초록 ▼

○ 연구결과
주요연구결과를 보면 1세부과제에서는 농가활용중인 봉지종류별 품질 및 예조처리의 영향, 과실형태별 저장반응 및 신개발 구연산칼슘처리 효과, 저장 전처리 방법에 따른 품질비교 및 유통기간 중 신선도 유지를 위한 포장방법의 개선에 대한 결과를 도출하였다. 2세부과제에서는 에틸렌 및 1-MCP처리의 영향, 물리적 충격에 따른 과실반응 및 1-MCP 처리의 영향, 유통지역별 온도 스트레스에 따른 변화, 유통중 고온스트레스 경감을 위한 패드 처리의 효과 및 품종별 에틸렌 생합성관련 ACS 유전분석을 실시하였다. 협동과제로 수

○ 연구결과
주요연구결과를 보면 1세부과제에서는 농가활용중인 봉지종류별 품질 및 예조처리의 영향, 과실형태별 저장반응 및 신개발 구연산칼슘처리 효과, 저장 전처리 방법에 따른 품질비교 및 유통기간 중 신선도 유지를 위한 포장방법의 개선에 대한 결과를 도출하였다. 2세부과제에서는 에틸렌 및 1-MCP처리의 영향, 물리적 충격에 따른 과실반응 및 1-MCP 처리의 영향, 유통지역별 온도 스트레스에 따른 변화, 유통중 고온스트레스 경감을 위한 패드 처리의 효과 및 품종별 에틸렌 생합성관련 ACS 유전분석을 실시하였다. 협동과제로 수행된 내용은 만개기 및 수확기 예측 모델의 개발 및 개발된 공식 중 기기적용이 가능한 공식을 이용하여 계측기기를 개발하였다.

Abstract ▼

'Niitaka' pear fruit tends to show severe physiological disorders during long period of low temperature storage and extended shelf life. In the present experiments, we evaluate several experimental approaches related to the prevention of physiological disorders and keeping the freshness of Korean 'N

'Niitaka' pear fruit tends to show severe physiological disorders during long period of low temperature storage and extended shelf life. In the present experiments, we evaluate several experimental approaches related to the prevention of physiological disorders and keeping the freshness of Korean 'Niitaka' pear for the acceleration of exportation. For this, we discussed three categories, (1) Study of factors affecting physiological disorders during storage and shelf life in 'Niitaka' pears, (2) Study of ethylene susceptibility and stress-related physiological change in 'Niitaka' pears, and (3) Establishment of Forecasting Programs for Premium Quality 'Niitaka' Pear.
We examined physiological and chemical characteristics of unripe and ripe 'Niitaka' pears (Pyrus pyrifolia 'Nakai') at harvest and during 4 months of cold storage. Decrease of fruit quality factor was prominent in ripe fruit when compared with unripe fruit and incidence of physiological disorders were increased as low temperature storage time passes.
Fruits of colored-paperbag treated ones showed promotion of skin color development but induced high incidence of physiological disorders including skin contamination, skin blackening and core breakdown when we compared with roll paper or charcoal treated roll paper which showed 40% less incidence of skin light browning(skin sooty dapple). We also confirm the effects of pre-drying treatments on Asian pear fruits before cold storage, incompletion of pre-drying induced severe increase of physiological disorders regardless of used paperbags.
Comparison of fruit quality between calyx perpetual and calyx deciduous 'Niitaka' pears during storage also examined. Calyx perpetual fruit which showed inferior appearance did not differ in quality factors but developed a higher incidence of physiological disorder compared to calyx deciduous fruit, showed 5 or 2.5 times higher rate of core breakdown after 3-5 months of cold storage, respectively.
Fruit clusters of 'Niitaka' pear were sprayed at 35-40 days after full bloom with ascorbic acid at 0.1% solution. Single spray of those chemicals increased flesh firmness, soluble solids and external appearance at harvest time. This treatment also effective on the prevention of the physiological disorders during 5 months of cold storage, skin blackening and core breakdown incidence decreased to the extent of one third and half of untreated control, respectively.
Incidence of pithiness during 4 months of cold storage decreased up to 50% with the combination treatment of calcium citrate solution spray at 40 days after full bloom and continued bagging with charcoal- or nanosilver charcoal-treated fruit bag. However, the influence of paperbags on this disorder were not appeared with the absence of calcium spray.
Considerable deterioration of fruit quality was observed with customary pre-storage fruit container coverings. Severe contamination of fruit skin and high incidence of skin blackening and pithiness were observed in the fruit block stored together with paperbags during 3 months of cold storage period. Polyethylene film covering of fruit container decreased incidence of core breakdown when compared with uncovered control, while newspaper covering was not effective on the prevention of this disorder.
Polyethylene film(PE) covering also completely prevent fruit skin wrinkle induced by water loss during storage period, no wrinkles were observed in the fruit blocks of PE while newspaper and untreated control increased incidence of this disorder to the extent of 34 and 67%, respectively. Whereas, 10% punctured PE(PEP) and charcoal treated paper effectively prevent this disorder, only 3.3 and 4.5% of the stored fruits were disordered. Significant differences between covering materials were observed for storage disorders. Charcoal treated papers were revealed as a better material for the reduction of external disorders such as skin blackening and skin light browning(skin sooty dapple) during three months of cold storage when compared with PE and newspaper. On the other hand, PE and PEP effectively reduced internal disorder core breakdown when compared with untreated control and papers.
As a pre-storage treatment, ozone irradiation for 5 or 1 min affected adversely on fruit quality and incidence of physiological disorders during cold storage. Meanwhile, UV-C irradiation for 2 min revealed somewhat effective on the maintenance of external appearance and the mitigation of skin light browning.
For the development of fresh-keeping absorber in paper box, we tested several absorbant such as silica gel, activated charcoal, carbon ceramic and ethylene scrubber. Occurrence of skin browning and core breakdown considerably decreased by the addition of the pack of carbon ceramic in the box, while the pack of silica gel decreased external appearance by excess loss of fruit moisture.
The use of 1-MCP at 1000ppb was very effective on the control of storage disorders without any adverse effects on fruit quality during two months of cold storage. No pithiness disorder was found in 1-MCP treated fruits, and the occurrence of core breakdown was as low as 20% of untreated control, while the treatment of ethylene at 100ppm promoted those disorders considerably.
We tested the influence of the artificial damage (wounding) on the fruit quality factors and the occurrence of physiological disorders during 4 months of cold storage in 'Niitaka' pears. Artificially damaged fruit showed decrease of external appearance after four months of cold storage. Typically wounding treatment increase core breakdown and pithiness up to 3 times when compared with sound fruits. The direct use of 1-MCP at 1000ppb on a box capable of containing 5kg for exportation was compatible with mitigation of the disorders in mechanically damaged fruit resulting in fruit that can reduce the incidence of flesh browning and pithiness disorder than non-treated fruit during month of simulated exportation.
Differences in low temperature acclimation before cold storage in harvested warm fruits were large between selected temperature. There was considerable decrease in firmness of the fruits stored directly to $1^{\circ}C$ without any temperature acclimation, while the fruits of acclimated at 4 to $12^{\circ}C$ maintained their firmness fairly high during 4 months of cold storage. The fruits of temperature acclimated during three days at 8 or $12^{\circ}C$ showed better quality and lower incidence of storage disorder than those of untreated one.
Influence of high temperature stress during shelf life in stored cold fruits were tested. There was considerable increase in weight loss of the fruits marketed at high temperature($30^{\circ}C$) which showed 3 times higher than those of low temperature($10^{\circ}C$) or room temperature($20^{\circ}C$). The fruits marketed at $30^{\circ}C$ showed high incidence of external and internal disorders and the trends were increased coincide with the duration of shelf life.
For the prevention of high temperature stress during shelf life in stored cold fruits, we tested the effects of several pads which consisted of carbon ceramic, illite and zeolite. Insertion of illite and zeolite powder on the inside of the paper pad fairly effective on the prevention of physiological disorders such as internal (flesh) browning, core breakdown and pithiness. In particular, illite treated pad ffected more than 50% overall reduction in skin light browning and pithiness isorder during 5 days of shelf life at $30^{\circ}C$ in 'Niitaka' pears.
Using genes encoding for ethylene biosynthetic enzymes as probes, RFLP nalysis was conducted for the pears grown in Korea and Korean native one. FLPs were designated as A(2.8kb of PPACS1), linked to high levels of ethylene(10ul/kg $\geq$ F.W./hr) and B(0.8kb of PPACS2), linked to moderate levels of ethylene(0.5ul/kg F.W./hr - 10ul/kg F.W./hr), when the total DNA was digested by HindIII. Four RFLP types(AB, Ab, aB, ab) were identified based on RFLPs using this gene diagnosis. Based on those methods, 'Minibae', 'Shinchun', 'Josaengwhangkeum' identified as a fruit of moderate ethylene production(aB) type. On the other hand, 'Sunhwang', 'Shinil', 'Wonhwang', 'Whangkeumbae', 'Hwasan', 'Niitaka', 'Gamchunbae', ''Chuwhangbae', 'Mansoo', 'Mihwang' identified as a fruit of lowest ethylene production type. This research will be very useful for breeding strategies to improve storage potential in Korean pears.
Hourly development rate model was established for predict full bloom date of 'Niitaka' pear cultivar. The difference of predicted and observed full bloom date was -2$\sim$1 days in NaJu region and -5$\sim$4days in Cheonan. The degree of estimation precision by hourly development rate model was improved 3$\sim$4days compared with regression model and daily development rate model. The model to predict the harvest time was established using climatic factors of young fruit season and August. The difference of predicted and observed harvest time was -5$\sim$5days.

목차 Contents

• 표지 ... 1
• 제출문 ... 2
• 요약문 ... 3
• SUMMARY ... 11
• CONTENTS ... 16
• 목차 ... 18
• 제 1 장 연구개발과제의 개요 ... 20
• 제 1 절. 연구개발의 목적 및 필요성 ... 20
• 제 2 절. 연구개발내용 및 범위 ... 23
• 제 2 장. 국내외 기술개발 현황 ... 25
• 제 3 장. 연구 개발수행 내용 및 결과 ... 28
• I. 신고 배의 과피흑변 등 생리장해 발생요인 구명 ... 28
• 1. 신고 배의 성숙도가 저장 중 생리장해 및 과실품질에 미치는 영향 ... 28
• 2. 봉지 종류 및 예조처리가 신고 배 과실품질 및 생리장해 발생에 미치는 영향 ... 30
• 2.1. 봉지종류별 성숙기 과실 품질 비교 ... 32
• 2.2. 수출용 신고에 있어 봉지종류별 예조 처리의 효과 ... 33
• 2.3. 지베렐린 도포 신고에 있어 봉지종류별 예조 처리 효과 ... 39
• 2.4. 신개발 숯 봉지가 저장 중 과실품질 및 생리장해에 미치는 영향 ... 42
• 3. 과실형태 및 칼슘처리가 저온저장 중 과실품질 및 생리장해에 미치는 영향 ... 48
• 3.1. 과실형태별 저온저장 중 과실품질 및 생리장해에 미치는 영향 ... 49
• 3.2. 유과기 칼슘 급원 및 ascorbic acid 복합처리의 효과 구명 ... 52
• 3.3. 유과기 칼슘 및 예조처리가 저온 저장 중 과실품질 및 생리장해에 미치는 영향 ... 54
• 3.4. 유과기 칼슘처리 과실의 은나노숯봉지 괘대처리의 효과 ... 57
• 4. 저장 전처리 방법이 신고 배 과실품질 및 생리장해 발생에 미치는 영향 ... 63
• 4.1. 농가 관행 저장 전 처리들의 효과 비교 ... 63
• 4.2. 컨테이너 피복처리가 과실품질 및 생리장해 발생에 미치는 영향 ... 66
• 4.3. 선과라인내 UV 살균시스템 도입을 위한 타당성 검토 ... 70
• 4.4. UV 및 오존처리가 수출기간 중 생리장해 및 과실품질에 미치는 영향 ... 75
• 5. 유통기간 중 신선도 유지를 위한 포장방법의 개선 ... 81
• 5.1 수출기간 중 신선도유지를 위한 내장재들의 효과 구명 ... 82
• 5.2. 숯함유 포장 패드의 개발 타당성 검토 ... 86
• II. 배의 에틸렌 감수성과 스트레스관련 생리변화 추적 ... 88
• 1. 1-MCP 및 에틸렌처리가 신고배의 저장 중 생리장해 및 품질에 미치는 영향 ... 88
• 2. 물리적 충격이 신고 배의 과실품질 및 생리장해 발생에 미치는 영향 ... 90
• 3. 1-MCP 처리가 물리적 충격 및 수출기간 중 과실 품질에 미치는 영향 ... 94
• 4. 저장전 온도스트레스가 신고 배의 저장 중 품질 및 생리장해에 미치는 영향 ... 97
• 5. 수출배의 유통지역 온도 스트레스가 과실품질에 미치는 영향 ... 102
• 6. 수출배의 유통온도 스트레스경감을 위한 박스 내 패드처리의 효과 ... 107
• 7. 품종별 에틸렌 생합성관련 ACS 유전분석 ... 113
• III. 고품질 배 생산을 위한 권역별 개화기, 수확기 예측프로그램 구축 ... 116
• 1. 재료 및 방법 ... 116
• 2. 결과 및 고찰 ... 117
• 3. 개화기, 수확기 예측기기(적산온도계)의 개발 ... 128
• 제 4 장 목표달성도 및 관련분야에의 기여도 ... 135
• 제 1 절. 목표 달성도 ... 135
• 제 2 절. 관련분야에의 기여도 ... 136
• 제 5 장 연구개발결과의 활용계획 ... 137
• 제 6 장 연구개발과정에서 수집한 해외과학기술정보 ... 138
• 제 7 장 참고문헌 ... 139
• 부록 ... 145
• 끝페이지 ... 148