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

## TL;DR

This study compares how five lactic acid bacteria ferment camel and bovine milk, finding differences in bacterial viability, acidification, and texture.

## Contribution

The study provides new insights into the fermentation behavior of lactic acid bacteria in camel milk compared to bovine milk.

## Key findings

- Fermented camel milk showed lower bacterial viability and more proteolysis than bovine milk.
- Camel milk had weaker gel networks and lower rheological strength compared to bovine milk.
- Lb. casei showed better adaptability and favorable properties in both types of milk.

## Abstract

This study assessed the fermentation performance of five lactic acid bacteria (Streptococcus thermophilus, Lactobacillus delbrueckii ssp. bulgaricus, Lb. helveticus, Lb. casei, and Lactiplantibacillus plantarum) in camel milk (CM) and bovine milk (BM) at 42 °C for 48 h. Fluorescence microscopy revealed lower bacterial viability in fermented CM compared to BM. Acidification kinetics varied significantly between CM and BM, and proteolysis was more pronounced in fermented CM (p < 0.001), with OPA concentrations ~1.3–1.5-fold greater in CM across all strains during fermentation. Scanning electron microscopy revealed more porous, loose protein matrices in fermented CM than in BM, in line with the rheological analyses showing weaker gel networks and lower rheological strength in fermented CM. Lb. casei demonstrated superior adaptability, enhanced viability, balanced acidification, and favorable rheological properties in both milks, highlighting its potential as a possible starter or adjunct culture in fermented dairy products.