Hindawi Publishing Corporation Journal of Nutrition and Metabolism Volume 2011, Article ID 584832, 6 pages doi:10.1155/2011/584832 Research Article Relationship between Processing Method and the Glycemic Indices of Ten Sweet Potato (Ipomoea batatas ) Cultivars Commonly Consumed in Jamaica Perceval S. Bahado-Singh, 1, 2, 3 Cliff K. Riley, 3, 4 Andrew O. Wheatley, 1, 2 and Henry I. C. Lowe 3 1 Department of Basic Meidcal Sciences, University of the West Indies, Mona Campus, Jamaica 2 Biotechnology Center, University of the West Indies, Mona Campus, Jamaica 3 Bio-Tech R&D Institute, Kingston, Jamaica 4 College of Health Sciences, University of Technology, Kingston, Jamaica Correspondence should be addressed to Perceval S. Bahado-Singh, perceval.bahadosingh@gmail.com Received 16 June 2011; Revised 19 September 2011; Accepted 24 September 2011 Academic Editor: C. S. Johnston Copyright © 2011 Perceval S. Bahado-Singh et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. This study investigated the effect of different traditional cooking methods on glycemic index (GI) and glycemic response of ten Sweet potato (Ipomoea batatas) cultivars commonly eaten in Jamaica. Matured tubers were cooked by roasting, baking, frying, or boiling then immediately consumed by the ten nondiabetic test subjects (5 males and 5 females; mean age of 27 ± 2 years). The GI varied between 41 ± 5–93 ± 5 for the tubers studied. Samples prepared by boiling had the lowest GI (41 ± 5–50 ± 3), while those processed by baking (82 ± 3–94 ± 3) and roasting (79 ± 4–93 ± 2) had the highest GI values. The study indicates that the glycemic index of Jamaican sweet potatoes varies significantly with the method of preparation and to a lesser extent on intravarietal differences. Consumption of boiled sweet potatoes could minimize postprandial blood glucose spikes and therefore, may prove to be more efficacious in the management of type 2 diabetes mellitus. 1. Introduction Sweet potatoes (Ipomoea batatas) are ranked as the seventh most commonly consumed carbohydrate-rich food source in the world [1] and one of the most important food crop in developing countries after rice, wheat, maize, and cassava [2]. It is a high yielding economic crop with over 90% of global production cultivated in developing countries. Compared to other crops, sweet potato is considered to be a superfood, with high nutritional value [3] and may be a better choice for consumption compared to potatoes (Solanum tuberosum). In the Caribbean, Jamaica is the leading producer of sweet potatoes. It is a major component of the Jamaican diet, where over 95% of the annual production (25,797,000 kg) is consumed locally as a source of digestible carbohydrate [4]. It is estimated that over 50% of the population (1.35 million) consume sweet potato at least once per week as part of their diet in a boiled, roasted, fried, or baked form. However, despite a dietary preference for sweet potatoes in Jamaica and other Caribbean countries, studies have indi- cated that complex carbohydrate-rich foods may have high glycemic indices resulting in potential harmful health effects [5–7] and the development of chronic diseases. Excess con- sumption of high glycemic index foods can lead to hyperin- sulinemia, insulin resistance, weight gain, and possibly obes- ity, leading to insulin-resistant syndrome [8–10]. Recent stu dies have shown a positive correlation between the consump- tion of foods with high glycemic index and increased risk of chronic diseases such as type 2 diabetes, cardiovascular dis- eases, and cancer [11, 12]. Other studies have shown that not all complex carbohyd- rate-rich foods have high glycemic index [13, 14]. In contrast, foods with a low glycemic index can be beneficial in reducing the incidences of chronic diseases [13, 15]. Despite the name, sweet potato may be beneficial to persons with type 2