Fermentation endpoint detection of Soybean using specially designed Pd-coated FBG stress sensor

Determining the fermentation endpoint of organic compounds is critical for optimizing yield, ensuring the product consistency, and minimizing byproducts. However, conventional detection methods are slow, labor-intensive, and lack real-time monitoring, limiting their suitability for industrial automation. We propose a novel, non-destructive method for real-time detection of fermentation endpoint of Soybean using Palladium (Pd) -coated fiber Bragg grating (FBG) stress sensor. The fermentation endpoint can be detected by monitoring the shift in Bragg wavelength caused by the stress in Pd -coated FBG sensor due to the volume expansion of the Pd coating upon the formation of Palladium Hydride (PdHx) after Hydrogen (H2) gas absorption, which is released as a byproduct during Soybean fermentation. The Pd -coated FBG stress sensor is analytically designed and validated using OptiSystem simulation tool, achieving a high sensitivity of 61.6 p.m./MPa. Our findings confirm that this method provides a simple, efficient, and real-time solution for monitoring the fermentation process of organic compounds that produce H2 offering significant advantages over traditional techniques.