Nutritional quality of greenhouse lettuce at harvest and after storage in relation to N application and cultivation season

dc.contributor.author	Κωνσταντοπούλου, Ελένη	el
dc.contributor.author	Καπότης, Γιώργος	el
dc.contributor.author	Σαλάχας, Γεώργιος	el
dc.contributor.author	Πετρόπουλος, Σπυρίδων Α.	el
dc.contributor.author	Καραπάνος, Ιωάννης Χ.	el
dc.date.accessioned	2015-05-18T15:06:10Z
dc.date.available	2015-05-18T15:06:10Z
dc.date.issued	2015-05-18
dc.identifier.uri	http://hdl.handle.net/11400/10657
dc.rights	Αναφορά Δημιουργού-Μη Εμπορική Χρήση-Όχι Παράγωγα Έργα 3.0 Ηνωμένες Πολιτείες	*
dc.rights.uri	http://creativecommons.org/licenses/by-nc-nd/3.0/us/	*
dc.source	http://www.sciencedirect.com/science/article/pii/S0304423810000993	en
dc.subject	Nitrogen
dc.subject	Ascorbic acid
dc.subject	Άζωτο
dc.subject	Ασκορβικό οξύ
dc.title	Nutritional quality of greenhouse lettuce at harvest and after storage in relation to N application and cultivation season	en
heal.type	journalArticle
heal.classification	Technology
heal.classification	Energy
heal.classification	Τεχνολογία
heal.classification	Ενέργεια
heal.classificationURI	http://zbw.eu/stw/descriptor/10470-6
heal.classificationURI	http://zbw.eu/stw/descriptor/14175-2
heal.classificationURI	N/A-Τεχνολογία
heal.classificationURI	N/A-Ενέργεια
heal.keywordURI	http://lod.nal.usda.gov/12866
heal.contributorName	Passam, Harold C.	en
heal.identifier.secondary	doi:10.1016/j.scienta.2010.03.003
heal.language	en
heal.access	campus
heal.recordProvider	Τ.Ε.Ι Αθήνας. Σχολή Τεχνολογικών Εφαρμογών. Τμήμα Μηχανικών Ενεργειακής Τεχνολογίας Τ.Ε.	el
heal.publicationDate	2010
heal.bibliographicCitation	Konstantopoulou, E., Kapotis, G., Salachas, G., Petropoulos, S., Karapanos, I., et al. (June 2010). Nutritional quality of greenhouse lettuce at harvest and after storage in relation to N application and cultivation season. Scientia Horticulturae. 125(2). pp. 93.e1–93.e5. Elsevier B.V: 2010. Available from: http://www.sciencedirect.com/science/article/pii/S0304423810000993 [Accessed 10/04/2010]	en
heal.abstract	The effect of five levels of nitrogen fertilization on the growth and nutritional quality of Cos lettuce (Lactuca sativa L. cv. Parris Island) at harvest and after storage was studied during autumn and winter in South-West Greece. Plants were cultivated hydroponically in a greenhouse and the nitrate, chlorophyll and ascorbic acid (vitamin C) concentrations within the plant tissues were measured at harvest and following storage at 5 or 10 °C for 10 days. Nitrate accumulated in the leaves with increasing amounts of N within the nutrient solution and was higher in the winter than in the autumn. At the lowest N level (20 mg L−1), the inner leaves accumulated more nitrate than the outer leaves, whereas at higher N levels (140, 200 or 260 mg L−1) nitrate accumulation was higher in the outer leaves. Overall, the highest nitrate concentrations were detected in the petiole and the proximal end of the leaf, but at the lowest N application rate (20 mg L−1) nitrate accumulated in the distal region of the leaf too. Although the nitrate concentrations within the leaves did not change significantly during 10 days storage at 5 or 10 °C, the chlorophyll and vitamin C concentrations decreased. Chlorophyll loss was higher in lettuce that was grown under low N levels and was higher at 10 °C than at 5 °C, but was reduced by enclosure of the lettuce in polyethylene film. It is concluded that the optimum N application rate for Cos lettuce grown hydroponically under cover during autumn and winter in South-West Greece, and in other areas with a similar climate, is 200 mg N L−1 because at this N rate yield is satisfactory and leaf nitrate concentrations are below the maximum acceptable level for human consumption. Nutritional value (vitamin C concentration) and market quality (chlorophyll content) are highest at harvest and decrease during storage, but quality in terms of nitrate concentration does not change.	en
heal.publisher	Elsevier B.V.	en
heal.journalName	Scientia Horticulturae	en
heal.journalType	peer-reviewed
heal.fullTextAvailability	true