• 한국환경농학회지
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• 제41권3호
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• pp.158-166
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• 2022

BACKGROUND: Kiwifruit is a fruit tree with relatively small cultivation area in Korea and researches on its soil and physiology are very limited compared to those on cultivar development. Therefore, there are limited information for farmers to cope with the reduction in productivity due to various physiological disorders and premature aging. This study was conducted to investigate the soil and leaf chemical properties, and fruit characteristics, which will be used as basic data for stable kiwifruit orchard soil management. METHODS AND RESULTS: The soil and leaf chemical properties, and fruit characteristics were investigated for two years in 16 kiwifruit orchards growing 'Hayward' (Actinidia deliciosa) in Jeollanam-do and Gyeongsangnam-do. Soil and leaf samples were collected in July and fruit quality was investigated by harvesting fruits about 170 days after full bloom. The average soil chemical properties of kiwi orchards were generally higher than the recommended level, except for pH, and especially, the exchangeable potassium reached about 300% of the recommended level. The proportions of orchards that exceeded the recommended level of soil chemical properties were 63, 31, 100, 69, 94, 88 and 69% for pH, EC, organic content, available phosphate, and exchangeable potassium, calcium and magnesium, respectively. Thirty-three percent of orchards had more than 100 mg/kg of nitrate nitrogen in soil. Available phosphate in soil showed a significantly positive correlation with leaf nitrogen, phosphoric acid and calcium content, but showed a significantly negative correlation with leaf potassium content. The magnesium content in the leaves was significantly correlated with soil pH. The highest fruit weight was observed in about 25 g/kg of leaf nitrogen content which could be attained when plants were grown on the soil containing about 100 mg/kg of nitrate nitrogen content. The average soluble solids content among 16 orchards was 9.58 °Brix at harvest and 13.9 °Brix after ripening, which increased about 45%, and the average fruit weight was about 110 g. CONCLUSION(S): For fruit quality, fruit soluble solids (sugar compounds) content was significantly correlated with leaf potassium content, fruit hardiness with leaf total nitrate, calcium and magnesium, and fruit titratable acidity with leaf magnesium; however, leaf calcium and magnesium negatively affect the soluble solids contents in fruits.

• 한국식품영양과학회지
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• 제31권4호
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• pp.594-598
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• 2002

과일의 방사선 조사 여부 확인과 저장에 따른 변화를 측정하기 위해 감마선 조사로 유도된 DNA손상을 comet assay로 확인하였다. 키위, 오렌지, 배를 구입하여 0.1, 0.3, 0.5, 0.7, 1.0 kGy의 저 선량으로 조사하고 비 조사 시료와 조사 시료간의 DNA 손상정도를 tail length와 tail moment로 측정하였다. 과일 씨의 DNA를 형광 염색하여 이미지 분석기를 이용하여 comet 양상을 관찰한 결과, 모든 시료에서 비 조사 시료보다 조사시료의 tail length가 더 길었으며 조사 선량이 증가할수록 tail length가 유의적으로 길게 나타났다. Tail moment로 나타난 결과도 이와 비슷하였으나 전체적으로 tail length에 비해 그 민감도가 낮았다. 방사선 조사한 과일을 저온에서 3개월 동안 저장한 후에도 저장 전과 마찬가지로 모든 시료에서 비 조사시료보다 조사 시료의 tail length가 더 길었으며, 조사 선량이 증가할수록 tail length가 길게 나타나, 저장 후에도 comet assay를 이용해 조사 시료와 조사 시료의 방사선 조사여부를 검지할 수 있었다 따라서 본 연구결과 comet assay는 신선한 과일과 일정기간 저장한 과일의 방사선 조사여부 판별에 유용하게 사용될 수 있음을 알 수 있었다.

• The Plant Pathology Journal
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• 제27권3호
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• pp.257-265
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• 2011

During 2002-2008 in Korea, 455 extracts from myxobacteria consisting of 318 cellulolytic and 137 bacteriolytic myxobacteria were isolated, which were then screened for antifungal activity against the phytopathogens Botrytis cinerea, Colletotrichum acutatum, Penicillium sp., Pyricularia grisea, and Phytophthora capsici. 204 isolates had antifungal activity, causing both a clear zone due to blocked spore germination and inhibition of mycelial growth; most (199) were from cellulolytic (Sorangium cellulosum) and only five were from bacteriolytic myxobacteria. B. cinerea, the best controlled among the five tested pathogens, had a unique group of antifungal isolates of myxobacterial extracts compared to the other pathogens' groups. Among seventy-nine bioactive myxobacteria, four isolates, KYC 3130, KYC 3247, KYC 3248 and KYC 3270, were selected and all were cellulolytic. Liquid culture filtrates of these four myxobacteria were applied to tomato, cherry tomato, strawberry, and kiwi fruits 5 h before inoculation with gray mold conidia; then the treated fruits were placed in an airtight container and the experiment was repeated six to eight times. Incidence (%) of gray mold on fruit of the infected control treatment was 84-98%, whereas it was only 5-21% after the KYC 3270 treatment. After KYC 3270 treatment of the four fruits, mold control was 79-95%, which was highest among the filtrates and statistically the same as treatment with fludioxonil, a registered chemical against gray mold of stored fruits.

• 한국환경농학회지
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• 제31권3호
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• pp.229-234
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• 2012

BACKGROUND: The fruit quality and flowering characteristics of Kiwifruit (A. deliciosa cv. Hayward) in the following year is known to be affected by the extent and timing of defoliation of the current year. In korea, the production of kiwi, which is a perennial, straggling deciduous warm-temperate fruit, is often restricted by wind damage due to typhoons resulting to defoliation at the middle season of its growing period. In this paper, we report the effect of the different timing of defoliation and severities at the current season to the kiwifruit quality. METHODS AND RESULTS: Twenty seven-year-old 'Hayward' trees grown under polyethylene film rain-shelter were defoliated in different days from August to September at seven day-intervals. In each day, 0, 25, 50, 75 and 100% of leaves were removed from the trees. Fruits from each treatment were classified into four floating types (L: lying in bottom, S: standing on bottom, F: floating and SF: floating at the surface of water) by submerging them into tap water. Defoliation of kiwifruit trees in August and September caused air holes in locules of inner pericarp. Increased number of air hole in locules of a fruit was observed in floating types F and SF, and most of the air holes were located in stem end. The defoliation of trees in August significantly reduced the ratio of L-floating type fruits, which have the least number of locule air holes. The extent of defoliation also affected the distribution of the four types, the more leaves removed, the less L-floating type fruits harvested. The weight of fruits from trees defoliated in August was lower than that of fruits from September. Soluble solids content decreased as the number of locule air holes increased. Negative correlations were observed between the extent of defoliation and the weight and soluble solids content of fruits. CONCLUSION: Early defoliation effect on kiwifruit locule air hole occurrence and fruit quality were more severe in August than in September. And also if the defoliation severity is over 25%, severe fruit quality reduction expected to happen due to increase of fruit locule air hole in the inner pericarp.

• Journal of Biosystems Engineering
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• 제21권1호
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• pp.44-51
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• 1996

The purpose of this paper is to obtain the basic data for design of pressure cooling system. Static pressure drop, as a function of superficial velocity, was measured for different stacking methods and stacking heights of some fruits and vegetables. At given superficial velocity, sphericity and void fraction had a much greater influence on static pressure drop than average diameter of spherical fruits such as apple, peach, tomato and kiwi fruit. Among cylindrical vegetables such as cucumber, carrot, radish and chinese cabbage, cucumber showed different pattern of static pressure drop because of its bended shape, radish showed less static pressure drop than other vegetables because its large sizes of voids. When cucumber and spinach were stacked vertically and horizontally to air flow, a much greater static pressure drop was shown in vertical than in horizontal type, therefore static pressure drop was affected not only by void fraction but also by void shape. Also, in packed-beds of fruits and vegetables, static pressure drop could be estimated very well by Ramsins equation.

• 대한가정학회지
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• 제31권4호
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• pp.201-208
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• 1993

The ascorbic acid contents of 101 food items were analyzed by HPLC to provide database to estimate dietary intakes of ascorbic acid of Korean. Foods with high contents of ascorbic acid were green vegetables, citrus fruits, strawberry, kiwi, and fruit juices. This analysis data of ascorbic acid contents in some food items showed significant deviations compared with other Food Composition Table. Ascorbic acid content in soups were lower than those of raw foods by about 57%. The ascorbic acid contents in blanched or seasoned after blanching vegetables and boiled or steamed meals turned out to be decreased by about 52.3% and 47.5%, respectively, but the degrees were varied with the kind of foods as well as cooking methods. The ascorbic acid intakes from 18 most frequently consumed meals in Korea were determined to be about 1/2 of Food Composition Table according to this analysis data. The results showed the importance of accurate food database in assessing nutrient intake levels of population.

• 한국식품과학회지
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• 제36권1호
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• pp.64-68
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• 2004

농산물중 과일과 채소류 6종류인 딸기, 단감, 키위, 양파, 마늘 및 오이를 대상으로 식물세포분리효소인 Sumyzyme MC 처리 후 얻어진 단세포 함유 반응물의 반응률, 용량, brix, 색도, 입도분포, 점도 및 현미경 관찰로 특성을 조사하였다. 단세포화 후 반응률은 단감과 딸기가 90% 이상, 키위가 80% 이상으로 원료에 따라 상이하였다. 이와 같이 농산물의 성분변화를 최소화하면서 단세포화에 필요한 적정 반응조건을 조사하였다. 단세포물에 함유된 수용성, 불용성 식이섬유가 풍부한 마늘의 경우 생시료의 총식이섬유의 함량이 30.77%인데 비하여 단세포물의 경우 18.55%로 나타났다. 식물세포분리효소에 의해 얻어진 과일, 채소류 단세포 함유 반응물의 미세구조 관찰에서 개개의 단세포화가 이루진 것으로 나타났다. 따라서 효소적으로 세포분리한 각종 과일, 채소류 단세포 함유 반응물은 단세포 함유 식품의 제조에 필요한 기본 원료로 이용될 수 있을 것으로 판단된다.

• 한국식품저장유통학회지
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• 제22권4호
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• pp.577-584
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• 2015

본 연구에서는 수입산 열대 아열대 과일의 항산화 효과를 비교하기 위하여 총 폴리페놀 함량, DPPH radical 소거능, ABTS radical 소거능, superoxide anion radical 소거능, FRAP 활성, tyrosinase 저해효과, 환원력 등을 측정하였다. 총 폴리페놀 함량은 석류가 12.22 mg GAE/g으로 가장 높았고 그 다음 순으로 파인애플이 3.77 mg GAE/g이었으며, 용과, 그린키위, 파파야, 옐로우망고가 2.45~2.99 mg GAE/g의 범위로 나타났다. 석류는 DPPH, ABTS, superoxide anion radical 소거능, 환원력에서 다른 과일보다 높은 활성을 보여주었고 그 다음으로 파인애플이 높은 활성을 보였다. 특히 석류는 추출물의 농도가 증가함에 따라 전반적으로 활성이 증가하는 경향을 보였고 시료 농도 5 mg/mL에서는 DPPH radical 소거능과 ABTS radical 소거능 및 환원력이 양성대조군으로 사용한 ascorbic acid와 대등한 효과를 보였다. 반면에, 용과와 파파야는 대부분의 항산화 효과 실험에서 낮은 활성을 나타내었다.

• 한국식품과학회지
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• 제30권6호
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• pp.1484-1487
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• 1998

국내에서 시판되고 있는 16종의 과실, 채소 착즙액 및 농축품의 SOD 유사활성을 pyrogallol autoxidation 방법을 이용하여 측정하였으며 이들의 열안정성, 사과주스에 첨가시 사과주스의 SOD 유사활성 상승효과를 조사하였다. SOD 유사활성은 브로콜리 착즙액이 41.7%, 딸기, 당근 착즙액 등이 30% 이상으로 높게 나타났으며 그 다음은 케일농축액, 키위 착즙액, 무 착즙액이 $24.1{\sim}27.6%$ 정도의 SOD 유사활성을 나타내었다. $95^{\circ}C$에서 20분까지 처리시에도 SOD 유사활성은 오히려 증가하는 경향을 나타내었다. 사과주스의 SOD 유사활성을 100%로 할 때 사과주스에 당근농축액과 키위착즙액을 20% 첨가시에는 120%정도, 딸기와 브로콜리 착즙액은 135%의 높은 SOD 유사활성 상승효과를 나타내었다. 특히 무 착즙액의 경우 사과주스에 20% 첨가시 148%로 가장 높은 상승효과를 나타내었다.

• 한국산학기술학회논문지
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• 제18권6호
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• pp.478-485
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• 2017

본 연구는 레드키위 과실의 수확 후 숙성반응에 미치는 이산화탄소와 외부 에틸렌처리 효과를 구명하기 위하여 수행되었다. 저장온도 $10^{\circ}C$에 75일 저장 기간 중 레드키위의 숙성과정에 영향을 미치는 이산화탄소와 에틸렌 처리 효과를 구명하기 위하여 과실의 생체 중, 경도, 가용성 당 함량, 유기산 및 시장성 품질 등 물리 화학적 특성을 분석하였다. 레드키위의 생체중은 이산화탄소 처리로 저장 75일후 까지 무 처리와 에틸렌 처리에 비하여 가장 적게 감소된 반면 에틸렌 처리된 과실은 가장 빠르게 감소되었다. 에틸렌 처리과실의 경도는 $10^{\circ}C$ 저온저장 27일 후 4.2kg에서 1.2kg으로 감소된 반면, 이산화탄소 처리된 레드키위 과실은 저장 54일 후까지 1.8kg을 유지하였다. 가용성 당 함량(%)은 에틸렌처리로 $10^{\circ}C$ 저장 27일 후 가장 높은 값을 보인 반면 이산화탄소 처리된 과실에서는 64일 저장 후 가장 높게 나타났다. 레드 키위 과실의 유기산함량은 이산화탄소 처리에서 대조 구와 에틸렌 처리된 과실에 비하여 $10^{\circ}C$에 41일 저장 동안 통계적으로 유의성 있는 높은 값을 유지하였다. 당산 비는 75일 저장 기간 동안 대조 구와 에틸렌 처리된 과일에 비하여 이산화탄소 처리된 키위 과실이 가장 낮은 값을 보였다. 본 연구에서 이산화탄소 처리가 수확 후 레드 키위 과실의 숙성지연과 시장성 품질유지에 매우 효과적으로 나타나 향후 키위 산업에 상업적인 목적으로 이용 가능할 것으로 밝혀졌다.