V. Diaz, E. Hedren, J. Rueles and U. Svernberg, “Effect of Cell Wall Degrading Enzymes on in Vitro Carotene Bio accessibility in Lactic Acid Fermented Carrot Beverage,” Journal of Food Science, Vol. 69, No. 2, 2004, pp. 136-142.
 H. van den Berg, R. Faulks, H. F. Granado, J. Hirschberg, B. Olmedilla, G. Sandman and W. Stahl, “The Potential for the Improvement of Carotenoid Levels in Foods and the Likely Systemic Effects,” Journal of the Science of Food and Agriculture, Vol.80, No. 7, 2000, pp. 880-912. doi:10.1002/(SICI)1097-0010(20000515)80:7<880::AID-JSFA646>3.0.CO;2-1
 C. Hotz and C. McClafferty, “From Harvest to Health: Challenges for Developing Biofortified Staple Foods and Determining Their Impact on Micronutrient Status,” Food and Nutrition Bulletin, Vol. 28, No. 2, 2007, pp. 1776-1783.
 S. A. Tanumihardjo, H. Bouis, C. Hotz, J. V. Meenakshi and B. McClafferty, “Biofortification of Staple Crops: An Emerging Strategy to Combat Hidden Hunger,” Comprehansive Reviews in Food Science and Food Safety, Vol. 7, No. 4, 2008, pp. 329-334.
 K. Yonekura-Sakakibara and K. Saito, “Review: Genetically Modified Plants for the Promotion of Human Health,” Biotechnology Letters, Vol. 28, No. 24, 2006, pp. 1983-1991. doi:10.1007/s10529-006-9194-4
 S. Chowdhury, J. V. Meenashi, K. I. Tomlins and C. Owori, “Are Consumers in Developing Countries Willing to Pay More for Micronutrient-Dense Biofortified Foods? Evidence from a Field Experiment in Uganda,” American Journal Agricultural Economics, Vol. 93, No. 1, 2011, pp. 83-97.
 P. J. van Jaarsveld, M. Faber, S. A. Tannumihardjo, P. Nestel, J. C. Lombard and A. J. S. Benade, “β-Carotene Rich Orange Fleshed Sweet Potatoes Improve the Vita min A Status of Primary School Children Assessed with the Modified-Relative-Dose-Response Test,” American Journal of Clinical Nutrition, Vol. 81, No. 5, 2005, pp. 1080-1087.
 K. Pillary, J. Derera, M. Siwela and F. J. Veldman, “Con sumer Acceptance of Yellow, Provitamin A-Biofortified Maize in KwaZulu-Natal,” South African Journal of Clinical Nutrition, Vol. 24, No. 4, 2011, pp. 186-191.
 T. Muzhingi, A. S. Langyintuo, L. C. Malaba and M. Banziger, “Consumer Acceptability of Yellow Maize Products in Zimbabwe,” Food Policy, Vol. 33, No. 4, 2008, pp. 352-361. doi:10.1016/j.foodpol.2007.09.003
 H. De Groote and S. C. Kimenju, “Comparing Consumer Preferences for Color and Nutritional Quality in Maize: Application of a Semi-Double Bound Logistic Model on Urban Consumers in Kenya,” Food Policy, Vol. 33, No. 4, 2008, pp. 362-270. doi:10.1016/j.foodpol.2008.02.005
 R. O. M. Mwanga, B. Odongo, C. Niringiye and A. Alajo, “Release of Two Orange-Fleshed Sweet Potato Cultivars, ‘SPK004’ (‘Kakamega’) and ‘Ejumula’, in Uganda,” HortScience, Vol. 42, No. 7, 2007, pp. 1728-1730.
 O. Neidecker-Gonzales, P. Nestel and H. Bouis, “Estimating the Global Costs of Vitamin A Capsule Supplementation: A Review of the Literature,” Food and Nutrition Bulletin, Vol. 28, No. 3, 2007, pp. 307-316.
 J. V. Meenakshi, N. Johnson, V. M. Manyong, H. De Groote, J. Javelosa, D. Yanggen and E. Meng, “How Cost Effective Is Biofortification in Combating Micronutrient Malnutrition? An Exante Assessment,” Harvest Plus Working Paper No. 2, Wasgington DC, 2007.
 J. V. Meenakshi, N. Johnson, V. Manyong, H. DeGroote, J. Javelosa, D. Yanggen, F. Naher, C. Gonzales, J.Garcia and E. Meng, “How Cost-Effective Is Biofortification in Combating Micronutrient Malnutrition? An Exante As sessment,” World Development, Vol. 38 No. 1, 2010, pp. 64-75. doi:10.1016/j.worlddev.2009.03.014
 A. C. BovellBenjamin and L. T. Steve, “Sweetpotato: A Review of Its Past Present and Future Role in Human Nutrition,” Advances in Food Nutrition Research, Vol. 52, 2007, pp. 1-59. doi:10.1016/S1043-4526(06)52001-7
 P. J. van Jaarsveld, M. De Wet, E. Harmse, P. Nestel and D. B. Rodriguez-Amaya, “Retention of B-Carotene in Boiled, Mashed Orange-Fleshed Sweet Potato,” Journal of Food Composition and Analysis, Vol. 19 No. 4, 2006, pp. 321-329. doi:10.1016/j.jfca.2004.10.007
 S. A.Tanumihardjo, “Factors Influencing the Conversion of Carotenoids to Retinol: Bioavailability to Conversion to Bioefficacy,” International Journal of Vitamin Research, Vol. 72, No. 1, 2002, pp. 40-45. doi:10.1024/0300-9822.214.171.124
 J. Low, M. Arimond, N. Osman, B. Cunguara, B. Zano and D. Tschirley, “A Food-Based Approach Introducing Orange-Fleshed Sweet Potatoes Increased Vitamin A Intake and Serum Retinol Concentrations in Young Children in Rural Mozambique,” The Journal of Nutrition, Vol. 137, No. 5, 2007, pp. 1320-1327.
 M. J. Haskell, K. M. Jamil, F. Hassan, J. M. Peerson, M. I. Hossain, G. J. Fuchs and K. H. Brown, “Daily Consumption of Indian Spinach (Basella alba) or Sweet Potatoes Has a Positive Effect on Total Body Vitamin A Stores in Bangladesh Men,” American Journal of Clinical Nutrition, Vol. 80, No. 3, 2004, pp. 705-714.
 A. Bengtsson, A. Namutebi, M. L. Alimnger and U. Svanberg, “Effects of Various Traditional Processing Methods on the All-Trans-β-Carotene Content of Orange Fleshed Sweetpotato,” Journal of Food Composition and Analysis, Vol. 21, No. 2, 2008, pp. 134-143. doi:10.1016/j.jfca.2007.09.006
 J. P. Mills, G. A. Tumuhimbise, K. M. Jamil, S. G. Thak kar, M. L. Failla and S. A. Tanumihardjo, “Sweet Potato b-Carotene Bioefficacy Is Enhanced by Dietary Fat and Not Reduced by Soluble Fiber in Mongolian Gerbils,” Journal of Nutrition, Vol. 139, No. 1, 2009, pp. 44-50. doi:10.3945/jn.108.098947
 X. Ye, S. Al-Babili, A. Kl?ti, J. Zhang, P. Lucca, P. Beyer and I. Potrykus, “Engineering the Provitamin A (Beta Carotene) Biosynthetic Pathway into (Carotenoid-Free) Rice Endosperm,” Science, Vol. 287, No. 5451, 2000, pp. 303-305. doi:10.1126/science.287.5451.303
 J. A. Paine, C. A. Shipton, S. Chaggar, R. M. Howells, M. J. Kennedy, G. Vernon and R. Drake, “Improving the Nutritional Value of Golden Rice through Increased Pro Vitamin A Content,” Nature Biotechnology, Vol. 23, No. 4, 2005, pp. 482-487. doi:10.1038/nbt1082
 G. Tang, Y. Hu, S. A. Yin, G. E. Dallal, M. A. Grusak and R. M. Russel, “β-Carotene in Golden Rice Is as Good as β-Carotene in Oil at Providing Vitamin A to Children,” American Journal of Clinical Nutrition, Vol. 96, No. 3, 2012, pp. 658-664. doi:10.3945/ajcn.111.030775
 G. Tang, J. Qin, G. Dolnikowski, G. R. Russell and M. A. Grusak, “Golden Rice Is an Effective Source of Vitamin A,” American Journal of Clinical Nutrition, Vol. 89, No. 6, 2009, pp. 1776-1783. doi:10.3945/ajcn.2008.27119
 C. Pray, R. Paalberg and L. Unnevehr, “Patterns of Political Response to Biofortified Varieties of Crops Produced with Different Breeding Techniques and Agronomic Traits,” The Journal of Agrobiotechnology Management and Economics, Vol. 10, No. 3, 2007, pp. 135-143.
 T. Muzhingi, T. H. Gadaga, H. Siwela, M. A. Grusak, R. M. Russel and G. Tang, “Yellow Maize with High β-Carotene Is an Effective Source of Vitamin A in Healthy Zimbambean Men,” American Journal of Clinical Nutrition, Vol. 94, No. 2, 2011, pp. 510-519. doi:10.3945/ajcn.110.006486
 S. Li, A. Nugroho, T. Rocheford and W. S. White, “Vi tamin A Equivalence of the β-Carotene in β-Carotene Biofortified Maize Porridge Consumed by Women,” American Journal of Clinical Nutrition, Vol. 92, No. 5, 2010, pp. 1105-1112. doi:10.3945/ajcn.2010.29802
 C. Davis, H. Jing, J. A. Howe, T. Rocheford and S. A. Tanumihardjo, “β-Cryptoxanthin from Supplements or Carotenoid-Enhanced Maize Maintains Liver Vitamin A in Mongolian gerbils (Meriones unguiculatus) Better than or Equal to b-Carotene Supplements,” British Journal of Nutrition, Vol. 100, No. 4, 2008, pp. 786-793. doi:10.1017/S0007114508944123
 M. L. Failla, C. Chitchumroonchokchai, D. Siritunga, F. F. De Moura, M. Fregene, M. J. Manary and R. T. Sayre, “Retention during Processing and Bioaccessibility of β Carotene in High β-Carotene Transgenic Cassava Root,” Journal of Agriculture and Food Chemisty, Vol. 60, No. 15, 2012, pp. 3861-3866. doi:10.1021/jf204958w
 J. A. Howe, B. Maziya-Dixon and S. A. Tanumihardjo, “Cassava with Enhanced Beta-Carotene Maintains Adequate Vitamin A Status in Mongolian gerbils (Meriones unguiculatus) Despite Substantial cis-Isomer Content,” The British Journal of Nutrition, Vol. 102, No. 3, 2009, pp. 342-349. doi:10.1017/S0007114508184720
 M. R. Lafrano, L. R .Woodhouse, D. J. Burnett, B. J. Burri, “Biofortified Cassava Increases β-Carotene and Vitamin A Concentrations in the TAG-Rich Plasma Layer of American Women,” British Journal of Nutrition, First View Article, 2013, pp. 1-11.