Physical Characteristics of Soursop Seeds as affected by Moisture Content

Abstract. Soursop (annona muricata) is an edible fruit which is reported to be potent against cancer and it is commonly found in the mangrove forest area of Nigeria. It is mostly eaten fresh and a potential source of raw material for puree, jam, jelly power fruits bar and flake. This study evaluated some physical, mechanical and oil properties of soursop seeds. Fresh and physiologically matured fruits obtained from the Nigeria Horticultural Research Institute (NIHORT), Ibadan were peeled and processed manually to obtain clean seeds. Seed samples were conditioned to four different moisture content levels of 5.62, 13.51, 17.31 and 21.39% (w.b) using standard methods. Physical properties determined included seed size, sphericity, surface area, porosity, true and bulk densities, Results revealed that significant (p<0.05) differences occurred among dimensional properties which ranged from 15.78 ± 1.00 to 15.98 ± 1.13 mm in the major dimension for 17.31 and 21.39% moisture content respectively while minor diameter was 9.02 ± 0.66 and 6.02 ± 0.48 mm at 17.31 and 21.39% moisture levels respectively. Value for surface area, geometric and arithmetic mean diameters of 293.80±27.08 mm², 28.60 ± 4.46mm and 9.102±1.420mm at 21.39% moisture level were significantly (p<0.05) higher than other moisture levels. Bulk density, true density and porosity were significantly (p < 0.05) affected by moisture content while the angle of repose was not significantly (p > 0.05) affected by the moisture content. The established values of the properties determined would assist engineers and food processors in the design of equipment and machines for handling and post-harvest processing of soursop seeds.