• KOREAN JOURNAL OF CROP SCIENCE
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• v.69 no.1
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• pp.34-48
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• 2024

The objective of this study was to evaluate the safety of biodegradable mulching films in soybean (Glycine max) cultivation by measuring their effects on crop growth and yield, film decomposition and soil chemical and physical properties. In 2022 and 2023, plant height, branch number, chlorophyll contents, yield components, and yield of soybean did not vary significantly in areas using PE films and biodegradable mulching films. The light transmission rate of the biodegradable mulching films ranged from 6.4 to 15.8% when measured 112 days after soybean transplanting, and was higher, on average, in 2023 than in 2022. In both years, degradation of the biodegradable mulching films began 20 days after soybean transplantation and increased over time. In addition, remains of biodegradable mulching films were present in fields at soybean harvest and remained until 50 days after harvest. Decomposition rates of the biodegradable mulching films at 112 days after soybean transplanting ranged from 9.8 to 26.7% in 2022 and 13 to 36% in 2023. Although soil pH and EC varied based on the year and timing of measurements, there was no significant difference between areas that used biodegradable mulching films and PE films. Soil organic matter, nitrate and exchangeable cation contents such as Ca, Mg, and K were not significantly different in areas that used both PE films and biodegradable films. However, significantly higher levels of available phosphoric acid content were measured in areas that used biodegradable mulch films E, S, and T. Regardless of which films were used, there were no significant differences in the soil's physical properties. In 2022 and 2023, there was no difference between areas that used biodegradable mulch films and PE films. However, soil temperature in mulched areas was 2℃ higher and soil moisture was 5-15% higher than in non-mulched areas. Barley growth was not affected by being planted in soil that had been used for soybean cultivation with biodegradable films. Therefore, the biodegradable mulch films used in this study can be used without negatively affecting the growth, yield, and soil environment of soybeans.

• Food Science and Preservation
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• v.23 no.5
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• pp.623-630
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• 2016

Inappropriate storage of fresh-cut onions may result in losses of good quality. To understand storage conditions for shelf-life and quality of fresh-cut onions, The effect of packing type and storage temperature on the quality of fresh-cut onions was evaluated. Onions stored at $0^{\circ}C$ for 2 months were peeled off after removing root and shoot parts. Each three peeled onions were packed in a polyethylene film (PE, $50{\mu}m$) or in a polyethylene/polypropylene film (PE/PP, $100{\mu}m$) with vacuum treatment (70 cmHg) and stored at different temperatures (4, and $10^{\circ}C$) for 21 days. The following analyses were examined to evaluate the quality of fresh-cut onions: microbial population, surface color, titratable acidity and pH, respiration rate, and sensory quality. Fresh-cut onions stored at $4^{\circ}C$ showed less aerobic and coliform bacterial population than those stored at $10^{\circ}C$ during observation periods. Fungal populations of fresh-cut onions packed in PE film stored at $10^{\circ}C$ increased significantly after 13 days. E. coli was not detected in all treatments during whole storage periods. Surface colors of fresh-cut onions were not affected by packing type and storage temperature, however, color difference (${\Delta}E$) of fresh-cut onions in PE/PP film stored at $10^{\circ}C$ was significantly higher than those of other treatments. Titratable acidity of fresh-cut onions was not affected by packing type and storage temperature. However, pH of fresh-cut onions packed in PE film stored at $10^{\circ}C$ increased gradually over the whole storage period. Fresh-cut onions packed in PE film showed higher $CO_2$ and less $O_2$ concentrations at $10^{\circ}C$ than those at $4^{\circ}C$. The sensory quality of fresh-cut onions was significantly affected by packing type and storage temperature after 13 days. Particularly, vacuum treatment in PE/PP film showed better sensory quality than that of PE film package at the same storage temperature. It was concluded that vacuum treatment and storage at $4^{\circ}C$ could be effective to prolong the quality of fresh-cut onions up to 21 days.

• Journal of Bio-Environment Control
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• v.11 no.4
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• pp.175-180
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• 2002

This study was conducted to examine the effect of row covering materials on the growth and yield of broccoli for early production in the open meld. Materials for plastic tunnel were row-covering (ventilating non-woven fabric), perforated film (2.3％ pore space) and P.E. film. The types of row covers were tunnel and covering period was one months after transplanting. The row cover and perforated film increased daily air and soil temperature by 3~4$^{\circ}C$ and 2~3$^{\circ}C$, respectively as compared to no covering. Also, relative humidities in those treatments were higher than those in P.E. and no covering. The row covering and perforated film enhanced plant growth. Broccoli grew best and abnormal head appeared the least with row covering treatment. Days taken for head formation, however, did not differ between treatments but the weight of curd was over 400 g in the treatment of row covering and perforated film covering. Marketable yield doubled under row covering as compared to no covering. The first harvest time was earlier by two weeks in row-covering. The results of this experiment indicated that covering row-cover film in spring cultivation was effective fer not only yield increase but also quality evaluation in early production of broccoli.

• Food Science and Preservation
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• v.8 no.4
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• pp.351-355
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• 2001

This study was carried out to examine the of quality on the dried Omija according to its package materials and storage plates. The changes of moisture contents, anthocyanin content, molds damage rates, and color values were measured during storage. In the sealing up by the P.E file, the moisture contents of the dried Omija had just a little differences among the storage places, but in the gauze bag remarkably as the storage period goes on, especially in this case, 8 months later since the storage in the cool chamber, the damage rates of the dried Omija by the mold was 9.0%, twice as much as in the indoor bag packaging it was increasand after 10 months, that was lather high in the indoor and warehouse. The anthocyanin content of the dried Omija after the storage of 10 months was the highest at 0.05mm black P.E film package in the cool chamber, which was 55.7 mg/100g, but in the indoor and warehouse 39.7, 45.0mg/100g, respectively. These results show thats the storage conditions had an important effect on the quality of the dried Omija during the long-term storage.

• Horticultural Science & Technology
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• v.33 no.3
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• pp.326-330
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• 2015

This study was conducted to examine the effect of tunnel covering materials on the growth and yield of red pepper in paddy fields. Materials for tunnel coverings included illite non-woven fabric and P.E film. Air and soil temperature were higher in the illite non-woven tunnel and P.E film tunnel by $7-8^{\circ}C$ and $2-3^{\circ}C$, respectively, compared to no covering. Relative humidity in those treatments was also higher than with no covering. The growth and yield were higher with illite non-woven tunnels and P.E film tunnels than with no covering. In particular, the yield was 30% and 26% higher in illite non-woven tunnels and P.E film tunnels, respectively, than with no covering.

• Korean Journal of Food Science and Technology
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• v.17 no.5
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• pp.331-335
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• 1985

Series of study were conducted to develop a method for longterm storage of chest-nut with preserving it's taste and freshness. Experiments were carried out with Korean chest-nut (Castanea crenata var. Okkwang) sealed in polyethylene (P.E) film stored under the ambient and low temperature. Summarized results are as follow: After the harvest, $CO_2$ produced by chest-nut at the early storage was increased with temperature increase. Q10 mg/kg/day, the temperature index of $CO_2$production, by chest-nut ranged 2.4-2.7. It was available to store chest-nut in good condition with 8-15% total loss upto the following may at the ambient temperature sealed in 0.03 mm P.E. film, and upto the following july at the low temperature if sealed in 0.03 or 0.05 mm P.E. film. Throughout the period from one month after the innitiation upto the end of the storage, the rate of $CO_2$and $O_2$ was maintained near the optimum condition for the CA storage of chest-nut. The taste of chest-nut was improved during the storage due to increased reducing-sugar and decreased wate soluble tannin. However, the taste become bitter and unacceptable from the early stage of the storage when used the thicker P.E. film (than above mentioned) for the sealing.

• Food Science and Preservation
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• v.5 no.4
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• pp.355-362
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• 1998

Polyethylene films contained 0, 10, 20, 30 and 40% of raw-ore powder(PERO) were prepared. The characteristics feature of the film and the powder were investigated in order to use packaging material for kimchi quality. Kimchi was packaged in the PERO bass md stored at 10$^{\circ}C$. The kimchi was examined for a pH, acidity, number of total microbe and lactic acid bacteria, E. coli, color values and sensory evaluation. The ore powder at 20$^{\circ}C$ produced infrared rays at 800-1100nm. The growth of E. coli md Staphylococcus aureus was extremely inhibited in the EMB and nutrient broth containing 10% of raw-ore powder but, that of lactobacillus plantarum and Leuconostoc mesenteriodes was slightly promoted in MRS broth containing 1%. The ripening by pH and acidity was slightly accelerated in kimchi in PERO bag(PERO-kimchi) compared to control kimchi but the maintenance of ripened-kimchi taste was prolonged in PERO-kimchi. The number of lactic acid bacteria of PERO-kimchi was more numerous than that of contol sample but that of E. coli wag exremely legs. The color L* values of PERO-kimchi was lower than control but a* and b* values were higher. Sensory evaluation of PERO-kimchi was higher score than control sample in crispness and overall taste about 10 to 20% of raw-ore contents for kimchi-packaging material was desirable.

• Korean journal of applied entomology
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• v.24 no.4 s.65
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• pp.173-177
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• 1986

This study was carried out to see what makes the 'dark grey cutworm', Agrotis tokionis Butler, inflict less damage in P.E. film-mulched tobacco fields than in nonmulched ones. In field plot experiment, the damage ratio of tobacco seed lings in mulched plots(m) was reduced by 63% compared with that in non mulched ones(n). The altered environments did not affect the cutworm in mortality, which was confirmed by recovery ratio, location of larvae in soil, and developmental age. But the m/n value and damage ratio in plots of different mulching methods strongly suggest that the P.E. film itself prevent larvae from cutting the plants. Larval mortality was rapidly increased between the end of July and the end of August.

• Food Science and Preservation
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• v.11 no.4
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• pp.565-568
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• 2004

To investigate the effect of soy protein film packaging on the quality of beef, the rate of weight loss, pH, 2-thiobarbituric acid reactive substance (TBARS), and microbial (total bacterial count) Salmonella spp., E. coli changes were determined during storage. Beef samples were packaged with soy protein film containing rosemary extract and then stored at $4^{\circ}C$. Soy protein film was effective on prevention of weight loss, compared with the control, regardless of addition of rosemary extract. Change in pH of soy protein films containing the rosemary extract (RPF) was less during storage, compared with the control. Packaging of beef products with RPF inhibited lipid oxidation by $86\%$ at day 8 of storage, compared to the control. RPF packaging also affected the microbial growth, resulting in retardation of total bacteria by more than 1 log cycle. These results indicate that storage of beef packaged with RPF should be appropriate in terms of quality as well as shelf-life.

• Journal of Bio-Environment Control
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• v.22 no.2
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• pp.81-86
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• 2013

This experiment was carried out to select white asparagus varieties suitable for shading culture in greenhouse. Eight white and one green varieties were tested. Seeds were sown in 72-cell trays in a glasshouse on 24 Dec. 2008 and the seedlings were transplanted in a P.E house on 22 May 2009. Planting distances were 30 cm apart in a raw and 125 cm between the raws. For white asparagus production, small tunnel ($210cm{\times}160cm$) was established inside the P.E house, and covered with black and white P.E film (0.1 mm) on 5 March 2010. Days to sprouting took 5 days in 'Ravel' variety and took 16 to 18 days in 'Backlim', 'Horlim', 'Herkolim' varieties. The number of spear was highest in 'Ravel' with 6 and lowest in 'Backlim' with 3.7. The spear weight was heaviest in 'Herkolim' with 25.6 g and lightest in 'Ravel' with 15.6 g. The highest total yield was in 'Herkolim' with 296 kg/10a, followed by 'Super welcome' with 275 kg/10a and lowest in 'Rapsody' with 176 kg/10a. Marketable yields in 'Super welcome' and 'Herkolim' were 241 kg/10a and 239 kg/10a, respectively, and the yield was lowest in 'Rapsody' with 139 kg/10a. The L grade (over 20 g of spear weight) was highest in 'Herkolim'. Accordingly, 'Herkolim' was the most suitable white asparagus variety among the tested varieties for shading cultivation in greenhouse.