A study of the effect of the drying process on the composition and physicochemical properties of flours obtained from durian fruits of two ripening stages

<jats:title>Summary</jats:title><jats:p>Durian cv. <jats:styled-content style="fixed-case">M</jats:styled-content>onthong with two ripening stages (unripe and fully ripe) was subjected to microwave vacuum drying (<jats:styled-content style="fixed-case">MWD</jats:styled-content>) at 5.49 W g<jats:sup>−1</jats:sup> and hot air drying (<jats:styled-content style="fixed-case">HAD</jats:styled-content>) at 60 °C. With an increase in ripening degree, the starch content was significantly (<jats:italic>P</jats:italic> ≤ 0.05) decreased from 40.08–40.42% to 9.44–11.76%. <jats:styled-content style="fixed-case">X</jats:styled-content>‐ray diffraction indicated that the crystalline pattern was changed from starch to sucrose. The starch granule morphology of durian flour was conserved for both drying conditions. Peak gelatinisation temperatures of <jats:styled-content style="fixed-case">MWD</jats:styled-content> and <jats:styled-content style="fixed-case">HAD</jats:styled-content> flours were increased significantly (<jats:italic>P</jats:italic> ≤ 0.05) from 56.71–57.32 to 60.71–61.23 °C. Using different drying methods, <jats:styled-content style="fixed-case">MWD</jats:styled-content> flour had less a*‐value (<jats:italic>P</jats:italic> ≤ 0.05) than <jats:styled-content style="fixed-case">HAD</jats:styled-content> flour. The peak viscosity and trough of the <jats:styled-content style="fixed-case">HAD</jats:styled-content> unripe durian flour (5.92 <jats:styled-content style="fixed-case">RVU</jats:styled-content> and 3.45 <jats:styled-content style="fixed-case">RVU</jats:styled-content>, respectively) were significantly (<jats:italic>P</jats:italic> ≤ 0.05) lower than those of the <jats:styled-content style="fixed-case">MWD</jats:styled-content> unripe durian flour (34.32 <jats:styled-content style="fixed-case">RVU</jats:styled-content> and 11.57 <jats:styled-content style="fixed-case">RVU</jats:styled-content>, respectively).</jats:p>