Of critical concern is a fundamental methodological flaw in your synergy analysis that compromises the core premise of your study. Your calculation of the synergistic Index (SI) in Equation (3) requires the biodiesel yields from the individual, pure oils (WVO, NSO, CSO) to serve as the baseline for comparison. However, your paper provides no experimental data for the biodiesel yield of any of these individual feedstocks under the transesterification conditions used for the blends.
How can you conclusively state that “SI values were greater than 1” and claim a “positive synergistic effect” without the essential control data from the pure oils? The entire statistical validation via bootstrap resampling is built upon these undefined SI values, rendering your central claim of synergy scientifically unsubstantiated. Without this evidence, on what basis can you assert that blending is beneficial, and does this not fundamentally undermine the justification for your optimally formulated ternary blend and the subsequent interpretations drawn from your SHAP analysis?