Effects of ripening stage and steaming time on quality attributes of fat free banana snack obtained from drying process including fluidized bed puffing.

Healthy snacks have increasingly been interested in consumers. Puffing technique is an alternative to produce healthy snacks. Effects of ripening stage of banana and steaming time on quality of banana slices obtained from drying process including fluidized bed puffing were investigated. Bananas at the ripening stages 1 and 3 were steamed at 100 °C for 30 s up to 2 min and dried at 90 °C to moisture content of 25 % dry basis (d.b.). The samples were then puffed by fluidized bed dryer at 160 °C for 2 min and dried at the same temperature as the first stage drying. The experimental results showed that shrinkage, drying time, color, glycemic index and textural properties were affected by steaming time and ripening stage. Steaming provided more uniformity of banana color. Steaming positively or negatively affected the degree shrinkage of banana depending on the ripening stage. The banana texture in particular crispiness could be improved by the steaming for the ripening stage 1 banana whilst it did not improve for the ripening stage 3. During steaming, the C-type crystalline structure of banana starch disappeared and thus the value of glycemic index was increased. The ripening stage 1 banana was recommended for producing healthy snack in order to control glycemic response.