Microstructural and Rheological Properties of Camel and Bovine Milk Fermented with Five Lactic Acid Bacteria Strains

Area of Science:

• Food Science
• Microbiology
• Dairy Science

Background:

• Camel milk (CM) and bovine milk (BM) have distinct compositions influencing fermentation.
• Lactic acid bacteria (LAB) are crucial for fermented dairy products.

Purpose of the Study:

• To evaluate the fermentation performance of five LAB strains in CM versus BM.
• To compare bacterial viability, acidification, proteolysis, and rheological properties.

Main Methods:

• Fermentation of CM and BM with five LAB strains (Streptococcus thermophilus, Lactobacillus delbrueckii ssp. bulgaricus, Lb. helveticus, Lb. casei, Lactiplantibacillus plantarum) at 42°C for 48h.
• Analysis using fluorescence microscopy, acidification kinetics, OPA assay for proteolysis, scanning electron microscopy, and rheological measurements.
• Statistical analysis to determine significance (p < 0.001).

Main Results:

• Lower bacterial viability observed in fermented CM compared to BM.
• Significant differences in acidification kinetics and more pronounced proteolysis in fermented CM (OPA ~1.3-1.5 fold higher).
• Fermented CM exhibited more porous protein matrices, weaker gel networks, and lower rheological strength than fermented BM.

Conclusions:

• Fermentation performance of LAB is significantly influenced by milk type (CM vs. BM).
• Lb. casei showed superior adaptability, viability, acidification, and rheological properties in both milk types.
• Lb. casei is a promising candidate as a starter or adjunct culture for fermented dairy products using either CM or BM.