Structural characterization and functional properties of CNPP, a byproduct formed during CPP preparation.

Area of Science:

• Biochemistry
• Food Science
• Nutritional Science

Background:

• Casein nonphosphopeptide (CNPP) is a large-scale byproduct of casein phosphopeptide (CPP) production.
• Previous research indicated CNPP's potential benefits for muscle wasting disorders, but its mechanism remains unclear.

Purpose of the Study:

• To elucidate the structure-function mechanism of CNPP by characterizing its physicochemical and functional properties.
• To provide a basis for CNPP's application as a functional ingredient against sarcopenia.

Main Methods:

• Structural characterization of CNPP (molecular weight, amino acid composition, sulfhydryl content).
• Fourier transform infrared spectroscopy (FTIR) for protein unfolding analysis.
• Fluorescence spectroscopy for structural changes.
• Evaluation of functional properties (solubility, foaming, emulsification, digestion).

Main Results:

• CNPP is low molecular weight, rich in leucine, with reduced sulfhydryl content compared to casein.
• Enzymatic hydrolysis induced protein unfolding in CNPP, increasing beta-turns and random coils.
• CNPP exhibited superior solubility, foaming, and digestion properties compared to casein and whey protein.
• Foam stability and emulsification decreased in the order: casein > CNPP > whey protein.

Conclusions:

• Structural characteristics of CNPP significantly influence its functional properties.
• CNPP possesses favorable physicochemical and functional attributes for potential use as a functional ingredient.
• This study provides foundational data for leveraging CNPP in sarcopenia management.