Comparative Study of Ascorbic Acid and Tocopherol Concentrations in Hydroponic- and Soil-Grown Lettuces

Drew N. Buchanan, Stanley T. Omaye

Agriculture, Nutrition and Veterinary Sciences Department, University of Nevada, Reno, USA..

DOI: 10.4236/fns.2013.410136                

Abstract

Hydroponically-grown produce may be a way of helping to feed the world a variety of fruits and vegetables, regardless of soil quality, space availability or climate. The objective of this study was to determine whether hydroponicallygrown lettuce contains as much ascorbic acid and tocopherol as soil-grown lettuce. We analyzed four varieties of lettuce, including: Waldmann’s Dark Green, Red Lollo Antago, Red Romaine Annapolis, and Butterleaf. The tocopherol content of hydroponically-grown Waldmann’s Dark Green, Red Lollo Antago, and Red Romaine Annapolis was 229%, 497% and 492% higher, respectively, compared to their soil-grown counterpart. The ascorbic acid content of hydroponically-grown Waldmann’s Dark Green, Red Lollo Antago, and Red Romaine Annapolis was 93%, 171% and 216% higher, respectively, compared to their soil-grown counterparts. Hydroponically grown lettuce varieties are significantly higher in both ascorbic acid and tocopherol content than their soil-grown counterparts, and hydroponic gardening is a viable option for producing nutritious fruits and vegetables.

Keywords

Hydroponic; Lettuce; Ascorbic Acid; Tocopherol; Leafy Vegetables

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	P. M. Kris-Etherton, K. D. Hecker, A. Bonanome, S. M. Coval, A. E. Binkoski, K. F. Hilpert, et al., “Bioactive Compounds in Foods: Their Role in the Prevention of Cardiovascular Disease and Cancer,” American Journal of Medicine, Vol. 113, No. 9, 2002, pp. 71-88. http://dx.doi.org/10.1016/S0002-9343(01)00995-0
[2]	R. Wheeler, “Plants for Human Life Support in Space: From Myers to Mars,” Gravitational and Space Biology, Vol. 23, No. 2, 2010, pp. 25-35.
[3]	G. F. Combs, “The Vitamins: Fundamental Aspects in Nutrition and Health,” Elsevier, Burlington, 2008.
[4]	I. D. Desai and L. J. Machlin, “Vitamin E. Methods in Vitamin Assay,” 4th Edition, John Wiley & Sons WileyInterscience, New York, 1985, pp. 255-283.
[5]	S. T. Omaye, J. D. Turnbull and H. E. Sauberlich, “Selected Methods for the Determination of Ascorbic Acid in Animal Cells, Tissues, and Fluids,” Methods in Enzymology, Vol. 62, 1979, pp. 7-8. http://dx.doi.org/10.1016/0076-6879(79)62181-X
[6]	C. Sgherri, S. Cecconami, C. Pinzino, F. Navari-Izzo and R. Izzo, “Levels of Antioxidants and Nutraceuticals in Basil Grown in Hydroponics and Soil,” Food Chemistry, Vol. 123, No. 2, 2010, pp. 416-422. http://dx.doi.org/10.1016/j.foodchem.2010.04.058
[7]	S. Nicola, J. Hoeberechts and E. Fontana, “Comparison between Traditional and Soilless Culture Systems to Produce Rocket (Eruca sativa) with Low Nitrate Content,” Acta Horticulturae, Vol. 697, 2005, pp. 549-555.
[8]	M. V. Selma, M. C. Luna, A. Martínez-Sánchez, J. A. Tudela, D. Beltrán, C. Baixauli and M. I. Gil, “Sensory Quality, Bioactive Constituents and Microbiological Quality of Green and Red Fresh-Cut Lettuces (Lactuca sativa L.) Are Influenced by Soil and Soilless Agricultural Production Systems,” Postharvest Biology and Technology, Vol. 63, No. 1, 2012, pp. 16-24. http://dx.doi.org/10.1016/j.postharvbio.2011.08.002
[9]	R. Szymańska and J. Kruk, “Tocopherol Content and Isomers’ Composition in Selected Plant Species,” Plant Physiology and Biochemistry, Vol. 46, No. 1, 2008, pp. 29-33. http://dx.doi.org/10.1016/j.plaphy.2007.10.009
[10]	O. Kenny and D. O’Beirne, “The Effects of Washing Treatment on Antioxidant Retention in Ready-To-Use Iceberg Lettuce,” International Journal of Food Science and Technology, Vol. 44, No. 6, 2009, pp. 1146-1156. http://dx.doi.org/10.1111/j.1365-2621.2009.01935.x
[11]	S. K. Lee and A. A. Kader, “Preharvest and Postharvest Factors Influencing Vitamin C Content of Horticultural Crops,” Postharvest Biology and Technology, Vol. 20, No. 3, 2000, pp. 207-220. http://dx.doi.org/10.1016/S0925-5214(00)00133-2
[12]	A. Mozafar, “Decreasing the NO2 and Increasing the Vitamin C Contents in Spinach by a Nitrogen Deprivation Method,” Plant Foods for Human Nutrition, Vol. 49, No. 2, 1996, pp. 155-162. http://dx.doi.org/10.1007/BF01091973
[13]	M. M. Rahman, M. M. R. Khan and M. M. Hosain, “Analysis of Vitamin C (Ascorbic Acid) Contents in Various Fruits and Vegetables by UV-Spectrophotometry,” Bangladesh Journal of Scientific and Industrial Research, Vol. 42, No. 4, 2007, pp. 417-424.
[14]	M. M. R. Kahn, M. M. Rahman, M. S. Islam and S. A. Begum, “A Simple UV-Spectrophotometric Method for the Determination of Vitamin C Content in Various Fruits and Vegetables at Sylhet Area in Bangladesh,” Journal of Biological Sciences, Vol. 6, No. 2, 2006, pp. 388-392. http://dx.doi.org/10.3923/jbs.2006.388.392
[15]	E. Tütem, R. Apak, E. Günaydi and K. Sozgen, “Spectrophotometric Determination of Vitamin E (α-Tocopherol) Using Copper(II)-Neocuprine Reagent,” Talanta, Vol. 44, No. 2, 1997, pp. 249-255. http://dx.doi.org/10.1016/S0039-9140(96)02041-3
[16]	J. Fabianek, J. DeFilippi, T. Rickards and A. Herp, “Micromethod for Tocopherol Determination in Blood Serum,” Clinical Chemistry, Vol. 14, 1968, pp. 456-462.
[17]	S. Nicola, J. Hoeberechts and E. Fontana, “Comparison between Traditional and Soilless Culture Systems to Produce Rocket (Eruca sativa) with Low Nitrate Content,” Acta Horticulturae, Vol. 697, 2005, pp. 549-555.
[18]	USDA, “Nutrient Data for 11250, Lettuce, Butterhead (Includes Boston and Bibb Types), Raw,” National Agricultural Library, 2012. Ndb.nal.usda.gov/ndb/foods/show/3067
[19]	D. Frezza, A. León, V. Logegaray and A. Chiesa, “Soilless Culture Technology for High Quality Lettuce,” Acta Horticulturae, No. 697, 2005, pp. 43-48.
[20]	G. Coronel, M. Chang and A. Rodríguez-Delfin, “Nitrate Reductase Activity and Chlorophyll Content in Lettuce Plants Grown Hydroponically and Organically,” Acta Horticulturae, No. 843, 2009, pp. 37-143.
[21]	M. R. Broadley, I. Seginer, A. Burns, A. EscobarGutiérrez, I. G. Burns and P. J. White, “The Nitrogen and Nitrate Economy of Butterhead Lettuce (Lactuca savita var. capitata L.),” Journal of Experimental Botany, Vol. 54, No. 390, 2003, pp. 2081-2090. http://dx.doi.org/10.1093/jxb/erg222
[22]	I. Seginer, “A Dynamic Model for Nitrogen-Stressed Lettuce,” Annuls of Botany, Vol. 91, No. 6, 2003, pp. 623635. http://dx.doi.org/10.1093/aob/mcg069
[23]	US-ARS, “Health-Promoting Foods: From ARS to You!” Agricultural Research Magazine, Vol. 56, 2008, Unpaginated.