Dietary Supplementation of Tannin-Extracts to Lambs: Effects on Meat Fatty Acids Composition and Stability and on Microbial Characteristics.

Biondi Biondi,Caggia Caggia,Hoorde Hoorde,Russo Russo,Pino Pino,Randazzo Randazzo,Natalello Natalello

doi:10.3390/foods8100469

Abstract

Two extracts derived from plant material rich in hydrolysable (Tara, T; Caesalpinia spinosa) or condensed (Mimosa, M; Acacia mearnsii) tannins were added to lamb’s diet and their effects on meat quality and on microbial population were evaluated; a diet without tannins represented the Control (C). Meat pH, vitamin E, intramuscular fat content and muscle fatty acid composition were determined. Oxidative stability and microbiological analyses were performed on meat samples after 0, 4 and 7 days of refrigerated storage. Psychrotrophic bacteria were identified through MALDI-TOF MS analysis. Regarding meat fatty acids, Tara treatment decreased the percentage of monounsaturated fatty acids. The counts of all microbial groups were similar among dietary treatments at day 0, while a significant reduction of microbial loads was observed in T-group at day 7. Pseudomonas fluorescens group count was significantly affected by T extract supplementation. The MALDI-TOF MS identification revealed the dominance of Pseudomonas fragi species in all samples while Pseudomonas lundensis, Brochothrix thermosphacta and Candida famata were revealed only in control ones. In conclusions, the tannin extract supplementation is a promising dietary strategy to preserve lamb meat quality.

Highlights

In the last decade, the demand for natural preservative agents has increased due to the growing concern, among consumers, about the potential toxic effect of the synthetic antioxidants [1]
A number of reviews deal with the addition to feed or meat and meat products of plant extracts as natural antioxidants and antimicrobial agents [1,2,3]
Intramuscular fat content and muscle pH were not affected by the addition of Tara or Mimosa tannin extract to the basal diet (Table 2)

Summary

Introduction

The demand for natural preservative agents has increased due to the growing concern, among consumers, about the potential toxic effect of the synthetic antioxidants [1]. A number of reviews deal with the addition to feed or meat and meat products of plant extracts as natural antioxidants and antimicrobial agents [1,2,3]. Animal responses to dietary tannins have been extensively reviewed mainly focusing on animal nutrition and production [5,6]. Tannins could be exploited to favorably modulate FA composition of ruminant products [4,9]. Controversial results on the effect of tannins on the meat FA composition have been observed in vivo [10,11]. Such inconsistency could be due to the type of tannin

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Conclusion