Oxidative stability of high-oleic sunflower oil in a porous starch carrier.

This study evaluates the oxidation level of high-oleic sunflower oil (HOSO) plated onto porous starch as an alternative to spray drying. Encapsulated oils were subjected to accelerated oxidation by heat and light exposure, and peroxide value (PV) and conjugated dienes (CD) were measured. Bulk oil was the control. PV increased in all samples with increased light exposure, with similar values being reached by oil carried on porous starch and spray dried oil. The encapsulation processes determined a reduced effect of light on the increase of CD in the oil, as compared to bulk oil. Spray dried oil presented the highest CD in the experimental domain considered. Since similar levels of PV and lower levels of CD were shown in the HOSO carried on porous starch compared to the spray dried HOSO, plating flavour oils on porous starch could be a suitable technological alternative to spray drying, for flavour encapsulation.

Evaluation of porous starch as a flavour carrier.

A commercial porous starch was evaluated for the use as a carrier for liquid flavours. Encapsulation trials performed with diacetyl showed a high initial load and good retention over time when more polar solvents commonly used in flavour creation were used. The physical interactions between the porous starch and solvents used in flavour creation were also studied. The glass transition temperature of the starch decreased upon addition of the polar solvents, ethanol and propylene glycol. Propylene glycol also produced an exothermic peak when mixed with porous starch, possibly due to the formation of complexes between the two components. Low resolution (1)H-NMR results suggested that a stronger interaction was established between more polar solvents and the porous starch, as indicated by a more marked decrease in relaxation times and proton diffusion coefficient of the solvents on adding porous starch.