• The Korean Journal of Mycology
• /
• v.40 no.2
• /
• pp.118-123
• /
• 2012

In order to develop environment friendly fungicide for the control of citrus green mold (Penicillium digitatum) using endophytic bacteria, the 21 bacterial isolates were isolated from citrus leaves in seven different orchards in Jeju Province. Among the 21 bacterial isolates, 5 bacterial isolates presented antifungal activity against green mold pathogen P. digitatum. The CB3 isolate, which showed the most strong antagonistic effect, was selected through opposite culture against the pathogen. The rod-shaped, gram-positive bacterium CB3 was identified as Bacillus velezensis based on morphological, physiological characteristics, 16S rDNA, and gyr A gene sequence analysis. The isolate CB3 showed strong antifungal activity against two citrus postharvest pathogen P. digitatum. Citrus fruits were treated by wound inoculation with P. digitatum pathogen, and the control efficacy of CB3 culture broth was 66.7% ($1{\times}10^8$ cfu/ml). In conclusion, The stability of CB3 and its strong antifungal activity also lead us to believe that it has potential for application as an environment friendly biological control agent.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
• /
• 2000.04a
• /
• pp.12-13
• /
• 2000

최근 플라스틱제 식품 포장재에 대한 환경학적 문제가 제기됨으로 인하여 다양한 곡류 단백질의 필름 형성능력에 많은 관심이 모아지고 있다. 단백질 필름으로서 soy protein, wheat gluten, rice bran, corn zein, glatin 및 colloagen 등의 소재들이 많은 관심을 모으고 있으며, 비교적 필름 형성력이 뛰어나고, 저렴한 가격으로 구입할 수 있는 대두 단백질에 커다란 관심이 모아지고 있는 실정이다. 이들 물질로부터 제조된 가식성 필름 및 코팅제들은 식품의 보존기간을 연장시킬 뿐만 아니라 수분 및 용질의 이동을 방지하여 식품의 품질을 개선시킬 수 있다. 또한 이들 필름 및 코팅제들은 산소 및 이산화탄소의 이동, 이로 인한 지방 산화 그리고 휘발성 향기성분들의 감소 등을 조절할 수 있다. 대두 단백질 필름의 사과 코팅제로서의 이용은 개별적 포장이 용이하지 않는 제품들의 코팅제로서 활용하여 대두 단백질 필름 및 코팅제의 잠재적 시장성을 확인하는 하나의 응용분야이다. 본 실험의 목적은 대두 단백질 코팅제를 후지와 golden delicious 사과에 코팅하여 상온 (22$^{\circ}C$)과 냉장온도(2-4$^{\circ}C$)에서 60일동안 보관하여 색도, 경도 및 산도 변화 등을 측정하여 저장 중 사과의 품질에 미치는 영향을 조사하였다. 대두 단백질 코팅제는 대두 단백 용액들 (5g, 8g, 10g/100mL water)에 glycerin (50% w/w의 단백질)을 가소재로 첨가한 후 알칼리 용액으로 pH 9.0에 맞추었다. 그런후 85$^{\circ}C$에서 30분간 가열하여 코팅제를 준비하였다. 후지 사과(붉은색)와 golden delicious 사과 (초록색)를 dipping 방법으로 코팅하여 60일도안 실온과 냉장온도에 저자하여 보존기간의 연장을 확인하였다. 사과품질의 결정인자는 Hunter L, a, b 색도값과 사과의 조직의 강도 (외부 및 내부) 그리고 산도 등을 측정하였다. 코팅된 후지 및 golden delicious 사과의 표피 및 내부 경도는 control과 비교하여 높은 경도를 유지하였다. 또한 냉장온도에서 30일 동안 보관하였을 때, control 사과와 거의 비슷한 경도를 유지하였다. 식품의 색도를 소비자의 기호를 결정하는 중요한 인자이다. 대두 단백질로 코팅된 후지 사과는 상온에서 20일 동안은 control에 비하여 약간의 색도의 증가를 보였으나, 그 후 60일 동안은 색도의 증가를 보이지 않았다. 그러나 냉장 보관한 control 후지 사과에 비하여 색도의 증가가 관찰되었다. 대두 단백질 코팅제가 사과의 색도 변화를 방지하는 효과를 가졌으나, 저장 온도가 색도의 변화에 더욱 큰 영향을 미침을 알 수 있었다. 대두 단백질로 코팅된 golden delicious는 상온에서60일 동안 보관하였을 경우, 사과표피의 색도 변화를 현저히 지연시킴을 확인하였다. 또한 control과 비교하여 성공적으로 사과에 코팅하였으며, 상온에서 보관하여을 때 사과의 품질을 30일 이상 연장하는 효과를 관찰하였다. 이들 결과로부터 대두단백질 필름이 과일 등의 포장제로서 이용할 가능성을 확인하였다.

• Horticultural Science & Technology
• /
• v.33 no.4
• /
• pp.542-549
• /
• 2015

This work was carried out to evaluate the effects of preharvest 1-methylcyclopropene (1-MCP, $Harvista^{TM}$) and postharvest 1-MCP ($SmartFresh^{TM}$) treatments on the fruit quality attributes of cold-stored 'Fuji' ( Malus domestica Borkh.) apples. Fruits were exposed to 0, 95, 125, or $250 mg{\cdot}L^{-1}$ $Harvista^{TM}$ at 3, 2, 1 weeks before harvest (WBH), and treated with 0 or $1{\mu}{\cdot}L^{-1}$ $SmartFresh^{TM}$ at harvest. Fruit was then stored for up to 180 days at $0{\pm}1^{\circ}C$. Fruit fresh weight, Hunter's value a, internal ethylene concentration (IEC), flesh firmness, titratable acidity (TA), and soluble solids content (SSC) in fruit treated with $Harvista^{TM}$ were not different from those of control fruit at harvest. During cold storage, flesh firmness and TA were higher in fruit treated with $250mg{\cdot}L^{-1}$ $Harvista^{TM}$ at 2 and 3 WBH than in control fruit. IEC was 5.5-10.0% lower in fruit treated with $250mg{\cdot}L^{-1}$ $Harvista^{TM}$ at 2 and 3 WBH compared with control fruit as storage duration progressed, while SSC was not affected. Furthermore, flesh firmness, TA, and IEC were affected neither by $Harvista^{TM}$ nor $Harvista^{TM}+SmartFresh^{TM}$ treatments, compared with those fruit quality attributes at harvest. The correlation maps indicated that IEC was negatively correlated with firmness and TA, regardless of $Harvista^{TM}$ application levels. In addition, positive correlations between fruit quality attributes were detected in treatments with $250mg{\cdot}L^{-1}$ $Harvista^{TM}+SmartFresh^{TM}$. Therefore, the results suggest that with a single application of $SmartFresh^{TM}$, a higher level of $Harvista^{TM}$ application would help in retention of fruit quality attributes during cold storage.

• Horticultural Science & Technology
• /
• v.33 no.5
• /
• pp.705-711
• /
• 2015

This study was conducted to maintain the postharvest shelf-life of summer strawberry cultivars 'Goha' and 'Flamengo' through $CO_2$ (90%) and $ClO_2$ gas ($5{\mu}L{\cdot}L^{-1}$) pre-treatment. The respiration rate of 'Goha' and 'Flamengo' treated with $CO_2$ and $CO_2$ + $ClO_2$ was the lowest during storage. The weight loss with $CO_2$ + $ClO_2$ treatment was about 1% lower than the control group and 'Goha' was the lowest during storage. The pre-treatments effect on soluble solids contents was minimized. The firmness with $CO_2$ and $CO_2$ + $ClO_2$ treatments was only about 30% higher than $ClO_2$ and control. The firmness of 'Goha' was about 2.15N and 'Flamengo' was 2.37N, 15 days after storage. Decayed fruit was shown from after 6 days after storage in control. Control group lost quality 10 days after storage due to decayed fruit rate 20% of 'Goha' and 'Flamengo'. $CO_2$ and $CO_2$ + $ClO_2$ treatments showed the lowest decay rate during storage. Especially, 'Goha' showed around 5% decay fruit rate 10 days after storage. As a result, $CO_2$ + $ClO_2$ pre-treatment is recommended to extend the shelf-life of the summer strawberries.

• Journal of Bio-Environment Control
• /
• v.25 no.3
• /
• pp.153-161
• /
• 2016

This study aims to determine the optimal maturity of strawberry fruits as affected by the application of lysophosphatidylethanolamine (LPE) and its optimal concentration for postharvest stability and quality. Prior to application of treatments, fruits that were classified into levels of maturity (0%, 50%, 70% and 100%) were air-dried for 40 minutes and stored in the refrigerator at $4^{\circ}C$ for 12 days. Fruits at 70% maturity were dipped into 0, 10, 50 and $100mg{\cdot}L^{-1}$ LPE solutions for 1 minute. A lower range of concentration (0, 2.5, 5, 10 and $25mg{\cdot}L^{-1}$) was applied to fruits at different maturity levels. Data on fresh weight, hardness at vertical and horizontal loading positions, color index and sugar content during storage were collected. Based on fruits with 70% maturity dipped in LPE concentrations, there were no significant differences found on fresh weight, color index and sugar content. However, the application of $10mg{\cdot}L^{-1}$ LPE gave the highest hardness at vertical loading position while $100mg{\cdot}L^{-1}$ had the lowest average. At lower range of LPE concentrations, fresh weight was not significantly affected by LPE application and maturity levels. Hardness of fruits was mainly based on the maturity of the fruits. Increased hardness was observed in the fruits with 70% maturity dipped into the $5mg{\cdot}L^{-1}$ of LPE solution. The hardness and Hunter's $L^*$ and $b^*$ value of 100% matured fruits gave lowest values despite the application of $25mg{\cdot}L^{-1}$ LPE 12 days after storage.

• Horticultural Science & Technology
• /
• v.17 no.3
• /
• pp.361-364
• /
• 1999

This study was conducted to examine the effects of pulsing treatment and to develop techniques treated right after harvest by grower for extending vase life and improving flower quality in cut freesia. Thirty minutes dipping treatment of STS 2 mM followed by 20 hr pulsing in sucrose 10% + BA 10 ppm + 8-HQS 300 ppm solution showed the best results in vase life and flower quality of cut freesia when kept in vase water. This pretreatment extended vase life by 24.7% than control, and improved quality of cut freesia significantly in flower diameter, percent flowering (35.4%), fresh weight, water uptake, and carotenoid content, and depressed ethylene production and respiration rate.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.39-39
• /
• 2017

In Asia, sweet potato (Ipomoea batatas) is a very important crop for starch production. Approximately 74.3% of the total sweet potato production quantity is produced in Asia (FAO, 2014) and China is the largest producer of sweet potato. Post-harvest management is particularly important because it is difficult to maintain the quality as well as quantity of sweet potatoes. Despite the importance of post-harvest management, researches on sweet potato have been focused on production-related study such as breeding of new variety, improved techniques of cultivation, so there is limited research on storage after harvest. Curing is a normal practice after sweet potato harvest to promote wound healing and extend postharvest storage life. In Korea, harvested sweet potatoes are usually cured for 4 to 7 days at $30-33^{\circ}C$ and 80-95% relative humidity within one week. Since the optimum storage temperature of sweet potato is regarded as $15-20^{\circ}C$, additional facilities and costs are required to raise the temperature for curing. However, the majority of small farmers do not have the capacity to provide additional facilities and costs. This study was initiated to suggest a new curing method to accelerate the wound healing by applying chemical oxidation to the wound surface of sweet potato. Oxidative stress is known to play an important role in the synthesis of secondary metabolites including lignin. In addition, chemical oxidation can be applied to prevent spoilage caused by microorganisms. Powerful gaseous oxidant with excellent penetration ability and superior sterilization effect was selected for this study. Lignification, weight loss, and spoilage rate of artificially wounded sweet potatoes were investigated after oxidant fumigation. There were clear differences in morphological analysis such as lignification pattern, lignin deposition color, and continuity of lignified cell layers between oxidant-fumigated sweet potatoes and control. These results show that gaseous oxidant can be used to supplement or replace the curing practice, to improve shelf-life as well as curing cost reduction.

• Korean Journal of Medicinal Crop Science
• /
• v.24 no.6
• /
• pp.458-463
• /
• 2016

Background: The objective of the present study was to investigate the effect of storage conditions on the growth of Saururus chinensis (Lour.) Baill. rootstock. Methods and Results: Rootstocks of S. chinensis were stored in either soil or vermiculite that had been treated with a control treatment, diluted wood vinegar (50 or 100-fold), DF-100 (50-fold), or 1-naphthylacetamide and at $5^{\circ}C$ or $15^{\circ}C$. After 8 weeks, the stored roots were planted in the field, and both plant height and leaf number were observed after transplantation. The greatest number of leaves ($5.60{\pm}0.80$) was produced by roots that had been stored in soil treated with 100 fold dilution of wood vinegar and at $5^{\circ}C$. Meanwhile the maximum plant height ($6.92{\pm}0.78cm$) at 30 d after transplanting was observed for rootstocks that had been stored in soil treated with the 100 fold dilution of wood vinegar and at $15^{\circ}C$, whereas the maximum plant height at 60 d after transplanting ($26.46{\pm}0.71cm$) was observed for rootstocks that had been stored in soil treated with the 100-fold dilution of wood vinegar and at $5^{\circ}C$. Therefore, the storage of rootstocks in soil treated with the 100-fold dilution of wood vinegar and at temperatures at or below $5^{\circ}C$ was most effective, and it can be used to prevent the decay of roots during the postharvest management of S. chinensis rootstocks. Conclusions: The results of the present study indicate that, among the parameters examined, the storage of roots in soil that had been treated with the 100-foil dilution of wood vinegar is the most effective method for improving the growth of S. chinensis.

• The Plant Pathology Journal
• /
• v.31 no.4
• /
• pp.414-420
• /
• 2015

Antifungal activities of crude extractum of Nanshancha Seed Cake (NSC), to inactivate postharvest pathogens were investigated. Highest inhibitory rate was found against C. musae, C. gloeosporioides and C. papaya P.Henn, which was much stronger than that by tea saponin. Compared to tea saponin, effects of NSC extractum was relatively weak and similar on C. gloeosporioides Penzig and P. italicum. In an in vivo study, best controlling effects by NSC extractum was found with banana anthracnose disease development, which showed no inhibitory effects by tea saponin. NSC extractum controlled in vitro C. musae growth through directly inhibiting germination rate and germ tube elongation, and causing distortation, rupture and indentation of C. musae mycelium. In banana fruit subject to C. musae inoculation, higher PAL, POD, GLU and CHT activity was observed in banana fruit treated with crude NSC extractum than that of water control fruits. Current study proved the best controlling effects of crude NSC extractum in C. musae in vitro and in vivo development, which through direct inhibition of C. musae growth and increasing defense system of the banana fruit.

• Horticultural Science & Technology
• /
• v.31 no.5
• /
• pp.573-579
• /
• 2013

This study was conducted to investigate optimal harvesting stage and the effects on cut roses of Korean cultivar harvested at different stages. Cut roses are harvested at three different flowering stages. The optimal harvesting stage of cut roses was different depending on varieties. The vase life of standard type 'Pink Song' and spray type 'Peace One' was extended when they were harvested in one and three stages, respectively. The vase life was generally increased when the cut roses were pretreated with a solution containing 2% sucrose + $200mg{\cdot}L^{-1}$ aluminum sulfate + $200mg{\cdot}L^{-1}$ $Mg(NO_3)_2$ + $50mg{\cdot}L^{-1}$ $CaCl_2$ as compared to the control regardless of the harvesting stage. And this pretreatment solution improved the flower quality of cut roses bred in Korea. But the effects of pretreatment were varied depending on the harvesting stage.