Impact of geographical variation on proximate composition of Sesbania grandiflora L. in Sri Lanka

Abstract

Sesbania grandiflora L. is a widely consumed green leafy vegetable in Sri Lanka, valued for its nutritional and therapeutic benefits. The nutrient composition can vary depending on many factors, including the geographical location. This study investigated the variation in proximate composition of S. grandiflora L. leaves collected from 16 locations across diverse agro-climatic zones in Sri Lanka, focusing on moisture,ash, protein, fat, carbohydrate, and fibre content. Samples were collected, cultivated under organic farming practices, and analysed using standard AOAC methods, methods of analysis established by the AOAC International (formerly the Association of Official Analytical Chemists). One-way ANOVA followed by Tukey post hoc test revealed significant differences (p < 0.05) in nutrient composition among the locations. Moisture content ranged from 64.13% to 82.79%, with both extremes recorded within the low-country wet zone, indicating substantial micro-environmental influence. Ash content varied from 1.89% to 5.68%, reflecting differences in mineral availability across soils. The highest protein content was recorded in the low-country dry zone (16.38%). Carbohydrate and fibre content were notably high in the low-country wet zone, with values reaching 18.33% and 11.79%, respectively. The findings highlight the influence of geographical location on the nutritional quality of S. grandiflora L. This study provides valuable insights for optimising the cultivation of S. grandiflora, contributing to improved dietary planning and region-specific agricultural practices in Sri Lanka.