Effect of egg albumin concentration and carboxymethyl cellulose on properties of hom-thong banana [Musa acuminata (AAA group) 'Gros Michel'] foam snack produced by foam mat drying

The present work aimed to develop a dried hom-thong banana foam snack by incorporating egg albumin (EA) and carboxymethyl cellulose (CMC) for foam formation, followed by air drying, offering a technological alternative for the banana pulp. The effect of EA at different concentrations (5, 7.5, and 10%), incorporated without or with the addition of CMC (0 or 0.15%) into the mixture of banana foam (w/w), on its foam properties as well as the characteristics of the snacks, was investigated. An increase in the concentration of EA from 5% up to 7.5% resulted in an increase in foaming ability with foam expansion (400.50-535.19%), because entrapping air in the foam was limited at a maximum concentration of 7.5% EA. However, the addition of 0.15% CMC into the mixture of banana foam containing 10% EA (10% EA + 0.15% CMC) presented the highest foam expansion (641.62%), the lowest density (0.22 g/mL), and excellent foam stability estimated from without foam drainage. Moisture content and water activity (aw) of all banana foam snacks were low (5.08-7.84%) after air drying at 75 degrees C for 6 h, and the maximum aw value was less than 0.6 (0.18-0.25), ensuring the microbiological stability of the product at ambient temperature. When applying EA at a concentration of 5% and adding 0.15% CMC (5% EA + 0.15% CMC), the snack had high structure stability and was crispy, as its hardness and fracture force were 10.28 and 8.37 N, respectively, and a low colour negative appearance resulting from a lower browning index (BI) was found. This sample also received a high score for the sensory evaluation of appearance and overall acceptance. In comparison to the 10% EA sample, although the 5% EA + 0.15% CMC sample had lower trend for some sensory scores, its texture properties, colour, and BI values were superior. Therefore, to produce a dried banana foam snack using foam mat drying, applying EA at a concentration of 5% in addition of 0.15% CMC is recommended.