Effect of Frozen Storage on the Chemical Stability, Functional and Sensory Properties of ‘Ogbono’ ( Irvingiagarbonensis var. excelsa ) and ‘Egusi’ ( Citrullus vulgaris schrad ) Seed Flours

Abstract

‘Ogbono’ (Irvingiagarbonensis var. excelsa) and ‘egusi’ (Citrullusvulgaries Schrad) seed flours were packaged separately in vacuum sealed high density polyethylene bags of 0.7mm thickness and were subjected to frozen storage by storing the packs in a domestic deep freezer for up to four months. Samples were removed at intervals of 0, 1, 2, 3 and 4 months for analysis. The effects of frozen storage on the shelf-stability factors (moisture, free-fatty acids and peroxide values), selected functional properties of water/oil absorption capacity, foam capacity and viscosity and sensory attributes of the frozen ‘ogbono’ and ‘egusi’ samples were investigated. The result of this investigation shows that there was no significant difference (p>0.05) in storage life (shelf stability factors), selected functional and sensory properties of both “ogbono” and ‘egusi’ seed flours frozen up to three months. However, all the shelf-stability properties, selected functional and sensory properties of both flour samples decreased significantly (p<0.05) after four months of frozen storage. Therefore, frozen storage at -18°C could be used to preserve the storage life, functional and sensory properties of vacuum packaged ‘ogbono’ and ‘egusi’ seed flours up to three months in moisture/gas-impermeable polyethylene packs of 0.7mm thickness without losing its sensory properties.