1. Center for the Studies of Sensory Impairment, Aging, and Metabolism, Guatemala City 01011, Guatemala
2. Center Institute of Nutrition and Food Research, Technische Universitaet Muenchen, Freising D-85354, Germany
3. Department of Human Nutritional Sciences, University of Manitoba, Winnipeg R3T 2N2, Manitoba, Canada
4. Advanced Chemistry Instrumentation Laboratory, Research Institute, Universidad del Valle de Guatemala, 01015 Guatemala