Biofunctional attributes and storage study of milk fermented by Enterococcus italicus

Area of Science:

• Food Microbiology
• Probiotics and Prebiotics
• Food Science and Technology

Background:

• Lactic acid bacteria (LAB) are recognized for their probiotic properties and natural antioxidant capabilities, making them valuable in the food industry.
• The isolation and characterization of novel LAB strains with enhanced functional attributes are crucial for developing improved food products.

Purpose of the Study:

• To isolate and characterize a potent antioxidant strain of lactic acid bacteria from fresh milk.
• To evaluate the safety and functional properties of the isolated strain, Enterococcus italicus FM5.
• To assess the impact of co-culturing E. italicus FM5 with traditional yogurt starters on fermented milk quality.

Main Methods:

• Isolation and identification of Enterococcus italicus FM5 from fresh milk.
• Safety assessment including antibiotic sensitivity and hemolytic activity tests.
• Whole genome sequencing and bioinformatic analysis of E. italicus FM5.
• Co-cultivation experiments with Streptococcus thermophilus and Lactobacillus bulgaricus for fermented milk production.
• Evaluation of antioxidant activity (DPPH, ABTS, OH-, O2- radical scavenging), curd time, water holding capacity, and microbial growth.

Main Results:

• Enterococcus italicus FM5 demonstrated strong antioxidant activity and was confirmed safe (non-hemolytic, sensitive to common antibiotics).
• Co-culturing E. italicus FM5 with S. thermophilus and Lb. bulgaricus significantly enhanced the fermented milk's antioxidant capacity, with high scavenging rates for various radicals.
• The addition of E. italicus FM5 reduced curd formation time and improved the water holding capacity of the fermented milk.
• E. italicus FM5 significantly promoted the growth of Lb. bulgaricus, leading to increased viable cell counts in the fermented product.

Conclusions:

• Enterococcus italicus FM5 is a promising probiotic strain with significant antioxidant properties and beneficial effects on fermented milk production.
• Co-cultivation of E. italicus FM5 with traditional yogurt starters offers a viable strategy to enhance the nutritional and functional quality of fermented milk.
• This study highlights the potential of E. italicus FM5 for the development of novel, high-value fermented dairy products.