Chemical composition and physical characteristics of water caltrop during growth

Abstract

[[abstract]]BACKGROUND: The aim of this study was to monitor the chemical composition and physical and morphological characteristics of two varieties of water caltrop during growth in order to determine the optimal harvesting time. RESULTS: The dry matter, starch and amylose contents and alpha-amylase activity of fruits of both water caltrop varieties increased during the growth period. Mature fruits contained 142-156 g starch kg(-1) fresh sample and provided 684-697 kcal total energy kg(-1) fresh sample. Dry matter content and bulk density increased significantly from 67 to 207 g kg(-1) and from 0.57 to 1.58 g ml(-1) respectively as growth progressed. Morphological analysis showed that the size and number of starch granules increased as growth progressed. Moreover, both varieties contained substantial amounts of essential amino acids, most of which appeared to be superior to the FAO/WHO reference pattern. CONCLUSION: According to the chemical composition and physical characteristics of water caltrop determined in this study, the optimal harvesting time is 42 days after fruit development. (C) 2009 Society of Chemical Industr