Biochemical and Functional Properties of a Novel Curd-Based Products on Traditional Mongolian Fermentation Method

This study aims to investigate the biochemical and functional properties of innovative curd-based products prepared by the traditional method. In this study, four samples (raw curd, curd powder, curd balls, and curd drink) were analyzed using Kjeldahl method for protein, Soxhlet for fat, atomic absorption spectrophotometry for minerals, RP-HPLC for amino acids and organic acids, SDS-PAGE and HPLC for protein fractions, DPPH assay for antioxidant activity, antibacterial assays, and laser diffraction for particle size distribution. The raw curd contained 13.96 ± 0.15 g protein, 6.77 ± 0.19 g fat, and 0.42 ± 0.05 g calcium, corresponding to 30.08 mg Ca per gram of protein. Lactic acid was the major organic acid, with concentrations ranging from 16.04 to 32.00 mg/g in curd balls and powder, respectively. The highest antioxidant activity was observed in raw material (72.3 ± 1.50% DPPH inhibition) followed by curd balls (53 ± 2.00%). Particle size analysis revealed a monomodal distribution with a median diameter (D50) of 3.7 ± 0.20 µm. Antibacterial activity was observed in non-neutralized samples, indicating pH-dependent inhibitory effects. These findings support the potential of traditionally fermented curd as a functional dairy product that preserves bioactive peptides and antioxidant properties while adapting to modern consumer demands.