Effect of Cooking on the Oxalate Content of Selected Thai Vegetables
- 1 Agro-Industry Department, Faculty of Agriculture and Technology, Rajamangala University of Technology Isan, Surin Campus, Na- khon Ratchasima, Thailand;
- 2 Food Group, Agriculture and Life Sciences, Lincoln University, Canterbury, New Zealand.
- 3 Agro-Industry Department, Faculty of Agriculture and Technology, Rajamangala University of Technology Isan, Surin Campus, Na- khon Ratchasima, Thailand
- 4 Food Group, Agriculture and Life Sciences, Lincoln University, Canterbury, New Zealand.
Abstract
Total and soluble oxalate content levels were measured in thirteen selected vegetables purchased from a local market in Surin Province in the northeast of Thailand. Total oxalate contents of the leaves, shoots and roots of the fresh vegetables ranged from 249.5 ± 12.1 to 7597.9 ± 77.6 mg oxalate/100g dry matter (DM) while soluble oxalate content ranged from 205.0 ± 2.3 to 2677.6 ± 19.0 mg oxalate/100 g DM. Very high levels of total oxalates were found in three of the selected Thai vegetables, Polygonum odoratum (7597.9 ± 77.6 mg/100g DM), Piper aurantaucum (7026.6 ± 76.9 mg/100g DM) and Limnophila aromatic (6179.0 ± 23.6 mg/100g DM). However, the soluble oxalate content of L. aromatic was low and the highest soluble oxalate contents of fresh vegetables were found in P. odoratum , P. aurantuacum and Neptunia oleracea at 2677.6 ± 19.0, 2152.2 ± 65.3 and 1640.8 ± 3.4 mg/100g DM, respectively. Boiling the vegetables reduced the soluble oxalate content between 30.4 and 65.0%. The insoluble oxalate levels increased in eleven of the cooked vegetables while small decreases were observed in L. aromatic and N. oleracea .
- G. P. Savage, L. Vanhanen, S. L. Mason and A. B. Ross, “Effect of Cooking on the Soluble and Insoluble Oxalate Content of Some New Zealand Foods,” Journal of Food Composition and Analysis, Vol. 13, No. 3, 2000, pp. 201-206. doi:10.1006/jfca.2000.0879
- S. Noonan and G. P. Savage, “Oxalate Content of Foods and Its Effect on Humans,” Asia Pacific Journal of Clinical Nutrition, Vol. 8, No. 1, 1999, pp. 64-74. doi:10.1046/j.1440-6047.1999.00038.x
- L. Massey, “Dietary Influences on Urinary Oxalate and Risk of Kidney Stones,” Frontiers in Bioscienes, Vol. 8, 2003, pp. 584-594. doi:10.2741/1082
- W. Chai and M. Liebman, “Effect of Different Cooking Methods on Vegetable Oxalate Content,” Journal of Agricultural Food Chemistry, Vol. 53, No. 8, 2005, pp. 3027-3030.
- T. S. Simpson, G. P. Savage, R. Sherlock and L. P. Vanhanen, “Oxalate Content of Silver Beet Leaves (Beta vulgaris var. cicla) at Different Stages of Maturation and the Effect of Cooking with Different Milk Sources,” Journal of Agricultural and Food Chemistry, Vol. 57, No. 22, 2009, pp. 10804-10808. doi:10.1021/jf902124w
- K. Judprasong, S. Charoenkiatkul, P. Sungpuag, K. Vasanachitt and Y. Nakjamanong, “Total and Soluble Oxalate Contents in Thai Vegetables, Cereal Grains and Legume Seeds and Their Changes after Cooking,” Journal of Food Composition and Analysis, Vol. 19, No. 4, 2006, pp. 340-347. doi: org/10.1016/j.jfca.2005.04.002
- L. Vanhanen, G. P. Savage and C. Sangketkit, “Oxalate Content of Eleven Indigenous Thai Plants,” Journal of Food, Agriculture & Environment, Vol. 9, 2011, pp. 7-9.
- M. Brogren and G. P. Savage, “Bioavailability of Soluble Oxalate from Spinach Eaten with and without Milk Products,” Asia Pacific Journal of Clinical Nutrition, Vol. 12, No. 2, 2003, pp. 219-224.
- G. P. Savage, V. Nilzen, K. Osterberg and L. Vanhanen, “Soluble and Insoluble Oxalate Content of Mushrooms,” International Journal of Food Sciences and Nutrition, Vol. 53, No. 4, 2002, pp. 293-296.
- M. S. Akhtar, B. Israr, N. Bhatty and A. Ali, “Effect of Cooking on Soluble and Insoluble Oxalate Contents in Selected Pakistani Vegetables and Beans,” International Journal of Food Properties, Vol. 14, 2010, pp. 241-249.
- W. D. Holloway, M. E. Argall, W. T. Jealous, J. A. Lee and J. H. Bradbury, “Organic Acids and Calcium Oxalate in Tropical Root Crops,” Journal of Agricultural Food Chemistry, Vol. 37, No. 2, 1989, pp. 337-341. doi:10.1021/jf00086a014