Nutritional Value of Crisphead ‘Iceberg’ and Romaine Lettuces (Lactuca sativa L.)

Moo Jung Kim, Youyoun Moon, Dean A. Kopsell, Suejin Park, Janet C. Tou, Nicole L. Waterland

Abstract


Lettuce (Lactuca sativa L.) is one of the most popular vegetables worldwide, but is often viewed as low in nutritional value. However, lettuce contains health-promoting nutrients and biosynthesis of such phytochemicals varies depending on cultivar, leaf color and growing conditions. Studies of such parameters on the nutritional value have not been conclusive because the lettuce samples were collected from heterogeneous growing conditions and/or various developmental stages. In our study nutritional composition was evaluated in the two most popular lettuce types in Western diets, romaine and crisphead ‘Iceberg’, with red or green leaves grown under uniform cultivating conditions and harvested at the same developmental stage. In the investigated lettuce cultivars, insoluble fiber content was higher (P ≤ 0.05) in romaine than crisphead lettuces. Alpha-linolenic acid (omega-3 polyunsaturated fatty acid) was the predominant fatty acid and was higher in romaine than crisphead. Iron and bone health-promoting minerals (Ca, Mg and Mn) were significantly higher (P ≤ 0.001) in romaine. The content of Beta-carotene and lutein in romaine (668.3 ug g-1 dry weight) was ~45% higher than in crisphead (457.3 ug g-1dry weight). For leaf color comparison, red cultivars provided higher amount of minerals (Ca, P, Mn and K), total carotenoids, total anthocyanins and phenolics than green cultivars. Based on our study results, romaine was generally higher in nutrients analyzed, especially red romaine contained significantly higher amount of total carotenoids, total anthocyanins and phenolics. Therefore, romaine type lettuces with red rather than green leaves may offer a better nutritional choice.


Full Text:

PDF


DOI: http://dx.doi.org/10.5539/jas.v8n11p1

Copyright (c) 2016

Journal of Agricultural Science   ISSN 1916-9752 (Print)   ISSN 1916-9760 (Online)  E-mail: jas@ccsenet.org

Copyright © Canadian Center of Science and Education

To make sure that you can receive messages from us, please add the 'ccsenet.org' domain to your e-mail 'safe list'. If you do not receive e-mail in your 'inbox', check your 'bulk mail' or 'junk mail' folders.