Premium
Effect of nitrogen source in the fertilizing solution on nutritional quality of three members of the Portulaca oleracea aggregate
Author(s) -
Szalai Gabriella,
Dai Nir,
Danin Avinoam,
Dudai Nativ,
Barazani Oz
Publication year - 2010
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.4049
Subject(s) - nitrate , portulaca , chemistry , ascorbic acid , malic acid , food science , oxalic acid , biomass (ecology) , agronomy , bran , botany , citric acid , biology , biochemistry , raw material , organic chemistry
BACKGROUND: Portulaca oleracea (purslane) is nutritious but, in addition to the essential α‐linolenic acid, vitamin C and tocopherols, it contains undesirable oxalic acid. Knowing the effects of nitrate and ammonium on oxalate accumulation, we tested the agronomic potential of three members of the P. oleracea aggregate under various nitrogen fertilization conditions, by measuring biomass production and accumulation of fatty acids, organic acids and tocopherol in the commercial P. sativa ( Pos ) and two natural members: P. nitida ( Pon ) and P. papillato‐stellulata ( Pop ). RESULTS: With nitrate as the sole N source, we measured differences between Pon and Pos in concentrations of the essential ω‐3 fatty acid α‐linolenic acid. Pos also gained less dry biomass under these conditions, implying a higher agronomical and nutritional value for Pon . Increasing the fertilizer ammonium concentration and reducing that of nitrate significantly decreased oxalic acid by factors of up to 1.7, 2.6 and 3.4 in Pos, Pop and Pon , respectively, significantly increased concentrations of tocopherol and malic acid, had no effect on fatty acids or ascorbic acid, but reduced biomass. CONCLUSION: In spite of the recumbent growth habit of Pon , the present findings indicate its agronomic potential. Because early flowering and seed production may be the limiting factors in purslane agriculture, growing Pon in nitrate‐poor conditions might be agriculturally favorable. Copyright © 2010 Society of Chemical Industry