Effect of Different Drying Methods on the Mineral Content of Three Accessions of Roselle (Hibiscus sabdariffa) Calyces

Abstract

Fresh Roselle (Hibiscus sabdariffa l.) calyces have shorter shelf life due to their high moisture content. In order to extend their shelf life, Roselle calyces are dried. However, the effect of different drying methods on mineral composition are not sufficiently reported. A study was therefore conducted to determine the influence of oven, solar and sun drying methods on the mineral content of three accessions (HS11, HS41 and HS89) of roselle calyces grown in Ghana. A 3×3 factorial experiment laid in Completely Randomized Design (CRD) with three replications was used. The roselle accessions were harvested 12 weeks after planting. Sodium, magnesium, calcium, zinc, potassium, phosphorus and iron were the mineral elements analyzed for using recommended procedures. The study showed that accession HS41 had the highest calcium, iron, potassium, phosphorus and zinc content being (0.98%), (8.36 mg/kg), (0.60%), (0.36%), and (2.34mg/kg) respectively. Accession HS89 had the highest magnesium (0.55%) and sodium content (0.030%). With respect to methods of drying, sun recorded significantly highest calcium (0.81%), iron (6.77mg/kg), magnesium (0. 42%), sodium (0.03%), and zinc content (1.93mg/kg). On the other hand, Oven drying resulted in the highest potassium (0.58%) and phosphorus content (0.34).