Encapsulation and characterisation of grape seed proanthocyanidin extract using sodium alginate and different cellulose derivatives

Summary Grape seed proanthocyanidin extract (GSPE) has health benefits. However, these phenolic compounds undergo degradation reactions and have undesirable sensorial characteristics. GSPE was encapsulated using sodium alginate (SA), SA‐methyl cellulose (MC) and SA‐hydroxypropyl methylcellulose (HPMC) for promoting controlled release, pH stability, temperature and storage period tolerance of GSPE. The microcapsules were characterised using scanning electron microscopy (SEM) and Fourier transform infra‐red (FTIR) analysis. The SA‐MC and SA‐HPMC microcapsules appeared to have a more compact surface than SA‐alone microcapsules. FTIR analysis indicated successful immobilisation of GSPE into the polymeric microcapsules. Moreover, the SA‐MC and SA‐HPMC microcapsules showed higher thermal stability. The microcapsules showed a relatively higher amount of released GSPE at a pH above six than at a lower pH. The SA‐MC and SA‐HPMC microcapsules could be used to retain more GSPE content in the gastric phase and to release it in the intestinal phase for possible absorption. Furthermore, after 28 days of storage at 25 °C, the GSPE retention rate of the microcapsules was still higher than 80%. GSPE encapsulated in SA‐MC and SA‐HPMC microcapsules results in lesser degradation and can be absorbed more effectively. This method has potential for the delivery of colon‐specific materials while exhibiting a sustained‐release characteristic.