# Tannin Rich-Extracts: Natural Solutions for Preserving the Physicochemical, Oxidative, and Microbiological Quality of Beef Patties During Cold Storage

## TL;DR

Tannin-rich extracts can naturally preserve beef patties by reducing oxidation and improving quality during cold storage.

## Contribution

Tannin-rich extracts are shown to be more effective natural antioxidants than rosemary extract in beef patties.

## Key findings

- Tannin-rich extracts significantly reduced lipid oxidation and MDA formation in beef patties.
- Tannin-rich extracts outperformed rosemary extract in antioxidant efficacy (p < 0.001).
- Natural extracts improved meat redness without affecting texture or microbial growth.

## Abstract

Increasing consumer demand for healthier and clean-label meat products, together with health concerns over synthetic antioxidants, has driven interest in natural alternatives. In this context, tannin-rich extracts were evaluated as functional ingredients to improve the quality and shelf life of beef patties. The effect of two different tannin-rich extracts, each tested at three different concentrations (0.005%, 0.02%, and 0.04% w/w), was investigated in beef patties. Obtained results were compared with a commercial rosemary extract (0.2% w/w) and an untreated control. Natural antioxidant supplementation significantly reduced lipid oxidation during refrigerated storage, limiting malondialdehyde (MDA) formation. At the end of the 7-day storage period, the control sample exhibited the highest thiobarbituric acid reactive substance (TBARS) value of 2.99 ± 0.01 mg MDA/kg, whereas treated samples showed markedly reduced oxidation (0.34–0.97 mg MDA/kg), with tannin-rich extracts presenting greater antioxidant efficacy with respect to rosemary extract (p < 0.001). The natural compounds also effectively inhibited hexanal formation and delayed the accumulation of 1-octen-3-ol compared with the control (p < 0.001). Moreover, all extracts enhanced meat redness, as indicated by higher CIELAB a* values, while no significant effects (p > 0.05) were observed on texture, microbial growth, or overall sensory acceptance. These results highlight tannin-rich extracts as promising natural antioxidants for improving oxidative stability and extending the shelf life of beef patties.