Phenolic Compounds and Derivatives in Ruminant Meat and Milk: A Systematic Review.

Area of Science:

• Food Science
• Animal Science
• Nutritional Science

Background:

• Phenolic compounds are bioactive molecules found in plants, with potential health benefits.
• Ruminant products (meat and milk) can accumulate phenolics from animal diets.
• Understanding phenolic profiles in ruminant-derived foods is crucial for human nutrition.

Purpose of the Study:

• To synthesize existing evidence on phenolic concentrations and diversity in ruminant meat and milk.
• To investigate factors influencing phenolic content, including animal species, management, forage type, and seasonality.
• To explore the role of ruminants in mediating phenolic transfer from plants to human diets.

Main Methods:

• Systematic review of 39 studies.
• Analysis of phenolic concentrations and diversity using total phenolic content assays and targeted mass spectrometry.
• Consideration of various influencing factors: animal species, management systems, forage types, and seasonality.

Main Results:

• 356 distinct phenolics identified in ruminant meat and milk.
• Goat milk exhibited the highest phenolic concentrations (1390 μg GAE/mL by TPC assay; 26.79 μg/mL by MS).
• Beef displayed the greatest phenolic diversity (164 metabolites), followed by sheep milk (110 metabolites).
• Organic/agroecological systems, fresh forages, and younger pastures were linked to higher phenolic content.
• Red clover promoted higher phenolic diversity than chicory, lucerne, or white clover.
• Maize silage resulted in higher phenolic content than ryegrass silage.

Conclusions:

• Ruminants act as biological mediators, transferring plant phenolics into meat and milk.
• This process 'upcycles' phenolics from plants not typically consumed by humans.
• Further research integrating soil, plant, animal, and food sciences is needed to understand the full significance for human health.