Nutritional quality of ten leafy vegetables harvested at two light intensities

• Published in: Food chemistry 2016-05, Vol.199, p.702-710
• Main Authors: Colonna, Emma, Rouphael, Youssef, Barbieri, Giancarlo, De Pascale, Stefania
• Format: Article
• Language: English
• Subjects: Antioxidant activity; Ascorbic acid; Baby leaf; Light; Light intensity at harvest; Mineral composition; Nitrate; Nitrates - analysis; Nutritive Value; Phenols - analysis; Plant Leaves - chemistry; Vegetables - chemistry
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2015.12.068

•The impact of ten leafy vegetables and the light intensity at harvest was explored.•Rocket vegetable leaf showed the highest proteins, P, K, Ca and nitrate contents.•Total phenols in red lettuce was high.•Proteins, K, Ca, Mg contents and antioxidant activities were enhanced at high PAR. The nutritional composition of ten leafy vegetables (chicory, green lettuce, lamb’s lettuce, mizuna, red chard, red lettuce, rocket, spinach, Swiss chard, and tatsoi) and quality traits of the selected leafy vegetables in relation to the light intensity (low and high Photosynthetically Active Radiation; PAR) at time of harvest were determined. Irrespective of the light intensity at time of harvest, the highest leaf dry matter (DM), proteins, nitrate, P, K and Ca contents were observed in rocket followed by mizuna. The highest lipophilic antioxidant activity (LAA) was recorded in red lettuce and rocket, whereas ascorbic acid (AA) and total phenolic (TP) contents of red lettuce were higher compared to the other leafy vegetables. When leafy vegetables were harvested at low as opposed to high PAR, the leaf content was higher in DM, protein, K, Ca and Mg, hydrophilic antioxidant activity (HAA), and LAA by 12.5%, 10.0%, 12.6%, 23.7%, 14.1%, 11.9%, and 18.5%, respectively. The highest values in TP for chicory, green lettuce, lamb’s lettuce, mizuna, red chard, and red lettuce, were observed under high PAR.