration in the tocopherol-added film package led to the concomitant increase of peroxide value, an index of lipid oxidation. On the other hand, packaging of ascorbic acid-added film pouch could suppress lipid oxidation marginally in consistent manner compared to control package without any antioxidant.

• Food Science and Biotechnology
• /
• v.15 no.5
• /
• pp.683-687
• /
• 2006

The respiration rate of Chinese quince was measured at 0, 5, 10, and $20^{\circ}C$ to determine its tolerable range of storage temperatures. Based on the measured respiration rates, plastic films covering a wide range of gas permeabilities were used for packaging and storing individual Chinese quince at 0 and $10^{\circ}C$. Chinese quince can be categorized as low respiration fruit. Higher respiratory quotients were observed at higher temperature suggesting that the tolerable temperature range for storage is $0-10^{\circ}C$. Packages containing Chinese quince wrapped in highly gas-permeable polyolefin film PD 941 attained, with progressive decreases in volume, 9.5-10.2% $O_2$ and 1.3-1.8% $CO_2$ at $0^{\circ}C$, 8.1% $O_2$ and 2.4% $CO_2$ at $10^{\circ}C$. At these levels, PD 941 could preserve the fruit at acceptable quality levels for 152 and 50 days at 0 and $10^{\circ}C$, respectively. Less gas-permeable packages built up high $CO_2$ concentrations (above 15.8%) and low $O_2$ concentrations (less than 1.8%) causing free volume expansion and eventual dark discoloration of the fruit. The storage life realized by packaging with polyolefin film PD 941 could facilitate the availability of Chinese quinces in winter and spring for medicinal or ornamental purposes in the fresh state.

• Food Science and Preservation
• /
• v.5 no.2
• /
• pp.154-161
• /
• 1998

Changes of free sugars and sugar alcohols of fresh shiitake were measured during storage. Shiitake were stored at 1$^{\circ}C$ and -4$^{\circ}C$, with non-packaging, wrapping, 0.03mm polyethylene(PE)film packaging(unpunched and punched, unprecooled and precooled before storage), 0.05mm PE film (vacuum packaging). Chanties of glycerol, arabitol and arabinose contents were not marked during storage. The content chanties of $\beta$-rhamnose, fructose, glucose, mannitol, sucrose and maltose were the smallest until 40days storage and were increased significantly after 40 days and then decreased significantly after 50days. Content of $\beta$-rhamnose during storage when was treated unprecooling, 0.03mm PE film punched and unpunched at -4$^{\circ}C$ was the highest 25.08% and 34.86%, respectively in 50~60days. Content of mannitol was not changed at -4$^{\circ}C$.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.8 no.2
• /
• pp.39-43
• /
• 2002

Increasing use of plastics in food packaging materials has led to the issue of food-plastic packaging materials's mutual interactions. Although the plastic packaging materials are generally considered as inert, migration and sorption of fatty materials are some of the problems associated with their use. So, this work investigated the compatibility of three structurally different polymers, polypropylene (PP), polyethyleneterephthalate (PET) and ethylene vinyl alcohol copolymer (EVOH) with some structurally different food fats. The main goal was to study the sorption of food fats by the plastic films and to see what extent mechanical properties of the plastic films was affected by plasticization effect due to sorption of fatty materials. PP, PET, and EVOH films was immersed in pure triglycerides, and then extracted with hexane and analyzed for the amounts of fat migrated. The sorbed films were also investigated for change in mechanical properties. Result showed that structural factor of the films and fatty materials plays important role in th migration process. The fat with the simplest structure are migrated more easily that the fat with more complex structure. However, structural effect of migration was varied according to degree of crystallinity and density of plastic films. In addition to that, polarity of plastic film was affected migration of fatty materials significantly. Additional research is needed to justify the reason why migration of fatty materials into the films was affected by polarity and structural integrity.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.11 no.2
• /
• pp.101-107
• /
• 2005

The term 'antimicrobial' packaging encompasses any packaging technique(s) used to control microbial growth in the food product. These include packaging materials and edible films and coatings that contain antimicrobial agents, and also techniques that modify the atmosphere within the package. In recent years, antimicrobial packaging has attracted much attention from the food industry because of the increase in consumer demand for minimally processed, preservative-free products. Reflecting this demand, the preservative agents must be applied to packaging in such a way that only low levels of preservatives come into contact with the food. The film or coating technique is considered to be more effective, although more complicated to apply. New antimicrobial packaging materials are being developed continually. Many of them exploit natural agents, to control common food-borne microorganisms. Current trends suggest that in due course, packaging will generally incorporate antimicrobial agents and the sealing systems will continue to improve. The focus of packaging in the past has been on the appearance, size and integrity of the package. A greater emphasis on safety features associated with the addition of antimicrobial agents is perhaps the next area for development in packaging technology.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.14 no.3
• /
• pp.229-234
• /
• 1985

The effect of packaging on the quality of dried anchovy was investigated, when packed with various materials and stored at different conditions. In cases of nitrogen gas substitution or addition of antioxidant, the reaction rates of lipid oxidation, the loss of available lysine and browning of the samples sealed in aluminum laminated film bag were lower than those packed in kraft paper or polyethylene film bag while the samples without gas substitution did not reveal any great differences in the rate of the reactions. The shelf-lives of the samples computed as a function of lipid oxidation were 90, 98 and 137 days at the storage of $35^{\circ}C$ for the packages of kraft paper, polyethylene and aluminum film respectively. And those at $55^{\circ}C$ storage for the same samples were 47, 51 and 77 days. The half-lives of available lysine loss were 227, 209 and 312 days at $35^{\circ}C$: 83, 83 and 147 days at $55^{\circ}C$ for the samples respectively. And the shelf-lives determined as a function of browning reaction were 26, 27 and 49 days at $55^{\circ}C$. The predicted shelf-lives at $25^{\circ}C$ as a function of lipid oxidation were 130, 140, and 189 days for kraft paper, polyethylene and aluminum laminated film packaging: 207, 229 and 246 days for the browning reaction, and 363, 339 and 415 days for the loss of available lysine. The results suggest that the protective effect of packaging on the reactions of lipid oxidation and browning could not be aided unless the air was expelled or replaced to inert gas.

• Food Science and Preservation
• /
• v.20 no.1
• /
• pp.7-13
• /
• 2013

Mushrooms have a shorter shelf-life than most vegetables because of their very high respiration rates, sensitivity to enzymatic browning and susceptibility to microbial spoilage. This study was conducted to investigate effects of various packaging materials and precooling on the quality of mushrooms (Agaricus bisporus). Mushrooms were precooled at $4^{\circ}C$ for three hours and packaged using the following packaging materials; 1) polyethylene (PE) film bags of 0.03 mm thickness, 2) polypropylene (PP) film bags of 0.03 mm thickness, and 3) polystyrene (PS) tray+polyvinyl chloride (PVC) wrapper. The physiological changes (weight loss, gas composition, color, firmness, and sensory evaluation) associated with postharvest deterioration were monitored for 17 days at $10^{\circ}C$. The results showed that the PP film bag maintained quality of mushrooms most effectively, especially PP film bags inhibited decreasing firmness. The samples also exhibited smaller decreases in weight loss rate (0.57%) and Hunter L value (84.44) than PS tray+PVC wrapper (7.73%, 82.19) and PE film bags (0.89%, 82.96). Sensory evaluation level in all samples remained relatively constant during the first 5 days of storage. However, PE film bags and PS tray+PVC wrapper showed lower score of flavor, texture and color than PP film bags after 8 days of storage. This study suggested that PP film bag packaging effectively extends shelf-life of mushrooms during storage.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.23 no.3
• /
• pp.133-141
• /
• 2017

This article described the development of transparent antimicrobial oxo-biodegradable (AOB) film with the function of enhanced freshness of food by employing oxo-biodegradable masterbatch (MB) and antimicrobial MB together with organic metal salt, organic acid, or unsaturated fatty acid. Antibacterial test of the AOB film with the different contents of the antimicrobial MB resulted in the significant freshness extension of plum. Tensile strength and elongation rate of the AOB films before UV treatment were similar to those of polyethylene films used as control. The reduced mechanical properties of AOB film after UV treatment (340 nm) suggested that the AOB film could be degraded by oxo biodegradation. The developed AOB films can effectively prevent decomposition of food by providing antibacterial function and preserving freshness.