Effect of different drying methods on the nutritional and physicochemical properties of unpeeled banana flour

Abstract

This work was conducted to evaluate the effect of drying methods on the nutritional values and physicochemical properties of unpeeled banana flour. Proximate, amylose content, phenolic compound, resistant starch, total dietary fibre, functional properties, pasting properties, and thermal properties of dried banana flour samples were evaluated. Three different drying methods of whole banana with the intact peel were studied including 1) hot-air unpeeled flour (HAU) (dried at 60oC for 2 h in hot-air chamber), 2) microwave-vacuum unpeeled flour (MVU) (36,000 W under vacuum -600 mmHg for 15 min in a pilot microwave-vacuum dryer), and 3) infrared unpeeled flour (IRU) (600 W for 15 min in infrared channel dryer). The HAU and MVU showed the highest yield. Drying methods did not affect the compositions of the flour but significantly affected the total dietary fibre, resistant starch, amylose content and phenolic compound of the flour. Among samples, HAU contained the highest nutritional values with outstanding functional properties, and pasting properties. The unpeeled banana flour can be utilized in various food products such as noodle, bakeries, snack or used as functional ingredients for nutritional purposes.