Multi Response Optimization of Bioactive Starch Foam Composite Using Taguchi’s Method and Grey Relational Analysis

In this study, bioactive foam composite samples made from cassava starch and bioactive agents were prepared. The mix proportions of raw materials in the samples were designed using Taguchi method coupled with Grey relational analysis. L16 orthogonal array with three factors including spent coffee ground (SCG), zinc oxide (ZnO) and oregano essential oil/palm oil ratio (OEO/PO) at four-levels was chosen for determining an optimum mixture. Based on the signal-to-noise ratio and the analysis of variance of the results, additions of OEO/PO and SCG in the samples were the main factors in inhibition of Escherichia coli and Staphylococcus aureus . Furthermore, it was found that the increase of SCG, ZnO and PO in ratio of OEO/PO in the samples resulted in enhancement of flexural strength of bioactive foam composites. It appears that ZnO and OEO/PO were the major factors to improve water resistance of the samples. Also, the best ideal mixed proportion of the bioactive foam composite samples was obtained from Grey relational analysis.