Influence of modification method and starch concentration on the stability and physical properties of modified potato starch as wall materials

The object of this study was to investigate the stability of flavor encapsulated in modified starches, and the potentiality of modified starch as wall material. For the flavor encapsulation using freeze-drying technique, native potato starch (NP), β-cyclodextrin (β-CD), maltodextrin (MD) and acid-treated potato starch (ATPS), succinated potato starch (SPS) were used as wall materials and d-limonene was a core material. The properties of wall materials were evaluated by the physicochemical properties such as pasting property, microstructure, moisture absorption ratio and peroxide value of encapsulated d-limonene. The peak viscosity (RVU) of modified potato starch was lower values (299 and 375 RVU) compared to that (579 RVU) of NP. The microstructure of product with SPS showed homogeneous distribution of pore with a regular size in contrast to the irregular arrangement of pore of NP and ATPS, and the microcapsule stabilized by β-CD and MD had smaller pore size than modified starches. Overall the yield of encapsulated products was an increasing trend as the concentration of wall materials was increased from 5 to 10%, and the product with SPS had the highest value (93.35%). The moisture absorption ratio of products with β-CD and SPS did not affected by starch concentration. The peroxide value of encapsulated d-limonene during storage for 16 days had low values below 2.0 meq/kg of oil at all samples except for sample with ATPS. These results indicate that the encapsulated d-limonene with SPS by freeze drying showed the highest flavor retention and the oxidation stability of d-limonene.