Fresh-cut lettuce is widely used in ready-to-eat salads sold in modified atmosphere packages (MAP).Even in MAP,fresh-cut lettuce has short shelf life that results in loss of nutrients.Lettuce cultivars exhibit genetic...Fresh-cut lettuce is widely used in ready-to-eat salads sold in modified atmosphere packages (MAP).Even in MAP,fresh-cut lettuce has short shelf life that results in loss of nutrients.Lettuce cultivars exhibit genetic variation for shelf life in MAP,but their variation for nutrient retention is not known.Fifty accessions were evaluated for initial content of ascorbic acid (AsA),carotenoids,and sugars and their retention in storage.Accessions with high content and/or good retention of one or more nutrients were identified.The romaine accession ‘Floricos’ had high levels of all the three nutrients.Accessions with relatively high retention of all the three nutrients were ‘Salinas 88’,‘Siskiyou’,‘Solar’,SM09A,‘Romance’,and ‘Green Towers’.Romaine cultivars,‘Balady Barrage’,‘Green Towers’,and ‘Darkland’ had relatively high initial levels of all tested nutrients and good rate of their retention.There was no clear correlation between initial AsA/carotene concentrations and their retention rates,suggesting that besides content,retention of nutrients should also be a breeding target in a lettuce nutritional improvement program.Statistical analyses with the Pearson's correlation coefficient determined a negative relationship between tissue deterioration(AUDePS) and retention of all tested nutrients[r of-0.52 (P<0.0001) for AsA,-0.27 (P<0.01) for total carotene,and-0.59 (P<0.0001) for total sugars],suggesting that an increase in tissue deterioration intensifies nutrient decay.Broad-sense heritability (H~2) across the experiments was0.15 for AsA,0.23 for total carotene,and 0.50 for total sugars.Identification of germplasm with high nutrient content,extended shelf life and good nutrient retention provides valuable information for the lettuce industry and associated breeding programs.展开更多
Carotenoids are a group of natural pigments that are isolated from plants and are known for their great importance in maintaining human health. Beta-carotene is an organic compound, from yellow to red-orange colour, w...Carotenoids are a group of natural pigments that are isolated from plants and are known for their great importance in maintaining human health. Beta-carotene is an organic compound, from yellow to red-orange colour, which is found in many plants, fruits and vegetables. All carotenoids, especially beta-carotene, which is the subject of this research, are used in the pharmaceutical, food and cosmetic industries. It is also important in medicine as it prevents the occurrence of many diseases. Beta-carotene is a precursor of vitamin A and is used in various research due to its strong antioxidant effect. The highest amount of beta-carotene is found in carrots, followed by apricots, tomatoes, asparagus, broccoli, pumpkins, plums, etc. This plant pigment was isolated from carrots using a reflux extraction method using the organic solvents methanol and methylene chloride. The isolated carotenoid was confirmed by UV, TLC, FTIR, and HPLC methods. The absorption maxima of the UV spectrum of the isolated compound (β-carotene) range from 200 to 280 nm and 400 to 500 nm. The identification of beta-carotene was done by analysis using the FTIR method, where functional groups that are present indicate the isolated compound. HPLC method is rapid, effective and sensitive for carotenoid analysis. Analysis of the HPLC method confirms the isolated compound with an absorption maximum of 448 nm, which was compared with the standard.展开更多
建立了一种在温和条件下,用可见光催化合成一系列3,4-二氢异喹啉-1(2H)-酮及其衍生物的方法。该方法在室温条件下,以2-烯丙基-N-甲氧基苯甲酰胺为模板底物,以碘化钾作为光催化剂,25 W 460 nm的蓝色LED灯照射下,合成一系列3,4-二氢异喹啉...建立了一种在温和条件下,用可见光催化合成一系列3,4-二氢异喹啉-1(2H)-酮及其衍生物的方法。该方法在室温条件下,以2-烯丙基-N-甲氧基苯甲酰胺为模板底物,以碘化钾作为光催化剂,25 W 460 nm的蓝色LED灯照射下,合成一系列3,4-二氢异喹啉-1(2H)-酮衍生物,最高产率可达到83%。该合成路径具有底物适用范围广、经济实用等特点,为3,4-二氢异喹啉-1(2H)-酮衍生物合成提供了一种经济简便的方法。展开更多
基金supported by the Specialty Crop Block Grant Program of the U.S. Department of Agriculture's (USDA), Agricultural Marketing Service (AMS) through the California Department of Food and Agriculture (SCB15015)partly also by funding from the California Leafy Greens Research Board and by Oak Ridge Institute for Science and Education (ORISE) Research Participation Program。
文摘Fresh-cut lettuce is widely used in ready-to-eat salads sold in modified atmosphere packages (MAP).Even in MAP,fresh-cut lettuce has short shelf life that results in loss of nutrients.Lettuce cultivars exhibit genetic variation for shelf life in MAP,but their variation for nutrient retention is not known.Fifty accessions were evaluated for initial content of ascorbic acid (AsA),carotenoids,and sugars and their retention in storage.Accessions with high content and/or good retention of one or more nutrients were identified.The romaine accession ‘Floricos’ had high levels of all the three nutrients.Accessions with relatively high retention of all the three nutrients were ‘Salinas 88’,‘Siskiyou’,‘Solar’,SM09A,‘Romance’,and ‘Green Towers’.Romaine cultivars,‘Balady Barrage’,‘Green Towers’,and ‘Darkland’ had relatively high initial levels of all tested nutrients and good rate of their retention.There was no clear correlation between initial AsA/carotene concentrations and their retention rates,suggesting that besides content,retention of nutrients should also be a breeding target in a lettuce nutritional improvement program.Statistical analyses with the Pearson's correlation coefficient determined a negative relationship between tissue deterioration(AUDePS) and retention of all tested nutrients[r of-0.52 (P<0.0001) for AsA,-0.27 (P<0.01) for total carotene,and-0.59 (P<0.0001) for total sugars],suggesting that an increase in tissue deterioration intensifies nutrient decay.Broad-sense heritability (H~2) across the experiments was0.15 for AsA,0.23 for total carotene,and 0.50 for total sugars.Identification of germplasm with high nutrient content,extended shelf life and good nutrient retention provides valuable information for the lettuce industry and associated breeding programs.
文摘Carotenoids are a group of natural pigments that are isolated from plants and are known for their great importance in maintaining human health. Beta-carotene is an organic compound, from yellow to red-orange colour, which is found in many plants, fruits and vegetables. All carotenoids, especially beta-carotene, which is the subject of this research, are used in the pharmaceutical, food and cosmetic industries. It is also important in medicine as it prevents the occurrence of many diseases. Beta-carotene is a precursor of vitamin A and is used in various research due to its strong antioxidant effect. The highest amount of beta-carotene is found in carrots, followed by apricots, tomatoes, asparagus, broccoli, pumpkins, plums, etc. This plant pigment was isolated from carrots using a reflux extraction method using the organic solvents methanol and methylene chloride. The isolated carotenoid was confirmed by UV, TLC, FTIR, and HPLC methods. The absorption maxima of the UV spectrum of the isolated compound (β-carotene) range from 200 to 280 nm and 400 to 500 nm. The identification of beta-carotene was done by analysis using the FTIR method, where functional groups that are present indicate the isolated compound. HPLC method is rapid, effective and sensitive for carotenoid analysis. Analysis of the HPLC method confirms the isolated compound with an absorption maximum of 448 nm, which was compared with the standard.
文摘建立了一种在温和条件下,用可见光催化合成一系列3,4-二氢异喹啉-1(2H)-酮及其衍生物的方法。该方法在室温条件下,以2-烯丙基-N-甲氧基苯甲酰胺为模板底物,以碘化钾作为光催化剂,25 W 460 nm的蓝色LED灯照射下,合成一系列3,4-二氢异喹啉-1(2H)-酮衍生物,最高产率可达到83%。该合成路径具有底物适用范围广、经济实用等特点,为3,4-二氢异喹啉-1(2H)-酮衍生物合成提供了一种经济简便的方法。
