Quality of Raw Materials in Food Processing

**75**

**Chapter 5**

**Abstract**

**1. Introduction**

Microbiological Quality of

Leaves (*Olea europaea L.*)

*Cristiane Marangoni, Alexandre José Cichoski* 

*and Juliano Smanioto Barin*

*Clostridium perfringens,* and *Escherichia coli*.

Chicken Meat Fed with Olive

This study evaluated the antimicrobial activity of olive leaves in vitro and meat chicken fed with percentages of 5 and 10 g of olive leaves for each kg feed. This is justified by the relevance of obtained safe products, with emphasis on the use of natural additives. The olive leaves presented antibacterial activity in all tested bacteria. For the bacteria *Yersinia enterocolitica*, *Escherichia coli*, and *Shigella*, the minimal inhibitory concentration varied from 0.6 to 1.5 mg/ml. The treatment with an addition of olive leaves showed better microbiological stability of the thighs and drumsticks of chickens than treatment without an addition of olive leaves. The use of 5 g/kg diet inhibited the growth of *Staphylococcus aureus* and *aerobic psychrotrophic* and aerobic mesophilic, while the use of 10 g/kg of diet inhibited the growth of *Enterococcus* spp., lactic bacteria, thermotolerant coliforms, *Pseudomonas*,

**Keywords:** antimicrobial activity, olive leaves, natural additive, chicken meat

viruses, and fungi, maintaining the quality of meat for a long time.

against Gram-positive and Gram-negative bacteria.

In order to inhibit microbial growth of raw materials or cuts, it is often more effective than the direct addition of preservatives to add compounds into the diet of the growing animals [1]. The phenolic compounds occurring naturally in the plants have the ability to inhibit the growth of microorganisms, including bacteria,

In a study conducted by Bisignano et al. [2], the in vitro antimicrobial activity of oleuropein and hydroxytyrosol extracted from olive leaves was evaluated, and the efficiency for the pathogenic bacterium *Staphylococcus aureus* was identified. In another study Bisignano et al. [3] identified the antimicrobial components of olive leaves, and they discovered the effectiveness of long-chain aliphatic aldehydes

In a study conducted by ERBAY and ICIER [4], the main compound found in olive leaves was oleuropein, being 24.54% in dry leaves. In a study realized by Paiva-Martins [5] with an objective of to assess the influence of OL supplementation at a lower level on feed digestibility and meat quality, the results indicated that olive leaves may be included in pig diets at 25 g/kg in order to improve the tocopherol content of meat without excessively compromising growth performance.

## **Chapter 5**
