• 한국식품조리과학회지
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• 제19권2호
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• pp.181-187
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• 2003

The objective of this study was to investigate by a sensory evaluation and mechanical examination the sensory and quality characteristics of wageobyune containing different ratios of ingredients such as lettuce (50%, 60% and 70%), sugar and water. The results of the sensory evaluation showed that wageobyung containing 50% lettuce had higher scores in the overall acceptability, color, flavor and chewiness preference. In the textural analysis of wageobyung, the springiness, cohesiveness and hardness were the highest and the chewiness, gumminess and adhesiveness were the highest in the 70% added samples. Increasing the lettuce content decreased the hunter's color L-value of wageobyung. The redness and yellowness of wageobyung were increased as more lettuce was added. The moisture content of wageobyung was higher in the samples containing 70% lettuce than those containing 50%.

• Journal of Microbiology and Biotechnology
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• 제17권8호
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• pp.1284-1290
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• 2007

This study was conducted to investigate the antibacterial activity and shelf-life extension effect of iceberg lettuce packed in BN/PE film. The BN/PE film has a strong microbial suppression effect on pathogenic bacteria such as Escherichia coli, Salmonella enteritidis, and S. typhimurium. The number of psychrophiles and mesophiles during 5 days of cold storage of fresh-cut iceberg lettuce at $10^{\circ}C$ packaged in BN/PE film was strictly suppressed in comparison with other tested films (OPP, PE, and PET film). When fresh processed iceberg lettuce was processed and stored under the current conditions, the shelf-life of the product was longer than 5 days in the BN/PE film package, whereas the shelf-life when using the other films tested, PE, OPP and PET, was no longer than 3-4 days. The decay rates of the iceberg lettuce packed in the BN/PE film was maintained at $29.8{\pm}2.1%$ on the 5th day of preservation. The samples packed in BN/PE film maintained an excellent visual quality during the 3 days of storage without significant differences in comparison with the initial visual quality. No browning was observed in the samples packed in BN/PE film for up to 3 days. The texture of shredded iceberg lettuce packaged in BN/PE film remained unchanged up to 3 days, and then a moderate decrease in texture was observed after 4 days of storage. In addition, the overall acceptability of fresh-cut iceberg lettuce packaged in BN/PE film did not change for up to 3 days, whereas the samples packaged in the other films were inedible by 3 days of storage. In conclusion, the shelf-life of fresh-cut iceberg lettuce packaged in the BN/PE film was extended to more than 5 days at $10^{\circ}C$, whereas that in the other films was 2 days at $10^{\circ}C$. Therefore, the shelf-life extension effect of the fresh-cut iceberg lettuce in BN/PE film packaging was very effective compared with the other films tested.

• 한국식품저장유통학회지
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• 제13권1호
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• pp.8-12
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• 2006

상추의 포장 방법 및 저장 온도가 저장성에 미치는 영향을 분석하기 위하여, 저장중 감모율, 외관변화, 색상차, 안토시아닌 및 크로로필의 색소함량, 수분 함량을 측정하였다. 중량감모는 저온이라도 무포장(대조구)에서 급격히 일어났으며, 상온에서 저장할 경우, 유공 필름 순으로 중량감모가 나타났으며 LDPE와 PP 필름종류에 따라서는 30일간 저장하여도 차이가 크게 나타나지 않았다. 외관변화도 감모율과 비슷한 경향으로 대조구를 제외하면 온도, 천공여부, 필름종류 순으로 나타났다. 상추 저장 중 색상 변화는 저장조건 및 포장방법 처리에 의한 차이가 뚜렷이 나타나지는 않았다. 저장 중 안토시안닌은 증가하는 경향이고 클로로필은 감소하는 경향이었으나 저장온도와 포장 방법에 따른 처리간의 차이가 명확히 나타나지는 않았다. 저장 중 상추의 수분 함량 감소는 상온에서는 처리간의 차이 없이 감소하는 경향이었으나 저온에서는 포장 재료에 천공여부가 영향을 미쳐 유공필름에서 수분 감소가 더 일어났으나 LDPE와 PP필름간의 차이는 크게 나타나지 않았다. 본 실험결과 상추와 같은 엽채류의 품질 유지를 위해서는 포장하는 것이 가장 효율적이며 저온에서 저장하는 것이 상품성을 유지시키는데 효과적이며, 필름에 천공을 하면 저장성을 떨어뜨리며, 필름 재료에 따라 크게 선도에 영향을 미치지 않으므로, 천공을 하지 않으면서도 효과적으로 결로를 방지 할 수 있는 방법에 대한 연구가 필요할 것으로 생각된다.

• 한국유기농업학회지
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• 제19권4호
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• pp.589-602
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• 2011

In this study, experiments were conducted to determine the effect of different compost teas on plant growth reponses and yield of leaf lettuce. Compost tea is a liquid extract of compost obtained by mixing compost and water for a defined period of time. The pig manure and spent mushroom compost were made by steeping compost in water. Compost tea was aerated from 24 hours and molasses and kelp were added as supplements. The four types of compost were tested growth of lettuce. EC of animal manure compost tea was higher than that of spent mushroom compost tea. Mineral nutrients were significantly higher in animal manure compost tea compared with spent mushroom compost tea. Compost tea contains nutrient and a ranges of different organisms. The beneficial fungi and actinomycetes were prominent in a spent mushroom compost tea. Compost tea from animal manure had the higher numbers of total bacteria. The actinomycetes densities were high in spent mushroom compost tea. But actinomycetes were not founded in animal manure compost tea. The growth characteristics of lettuce in animal manure compost tea were higher than those of spent mushroom compost tea. And also SPAD value in leaf was high in plot treated with animal manure compost tea. The fresh yield of lettuce in animal compost tea was higher by 181% that of control plot. The effect of compost tea on growth of lettuce was largely attributable to mineral nutrient.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
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• pp.126-131
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• 2005

Richadella dulcifica, a native shrub in tropical West Africa, gives red berries that have the unusual property of modifying a sour taste into a sweet taste. The red berries contain a taste-modifying protein named miraculin. A synthetic gene encoding miraculin was placed under the control of constitutive promoters and transferred to lettuce. High expression of miraculin was obtained, with accumulation of up to 1% total soluble protein in lettuce leaf. In addition, the miraculin expressed in lettuce possesses a taste-modifying activity.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2003년도 춘계 수산관련학회 공동학술대회발표요지집
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• pp.279-280
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• 2003

Although it has been known though many morphological and physiological studies, its genetic diversity and population structure have not yet been investigated in this species. Therefore, detailed studies, in particular at the DNA level, on genetic diversity of natural populations of wild sea lettuce, and genetic relationships between natural sea lettuce and cultivated sea lettuce are necessary from the viewpoint of plant evolution. (omitted)

• 한국식품영양과학회지
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• 제36권7호
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• pp.932-937
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• 2007

양상추의 계절별(봄, 여름, 가을) 품질 차이 여부를 알아보기 위하여 일반성분, 색차, 클로로필, vitamin C 및 조직감을 측정하였으며 또한 양상추의 위해요소를 알아보기 위하여 48종의 잔류 농약을 측정하였다. 가식부 중량은 여름(953.40 g)>봄(912.27 g)>가을(895.28 g)에 수확한 양상추 순으로 나타났지만 당도는 봄에 수거한 시료가 가장 높게 측정되었다. 전체적인 색은 여름 양상추가 가장 밝은 색을 나타내었고, 다른 계절과 비교하여 가을 양상추는 노란 빛이 뚜렷하고 녹색 빛은 적은 것으로 나타났다. 무기질 함량은 가을에 수거된 시료에 가장 많이 함유되어 있었으며 또한 계절에 관계 없이 전체적으로는 칼륨 함량이 다른 무기성분에 비해 전체적으로 높게 측정되었다. 시료의 항산화능을 유추할 수 있는 chlorophyll과 vitamin C는 봄, 가을에 수거한 시료가 여름에 수거한 시료보다 높게 측정되어 전반적으로 여름에 수거한 양상추가 중량은 크지만 품질 면에서는 약간 떨어진 것으로 판단되어진다. 또한 계절별 양상추에서 검출되어진 잔류 농약은 chlorthalonil이었지만 그 양은 매우 미미하다고 판단되어진다.

• The Plant Pathology Journal
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• 제30권1호
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• pp.90-95
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• 2014

This study was conducted to evaluate the resistance of 212 accessions of lettuce germplasm to gray mold disease caused by Botrytis cinerea. The lettuce germplasm were composed of five species: Lactuca sativa (193 accessions), L. sativa var. longifolia (2 accessions), L. sativa var. crispa (2 accessions), L. saligna (2 accessions), and L. serriola (1 accession); majority of these originated from Korea, Netherlands, USA, Russia, and Bulgaria. After 35 days of spray inoculation with conidial suspension ($3{\times}10^7$ conidia/ml) of B. cinerea on the surface of lettuce leaves, tested lettuce germplasm showed severe symptoms of gray mold disease. There were 208 susceptible accessions to B. cinerea counted with 100% of disease incidence and four resistant accessions, IT908801, K000598, K000599, and K021055. Two moderately resistant accessions of L. sativa, K021055 and IT908801, showed 20% of disease incidence of gray mold disease at 45 days after inoculation; and two accessions of L. saligna, K000598 and K000599, which are wild relatives of lettuce germplasm with loose-leaf type, showed complete resistance to B. cinerea. These four accessions are candidates for breeding lettuce cultivars resistant to gray mold disease.

• Journal of Biosystems Engineering
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• 제40권1호
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• pp.89-93
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• 2015

Purpose: Machine vision-based image processing methods can be useful for estimating the fresh weight of plants. This study analyzes the ability of two different image processing methods, i.e., morphological and pixel-value analysis methods, to measure the fresh weight of lettuce grown in a closed hydroponic system. Methods: Polynomial calibration models are developed to relate the number of pixels in images of leaf areas determined by the image processing methods to actual fresh weights of lettuce measured with a digital scale. The study analyzes the ability of the machine vision- based calibration models to predict the fresh weights of lettuce. Results: The coefficients of determination (> 0.93) and standard error of prediction (SEP) values (< 5 g) generated by the two developed models imply that the image processing methods could accurately estimate the fresh weight of each lettuce plant during its growing stage. Conclusions: The results demonstrate that the growing status of a lettuce plant can be estimated using leaf images and regression equations. This shows that a machine vision system installed on a plant growing bed can potentially be used to determine optimal harvest timings for efficient plant growth management.

• Mycobiology
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• 제30권1호
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• pp.41-46
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• 2002

Composite vegetable crops grown in greenhouses and open fields in Korea were surveyed from 1995 to 1999. Occurrence of Sclerotinia rot was observed in 123 of 277 lettuce fields, in 11 of 18 head lettuce fields, in 12 of 14 endive fields, and in 4 of 38 garland chrysanthemum fields surveyed during the growing seasons. The disease most severely occurred up to 80% on lettuce. Incidence of the disease was as high as 20% at its maximum on endive and garland chrysanthemum but relatively low on head lettuce. Symptoms of the disease developed on leaves of all the composites, crowns of lettuce and head lettuce, and stems of garland chrysanthemum. Out of 240 isolates of Sclerotinia species obtained from the diseased composites, 169 isolates were identified as Sclerotinia sclerotiorum, and the others as S. minor based on their morphological and cultural characteristics. S. sclerotiorum was isolated from all the composites, and S. minor only from lettuce and endive. Eight isolates of S. sclerotiorum and four isolates of S. minor were tested for their pathogenicity to the composites by artificial inoculation. All the isolates of the two Sclerotinia spp. induced rot symptoms on the plants of the composites by artificial inoculation, which were similar to those observed in the fields. The pathogenicity tests revealed that there is no significant difference in virulence of the isolates to the composites and in susceptibility of the composites to the isolates.