Evaluation of different foaming agents for foam mat drying of tamarind pulp: A comparative study of maltodextrin, egg white and whey protein

The present investigation entitled “Evaluation of Different Foaming Agents for Foam Mat Drying of Tamarind Pulp: A Comparative Study of Maltodextrin, Egg White and Whey Protein” was undertaken at Department of Agricultural Process Engineering, Dr. Annasaheb Shinde College of Agricultural Engineering and Technology, M.P.K.V., Rahuri during the year 2023-2025. This research presents a comprehensive comparative evaluation of three foaming agents, maltodextrin, egg white, and whey protein, for the foam mat drying (FMD) of tamarind pulp, a tropical fruit with significant nutritional and economic importance but challenged by high moisture content and perishability. The study systematically assessed the impact of each foaming agent combined with hydroxypropyl methylcellulose (HPMC) stabilizer on critical drying performance parameters, including foam expansion, foam density and powder recovery. Results demonstrated that maltodextrin-HPMC exhibited superior performance with the highest foam expansion of 84.3%, the lowest foam density of 0.69 g/cm³ and the greatest powder recovery of 41.5%, significantly outperforming the protein-based alternatives. This superiority is attributed to maltodextrin’s dual role as both a foaming and carrier agent, its excellent stability under the acidic conditions (pH 2.8-3.2) of tamarind pulp, and its effective surface activity facilitating enhanced air incorporation and drying efficiency. The addition of HPMC stabilizer significantly enhanced powder yield, evidencing a strong synergistic effect. The study’s findings underscore maltodextrin-HPMC as a highly effective and commercially viable system for producing high-quality tamarind pulp powder through foam mat drying, offering reduced drying time, improved energy efficiency, and extended shelf life while preserving the nutritional and sensory qualities of tamarind. This work establishes a clear scientific foundation for industrial adoption and future optimization of FMD technology for tamarind and similarly challenging acidic fruit matrices, thereby contributing to minimizing post-harvest losses and promoting value addition in tropical fruit processing.