• Korean Journal of Food Science and Technology
• /
• v.1 no.1
• /
• pp.51-61
• /
• 1969

In order to eliminate the considerable loss of rice by insects, to protect the human body from toxin excreted by some microbes, and to promote the storage efficiency of rice by employing the irradiation, the following experiments were carried out. Two varieties of rice, Paldal and Nongkwang polished and unpolished by the conventional methods and were packaged in polyethylene bags. After irradiating to the doses of 6-400 Krad of gamma-radiation from a $Co-^{60}$ source the samples were stored at the room temperature $20^{\circ}C$ for 8 months. The effects of radiation in terms of the removal of insects and microbes and the changes of chemical components (such as moisture, amylose, free sugar, and rancidity) were determined monthly from march to October during the storage. 1) Infestation of insects was greatly influeneed by the packaging materials used. There was no infestation in rice being packaged in a polyethylene bag, while as the rice packaged in a straw sack was infested in two months of the storage. 2) Some yeast and molds survived 400 K rad of radiation. Sterilizing dose to inhibit reproduction and growth of microbes was presumed to be higher than 400 K rad. Yeast mainly were found on the surface of rice, but mold were embeded into rice kernels by mycelium. 3) Changes of moisture contents during storage was not affected by radiation but was by humidity of the storage room. 4) Amylose content in starch increased with increasing dose of radiation and with the length of storage time, indicating possible depolymerization of starch molecules. 5) Free reducing sugar content was not affected by radiation and decreased with storage time. 6) Rancidity also increased with does and storage time.

• Analytical Science and Technology
• /
• v.32 no.6
• /
• pp.233-242
• /
• 2019

Substance identification is the first step of the REACH registration. It is essential in terms of Classification, Labelling and Packaging (CLP) regulation and because even trace amounts of impurities or additives can affect the classification. In this study, a scheme for the screening, quantification, and interpretation of trace amounts of hazardous inorganic substances is proposed to detect the presence of more than 0.1% hazardous inorganic substances that have been affecting the hazard classification. An exemplary list of hazardous inorganic substances was created from the substances of very high concern (SVHCs) in REACH. Among 201 SVHCs, there were 67 inorganic SVHCs containing at least one or ~2-3 heavy metals, such as As, Cd, Co, Cr, Pb, Sb, and Sn, in their molecular formula. The inorganic SVHCs are listed in excel format with a search function for these heavy metals so that the hazardous inorganic substances, including each heavy metal and the calculated ratio of its atomic weight to molecular weight of the hazardous inorganic substance containing it, can be searched. The case study was conducted to confirm the validity of the established scheme with zinc oxide (ZnO). In a substance that is made of ZnO, Pb was screened by XRF analysis and measured to be 0.04% (w/w) by ICP-OES analysis. After referring to the list, the presence of Pb was interpreted just as an impurity, but not as an impurity relevant for the classification. Future studies are needed to expand on this exemplary list of hazardous inorganic substances using proper regulatory data sources.

• Preventive Nutrition and Food Science
• /
• v.10 no.3
• /
• pp.262-266
• /
• 2005

Soybean has been favored by many Thai people and it has been prepared by numerous different methods. Collected samples are as follows: Thua-nao paste from Chiangrai province, dried Thua-nao for Jatujak Market, Bangkok, 3 types of commercial soybean paste, soybean sauce and 2 types of fermented soybean curd cakes with other ingredients. Moisture contents of fresh and dried Thua-nao were 68.5 and $7.6\%$, respectively; therefore the shelf-life of dried Thua-nao can be extended to 1 year with proper packaging. The remainder of the soy foods had moisture contents of 55.4 to $64.4\%$. Fat contents of fresh and dried Thua-nao were 7.4 and $19.7\%$, respectively, whereas other samples contained less than $3\%$. Dried Thua-nao had the highest CHO (carbohydrates) content $(37.4\%);$ in contrast, soybean sauce contained only $4.5\%$. Calcium content was highest in dried Thua-nao followed by fresh Thua-nao; the other fermented soy foods had less than 44.7 mg/l00 g. Salt was added to samples other than Thua-nao resulting in high Na contents. Free and total daidzein contents of dried Thua-nao were 355 and 676 ug/g; similarly free and total genistein contents were 293 and $616.5\;\mug/g$, respectively.

• Korean Journal of Food Science and Technology
• /
• v.44 no.6
• /
• pp.711-715
• /
• 2012

A laminate-composite film was developed using industry co-products of defatted mustard meal (DMM) and whey protein isolate (WPI). An individually prepared DMM-based film (DMM film) and a WPI-based film (WPI film) were thermally laminated at $130^{\circ}C$ at a rate of 30 cm/min. Microscopic images exhibited that the DMM film and the WPI film were continuously attached in the laminate without void spaces. The tensile strength, elongation at break, and water vapor permeability for the laminate were 0.7MPa, 4.0%, and $6.9g{\cdot}mm/kPa/h/m^2$, respectively. Stretchability and heat seal strength of the laminate were higher than those of the un-laminated DMM film. The film layers of the laminate were physically overlapped, not forming new biopolymer units induced by molecular interactions. The opportunity for DMM films to be used as food packaging materials for wrapping and sealing could be increased by thermal lamination with WPI films, which improves the stretchability and heat sealability of DMM films.

• Journal of Dairy Science and Biotechnology
• /
• v.24 no.1
• /
• pp.9-18
• /
• 2006

Total 150 packs of UHT milk and UHT-ESL milk, produced by different domestic milk companies, were compared at refrigerated and room temperature for 35 days in terms of microbiological qualities such as incidence date, number of incidence packs, and numbers of bacteria, and post-pasteurization contamination. Overall qualities of UHT-ESL milk were slightly better than that of UHT milk in relations to total bacteria in milk. No coliforms were detected in two groups of UHT milk samples after 35 days. Aerobic spores were more common in two brands of UHT milks stored in 20$^{\circ}$C than those in 7$^{\circ}$C, in which spores were broken out at 7 and 14 day. No incidences of thermoduric bacteria were founded until 14 days in two groups of UHT milks, but high level of counts (<300${\sim}$<3,000 CFU/ml) after 21 days at 20$^{\circ}$C and 40${\sim}$3,600 CFU/ml at 7$^{\circ}$C were detected, respectively. Psychrotrophic bacteria were higher in UHT milk than in UHT-ESL milk, in which began to detect at 28 days. No post-pasteurization contamination by salmonella spp. and staphylococcus aureus were found throughout the experimental periods. One may conclude that the shelf life of UHT milk under cold-chains system can be extended up to 21days, as long as UHT treated milk are filled in sterilized containers by aseptic packaging system.

• Korean Journal of Food Science and Technology
• /
• v.32 no.6
• /
• pp.1278-1284
• /
• 2000

The study was performed to elucidate the effects of ethylene-absorbent on the quality of 'Fuyu' persimmon fruits in the MA package. Five persimmons were packed in a MA package film (low density polyethylene, 0.055 mm film thickness), and stored at $-0.5^{\circ}C$ for 60 days. Two persimmons were repacked in a MA package with or without ethylene absorbent $(1\;M\;KMnO_4+zeolite)$ and stored at $-0.5^{\circ}C$. Ten days later, these packages was moved to $2^{\circ}C$ or $25^{\circ}C$ storage room to examine the effect of the ethylene-absorbent on the quality of the fruits. Ethylene removal by enclosed ethylene absorbent in MA packaging reduced the rate of fruit respiration at $25^{\circ}C$, so that $O_2$ and $CO_2$ concentration in packing were maintained higher and lower, respectively, compared to control. These effects were not observed, however, in $2^{\circ}C$ post-storage. Fruit firmness and sugar composition were also influenced by ethylene absorbent, showing more delayed flesh softening and higher sucrose concentration in ethylene absorbent treated fruits than control. But ethylene-absorbent treatment lowered glucose and fructose concentration. That shows that ethylene could influence on sugar composition by inhibiting sucrose inversion to glucose and fructose. The production of ethanol and acetaldehyde was reduced by ethylene removal, but the effect was not so high as other quality indices.

• Korean Journal of Food Science and Technology
• /
• v.36 no.5
• /
• pp.733-739
• /
• 2004

Model for optimally dimensioned PE film bag was developed according to fruit size to maintain best quality of 'Fuyu' persimmon in modified atmosphere packaging (MAP) storage based on relationship between quality and oxygen and carbon dioxide in PE film bag. Harvested persimmons were graded into five sizes, and average weights were LL:261, L:217, M:188, S:168, and SS:154 g. Five fruit units of each grade were optimized in five PE film bag sizes of $150{\times}376,\;140{\times}357,\;130{\times}344,\;130{\times}333,\;and\;120{\times}3l8\;mm$. To minimize quality deterioration such as softening and discoloration, optimal oxygen and carbon dioxide concentrations in PE film bag were 0.5-1.0 and 6.0-8.0%, respectively, and optimal thickness of PE film bag according to fruit size were LL:45, L:50, M:55, S:60, and $SS:65\;{\mu}m$. For all fruit sizes, model for PE film bag area $(mm^2)$ was good quadratic simple equation by fruit weight (g): $Y=-4055.707+627.993X_1-0.701{X_1}^2$. Model far optimal oxygen and carbon dioxide (Y) concentration in PE film bag was suited to linear multiple equation by fruit weight $(X_1,\;g)$ and PE film thickness $(X_2,\;{\mu}m)$. Equations for oxygen and carbon dioxide concentrations (%) were $Y=5.798-0.0109X_l-0.0491X_2\;and\;Y=-2.427+0.01927X_l +0.09646X_2$, respectively.

• Korean Journal of Food Science and Technology
• /
• v.17 no.6
• /
• pp.474-481
• /
• 1985

Radurization effects on fried fish meat paste with Co-60 gamma irradiation at 0-5 kGy and physicochemical aspects of the stored samples at low ($3{\pm}1^{\circ}C$, LT) and room ($10-20^{\circ}C$, RT) temperatures were investigated. The initial microbial loads of the samples were $2.2{\times}10^3/g$ in total bacterial count, $2.8{\times}10^2/g$ in yeasts & molds, and $1.0{\times}10^2/g$ in coliform group, respectively. An irradiation dose of more than 3 kGy was shown to be effective for the radurization of stored samples and there is no apparent difference between air and vacuum packaging groups. The chemical components related to the quality underwent similar changes in the nonirradiated and irradiated groups; however, as the storage time was prolonged the quality of nonirradiated samples rapidly deteriorated. Textural parameters of the samples were little affected by the applied doses, and sensory evaluations showed that 3 kGy irradiation was the optimum dose level to extend the shelf-life of fried fish meat paste up to 2 times at RT and 3 to 4 times at LT, respectively compared with the nonirradiated control.

• Journal of Mushroom
• /
• v.10 no.4
• /
• pp.191-197
• /
• 2012

This study was carried out to investigate proper modified atmosphere condition of king oyster mushroom (Pleurotus eryngii) during cold storage and distribution. King oyster mushrooms were divided into two treatments: $1{\mu}L/L$ 1-methylcyclopropene for 20 hours at $0^{\circ}C$ (1-MCP), while the other treatment was left at $0^{\circ}C$ (control). They were packaged with $30{\mu}m$ oriented polypropylene (OPP, $1238.0cc/m^2{\cdot}day{\cdot}atm\;O_2$), and microperforated (MP3, $3179.9cc/m^2{\cdot}day{\cdot}atm\;O_2$) film. Quality and sensory evaluation parameters of weight loss, stem firmness, skin color, off-flavor, overall quality were monitored after 3, and 4 weeks storage at $0^{\circ}C$ and plus 3 days on the shelf at room temperature. 1-MCP treated mushroom packaged with MP3 film kept 3.6~10.9% $O_2$ and 9.0~13.3% $CO_2$ concentration in the bag during storage, and showed high overall quality at 4 weeks storage at $0^{\circ}C$ + 3 days on the shelf at room temperature because of the lowest development of off-flavor, stem discoloration, and cap softening among the treatments.

• Clean Technology
• /
• v.21 no.3
• /
• pp.141-152
• /
• 2015

As environmental issues are emerging, bio-plastic suppliers in leading countries have been foreseeing the strong needs for environment-friendly materials such as eco-packing materials due to increased attention and regulation on recycle. To catch up with the demand, various types of bio-plastics based on natural feedstocks were developed and released on a market. These bio-plastic products drew the great attention even in domestic industries. At present, international oil price fluctuation and heavy charge on waste raise the unit cost of production and disposal expense of conventional plastic materials. These conditions make bio-plastic an alternative, because it is not restrained by oil prices and problem in the disposal. It is also expected that bio-plastic will be applied to various types of products including containers, industrial supplies, disposables, and medical supplies. However, the bio-plastic is still in its infancy, thus more research and understanding should be followed to put it to application. Bio-plastic is considered as environment-friendly material with high potential which has the advantages of production and disposal.