Development and validation of a spectroscopic method to predict wheat protein digestibility

Area of Science:

• Animal Nutrition
• Analytical Chemistry
• Spectroscopy

Background:

• Traditional crude protein (CP) digestibility measurement relies on chemical analysis.
• Spectroscopy offers a rapid, non-destructive alternative for chemical information.
• Predicting CP digestibility using spectral data is a potential advancement.

Purpose of the Study:

• To develop and validate a spectroscopic method for predicting in vivo CP digestibility.
• To assess the accuracy of Fourier transform mid-infrared (FTIR) spectroscopy for CP digestibility prediction.
• To correlate spectral data with measured apparent ileal digestibility (AID) of CP.

Main Methods:

• Developed a spectroscopic method based on Beer's law.
• Scanned digesta and diet samples of wheat grain using FTIR spectroscopy.
• Calculated AID of CP from spectral peak intensities and marker concentrations.
• Compared predicted AID of CP with in vivo measurements.

Main Results:

• The FTIR method accurately predicted AID of CP in wheat-based diets with a deviation of 0.68 ± 0.86%.
• Predicted AID of CP ranged from 60.4% to 87.8%.
• Functional group digestibility, particularly the Amide I region (1,643 cm(-1)), strongly correlated with in vivo AID of CP (r ≥ 0.99).

Conclusions:

• CP digestibility can be accurately predicted directly from FTIR spectra.
• Spectroscopic analysis offers a faster and non-destructive alternative to traditional chemical analyses.
• This method holds potential for routine application in animal nutrition and feed analysis.