ATR-FT-MIR Based Inline Analysis for Determination of Phytate in Plant Residuals During Wet-Treatment

Abstract

Abstract The availability of organically bound phosphorus (P) as phytate in plant-based feeding material is a challenge for livestock farming due to limited utilization during the digestion by the animal. Another issue is the following output into the environment as manure, due to increasing restrictions for nitrogen and phosphorus. As a solution, enzymes such as phytases are added in livestock farming to increase digestibility. However, the activation of intrinsic enzymes by wet-treatment of feeding material can also effectively reduce phytate content and can be applied prior to feeding. In this study, we report on a non-invasive method based on Attenuated Total Reflection Fourier Mid-Infrared Spectroscopy (ATR-FT-MIR) and chemometrics for rapid quantification of residual phytate content during rye bran treatment; rye bran is used as an example for a plant-based feeding material. For model calibration, KH2PO4 was used as the internal standard, as phytate and its hydrolytic product ortho-phosphate experienced similar mid-infrared absorbance pattern. The residual phytate content after different treatment times was determined by applying a mass balance for P. The developed inline analysis is compared to standard offline analytical methods resulting in a RMSE of 6.2 mgphytate·100gbran-1. Thus, the developed method shows high accuracy and holds the potential for further applications for the screening and investigation of feed material conditioning prior to feeding.