6533b7defe1ef96bd127685a

RESEARCH PRODUCT

Water and temperature contribution to the structuration of starch matrices in the presence of flavour.

subject

description

The effect of hydrothermal treatments and flavours addition on starch structure and its physical properties were studied. Native wheat starch was treated at 2 different hydrations (water-starch ratios: 50/50 and 80/20 g w/w) and temperatures (65 and 85 °C) in the presence of flavours (ethyl hexanoate and 2-hexanone). The freshly prepared samples were subjected to DSC and flavour analysis. Flavour inclusion complex could not be detected by DSC, however the result of flavour analysis proved that there were flavours interactions with starch. Both ethyl hexanoate and 2-hexanone interacted with starch at similar rates. The highest flavour loss was found in the samples at high hydration and heated at 85 °C. The loss of flavour was mainly due to vaporisation during hydrothermal treatments. After hydrothermal treatments, the samples subjected to freeze-drying and they showed flavour stability upon freeze-drying. The freeze-dried samples were subjected to various studies: DSC (Tg), RVA, granule size, XRD, WAXS, SAXS and storage study. The hydrothermal treatments resulted in samples with different properties. At high hydration, temperature influenced granule size and pasting properties. The samples heated at 65 °C had significantly greater granule diameter, lower peak viscosity than samples heated at 85 °C and no significantly difference in % crystallinity. At low hydration, heating temperature had no significantly influence on granule diameter but significantly affected pasting properties, % crystallinity and SAXS profile. The samples heated at 65 °C had a greater peak viscosity, % crystallinity and greater peak on SAXS than after a treatment at 85 °C. The residual flavour contenthad no significant influence on structure but affected pasting properties. Regarding storage study, the samples were stored at 58 and 75 % RH and withdrawn for SPME, flavour residual extraction and DSC (enthalpy of relaxation) at 2, 4 and 14 weeks of storage. The samples had greater flavour release at 75% RH and ethyl hexanoate showed greater release than 2-hexanone. The samples showed increasing of enthalpy relaxation upon storage.