Predictive Model for Shea Stearin Applicability Using Refractive Index

Organization: Bunge Limited
Date: Dec 2019 – Nov 2020

Project Abstract

This project aimed to replace expensive and time-consuming wet-chemistry analysis with a rapid, chemical-free proxy method for screening shea stearin quality. By establishing a correlation between Refractive Index (RI) and key quality parameters, we developed a tool to accelerate decision-making in production environments.

Technical Methodology

The core of the solution involved building and validating a pair of linear regression models to predict Iodine Value (IV) and StOSt triglyceride content directly from Refractive Index (RI) measurements.

  • Data Collection & Processing: Curated a dataset of historical quality parameters and corresponding RI measurements. Implemented a robust outlier-handling strategy (e.g., Z-score, IQR) to clean the training data.
  • Model Development: Developed simple linear regression models (OLS) determining the coefficient and intercept for the prediction equation:
    Y = β₀ + β₁X + ε
  • Feature Assessment: validatated the assumption of linearity and homoscedasticity of residuals to ensure model reliability.

Model Performance & Validation

The models demonstrated strong predictive power, sufficient for rapid screening purposes:

Iodine Value (IV) Model

  • R²: 0.779
  • RMSE: 0.640

StOSt Content Model

  • R²: 0.779
  • RMSE: 0.642

Operational Impact

  • Cost Reduction: Eliminated the need for solvents and chemical reagents for routine screening, significantly lowering analytical costs.
  • Efficiency: Reduced turnaround time from hours (GC/titration) to minutes (RI measurement), enabling faster feedback loops for process control.
  • Sustainability: Validated RI as a "green" analytical proxy, supporting laboratory waste reduction goals.