scholarly journals Effect of Reduced Nitrogen and Supplemented Amino Acids Nutrient Solution on the Nutritional Quality of Baby Green and Red Lettuce Grown in a Floating System

Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 922 ◽  
Author(s):  
Pavlos Tsouvaltzis ◽  
Dimitrios S. Kasampalis ◽  
Danai-Christina Aktsoglou ◽  
Nikolaos Barbayiannis ◽  
Anastasios S. Siomos

Excessive nitrogen fertilization results in nitrate accumulation in leafy vegetables. Reducing the dose of mineral nitrogen or using alternate fertilizers lowers the nitrate accumulation; however, a critical minimum level of mineral nitrogen is necessary to maintain yield and nutritional quality. The aim of this study was to evaluate the effect of two levels of mineral nitrogen (100% and 50%) and three levels of an amino acid solution (0, 0.3, and 0.9%) in the nutrient solution of two baby lettuce cultivars (green and red) grown in a floating system. Nitrogen reduction did not affect yield (12.9–13.4 and 11.0–11.3 g/plant, respectively) but reduced nitrate accumulation (by 43 and 19%, respectively) in both green and red lettuce, while enhancing phenolic content (by 28%) and antioxidant capacity (by 69%) in green lettuce and soluble solid (by 7%) and total chlorophyll content (by 9%) in red lettuce. Although nitrate accumulation was prevented (< 355 mg/kg FW) and most nutritional components increased in both lettuce types by amino acids supplementation, plant growth was negatively affected, especially in red lettuce, in both concentrations of amino acids (reduction by 9 and 35% in 0.3 and 0.9%, respectively). In both lettuce types, proline content increased by 0.9% amino acids supplementation (by 45%), implying a probable induction of a stress condition. Mineral nutrients were slightly affected by nitrogen reduction, which was probably perceived as an abiotic stress.

Agronomy ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 171 ◽  
Author(s):  
Alessandra Moncada ◽  
Alessandro Miceli ◽  
Leo Sabatino ◽  
Giovanni Iapichino ◽  
Fabio D’Anna ◽  
...  

Molybdenum (Mo) is required in enzymes involved in a number of different metabolic processes, and is crucial for the survival of plants and animals. The influence of nutrient solutions containing four levels of molybdenum (0, 0.5, 1.5, and 3.0 µmol/L) on growth, yield, and quality of lettuce, escarole, and curly endive grown in a hydroponic floating system was evaluated. Biometric, nutrient, and quality analyses were conducted to assess the response of each species to Mo. The results demonstrated that molybdenum is essential for harvesting marketable plants. Lettuce, escarole, and curly endive plants differed significantly in their response to molybdenum fertilization. The increase of Mo concentration in the nutrient solution was not harmful for plants and had no influence on yield and morphological traits of the leafy vegetables; however, it significantly affected some quality characteristics. Mo fertilization raised the nutritional quality by increasing ascorbic acid content up to 320.2, 139.0, and 102.1 mg kg−1 FW (fresh weight), and reducing nitrate content down to 1039.2, 1047.3, and 1181.2 mg kg−1 FW for lettuce, escarole, and curly endive, respectively. The addition of Mo in the nutrient solution increased the Mo content of plants up to 0.50, 4.02, and 2.68 μg g−1 FW for lettuce, escarole, and curly endive, respectively. Increasing Mo supply to lettuce, escarole, and curly endive up to 3.0 µmol L−1 could lead to a higher nutritional quality with no significant morphological alteration or yield loss.


2012 ◽  
Vol 461 ◽  
pp. 13-16 ◽  
Author(s):  
Shi Wei Song ◽  
Guo Xiu Liao ◽  
Hou Cheng Liu ◽  
Guang Wen Sun ◽  
Ri Yuan Chen

Effect of ammonium and nitrate ratio (0:100, 25:75, 50:50 and 75:25) on nutritional quality of Chinese kale (Brassica alboglabra Bailey) with 3 cultivars were studied in hydroponics. The results indicated that, the Vitamin C content in product organ (leaf and stalk) of Chinese kale was decreased by the enhancement of ammonium in nutrient solution, and the decrease was not significant for 25% enhancement of ammonium. 25% ammonium enhancement increased the soluble sugar content in product organ significantly, compared with other treatments. Free amino acids and protein content of Chinese kale increased gradually with the increasing of ammonium proportion in nutrient solution. Integrated nutritional quality of Chinese kale in 25% ammonium enhancement treatment was better than others under hydroponics condition.


2008 ◽  
Vol 22 (4) ◽  
pp. 377-397 ◽  
Author(s):  
Ariane Vendemiatti ◽  
Renato Rodrigues Ferreira ◽  
Luiz Humberto Gomes ◽  
Leonardo Oliveira Medici ◽  
Ricardo Antunes Azevedo

2019 ◽  
Vol 126 ◽  
pp. 78-84 ◽  
Author(s):  
I. Maseko ◽  
B. Ncube ◽  
T. Mabhaudhi ◽  
S. Tesfay ◽  
V.G.P. Chimonyo ◽  
...  

2008 ◽  
pp. 1167-1176 ◽  
Author(s):  
A. Alberici ◽  
E. Quattrini ◽  
M. Penati ◽  
L. Martinetti ◽  
P. Marino Gallina ◽  
...  

2006 ◽  
Vol 9 (7) ◽  
pp. 846-850 ◽  
Author(s):  
BE Mikkelsen ◽  
M Bruselius-Jensen ◽  
JS Andersen ◽  
A Lassen

AbstractObjectiveThe present study aimed to investigate whether organic conversion in catering has positive effects on the nutritional quality of menus offered.DesignThe methodology was based on a self-administered questionnaire. The self-declared priority given to the use of organic foods was measured as the basis for assigning catering managers to one of two groups: ‘green’ or ‘non-green’ caterers. These groups were then compared with regard to the relative nutritional quality of the menu options offered to customers.SettingThe study was carried out among randomly selected Danish worksite catering outlets.SubjectsThe subjects participating in the study comprised 526 Danish worksite catering managers.ResultsThe results showed a strong correlation between caterers' ‘green-ness’ and the nutritional quality of the menu options offered. Green caters had more healthy options in their menus than non-green caters, which is likely to result in improved nutritional quality of the diets of end consumers. The reason for this may partly be the increased service training efforts that green caterers practise in order to be able to implement organic foods successfully. It may also be associated with the fact that the price premiums and availability of the organic products forces caterers to serve menus with higher amounts of root and non-green leafy vegetables, pulses and seasonal vegetables.ConclusionThe present findings suggest that organic conversion of public canteens may be a good opportunity to promote healthier eating in public catering.


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