Foaming and foam mat drying characteristics of ripe banana [Musa balbisiana (BB)] pulp

Foam-mat drying characteristics of wild ripe banana [Musa balbisiana (BB)] pulp on the attributes of the product were investigated. The effects of pulp concentration (PC), skim milk powder (SMP) and whipping time (WT) on foaming characteristics such as foam density, drainage volume and foam expansion were studied. The obtained optimum condition for the foaming process was 9.62°Brix of PC, 8.18% of SMP, and 145.54 s of WT. The hot air drying of banana foam was carried out at 50–70°C; the drying rate and moisture diffusivity (3.9–5.9 × 10⁻¹⁰ m²/s) increased with drying temperature. The physico-chemical properties of banana foam powder such as moisture content, water activity, bulk density, and Carr index decreased with an increase in drying temperature, whereas hygroscopicity, water solubility index, and water absorption index increased. The dried samples were moderately bright in color and had a porous microstructure. The present study is expected to be useful in the preparation of banana powder.

Practical Applications

Foam-mat drying technology is a pragmatic method to dry fruit juices and pulps. The concept behind the foam-mat drying is an increase in the surface area of material to be dried. The process depends on the material property of pulp/juice and the use of the additives to create a foam structure and ensuring its stability during the phase of drying to offer granular products having low bulk density.