Microwave vacuum-dried durian flour and its application in biscuits

Durian is one of most popular fruits due to its nutritional values and unique flavor. Durian products have been continuously developed to meet market needs. In this study, durian (Durio zibethinus Murr.) cv. 'Monthong' was subjected to microwave vacuum-drying at 1,200 W to produce durian flour for use in biscuits that are normally made from wheat flour. The microwave treatment induced starch gelatinization to a significant extent. As a result, compared to the wheat flour, the durian flour had lower viscosity, pasting temperature, gelatinization temperatures, and enthalpy of gelatinization but higher water absorption capacity. Dough properties including development time, dough stability, time to breakdown and the phase angle tangent of the durian dough were less than those of the wheat dough. The elastic modulus (G') and viscous modulus (G″) of the durian dough were higher than for the wheat dough. All the tested durian doughs had higher G' values than G″, indicating a viscoelastic structure. Substitution of wheat flour with durian flour should not exceed 50% to obtain reasonable dough properties and baking quality of durian biscuits.