Emerging Technologies in Agriculture and Food Science

Karim Ennouri

• Publisher: Bentham Science Publishers
• Year: 2020
• Print ISBN: 9789811469985
• eBook ISBN: 9789811470004
• Topic: Technology & Engineering
• Subtopic: Agriculture
• Index: Technology & Engineering

Cultivators and livestock farmers are increasingly arranging innovative technical andscientific estimations with the aim to enhance agricultural sustainability, effectiveness, and plant health. Innovative farming technologies incorporatebiology with smart technology (computers and sensor devices) exchanginginformation with one another autonomously in a structured farm managementsystem. This book presents reviews on innovative techniques and methodologiesto complement conventional plant control and breeding attempts toward enhancingcrop yield and production. Reviews covered in this volume include: -Active compounds from pomegranate seeds-Application of Enterococci andtheir bacteriocins for meat biopreservation-Technological advancement in the detection and identification of plantpathogens-Machine learning for precision agriculture-Use of remote sensing technology and geographic information systemsfor agriculture andenvironmental observationThe information presented in this volume will provide helpful updatesfor students, technology experts and professionals in the food security andsustainable agriculture sectors.

Application of Enterococci and their Bacteriocins for Meat Biopreservation

Olfa Ben Braïek^{1, *}, Paola Cremonesi², Stefano Morandi³

¹Laboratory of Transmissible Diseases and Biologically Active Substances (LR99ES27), Faculty of Pharmacy, University of Monastir, Tunisia

² Institute of Agricultural Biology and Biotechnology, Italian National Research Council (CNR IBBA), Lodi, Italy

³ Institute of Sciences of Food Production, Italian National Research Council (CNR ISPA), Milan, Italy

Abstract

Nowadays, consumers are more aware and conscious about health concerns related to foods, which increase their demand for more safe food, particularly meats, free of additives such as preservatives, and if so with natural ones. In line with this, bacteriocinogenic lactic acid bacteria (LAB) and their bacteriocins have been widely screened and studied in the last years in view of their use in meat biopreservation. This chapter presents an emphasised overview regarding enterococci and their produced bacteriocins (enterocins) as part of interesting LAB and biomolecules with promising potentialities to be used in meat preservation as alternatives to synthetic preservatives thus satisfying consumers’ demand for healthy and “bio” meat. Indeed, the characteristics of enterococci and enterococcal bacteriocins were described based on published literature. Further, we have reviewed some of the research on their applications for biopreservation of meat and meat products with a focused discussion on diverse topics such as their advantages as well as the challenges and limits of their use in meat. Finally, the synergistic approaches based on combinations of enterococcal protective cultures and/or enterococcal bacteriocins with other technological concepts to improve safety and quality of meats are reported and discussed.

Keywords: Application, Bacteriocin, Biopreservation, Biopreservative, Enterococci, Enterococcus, Enterocin, Lactic acid bacteria, Listeria monocytogenes, Meat, Pathogen, Protective culture, Spoilage.

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^* Corresponding author Ben Braïek Olfa: Laboratory of Transmissible Diseases and Biologically Active Substances (LR99ES27), Faculty of Pharmacy, University of Monastir, Tunisia; E-mail: [email protected]

INTRODUCTION

Microorganisms represent a risk to human health from food-borne illnesses and a problem to economic losses. Considering this, chemical additives are intensively

used to inhibit microbial proliferation and extend the food shelf-life [1].

As a result, several studies demonstrated that synthetic food preservatives have been linked to toxicological problems and diseases (allergic reactions, heart diseases, neurological problems and cancers) [2]. Besides, consumers are increasingly demanding safe and “bio” foods without chemical preservatives which encourage food industries to search and apply for novel strategies based on ensuring food safety and extending their shelf-life with natural antimicrobials that fall in the principle of “food biopreservation”.

Several bacteria could produce antimicrobial substances called “bacteriocins”, but those produced by lactic acid bacteria (LAB) have gained a great interest in recent researches [2, 3]. Among these LAB, enterococci and their produced bacteriocins called “enterocins” have received considerable attention and were extensively studied for their potentialities to be used in food biopreservation thanks to their large spectrum of antimicrobial activities against many food-borne pathogens and spoilage bacteria such as Listeria monocytogenes, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Bacillus spp [4].

For this purpose, the application of enterococci in foods could be realised according to two methods; (i) direct application of the bacteriocin-producing strain into food matrix as bioprotective culture or (ii) direct application of cell-free supernatant (CFS), partially purified or purified bacteriocin as a food preservative [5, 6]. These techno-biological strategies need in-depth studies regarding the safety aspects of the inoculated antimicrobials supported by toxicological data, their activity and efficacy in foods and their bactericoin production process prior to their legal approval by the authorities as applicable preservative agents. On the other hand, the incorporation of enterococci or their enterocins in packaging could be another technique to ensure microbiological quality and safety of foods [5, 6].

Among the foods that were much studied in the last years to be inoculated with enterococci and/or their enterocins to improve their overall safety, we could notice meats which represent an important source of valuable nutrients in the human diet [6, 7]. However, they are characterised by a very short shelf-life due to their composition ideal to various microbial proliferation and contamination leading to a health risk for consumers, a degradation of organoleptic quality (appearance, texture, odour, flavour, and colour) and an economic loss in meat industries.

This chapter will cover general features on enterococci and their bacteriocins as natural “solutions” attempting to solve these issues. Nevertheless, researchers and industries will always face conflicting challenges to assure meat safety and meet consumers’ satisfaction. Furthermore, earlier works [8, 9] generally illustrated the role of enterococci and/or enterocins in diverse foods; however, a fewer [10] emphasised their functionalities in meat and meat products. With this aim, the present chapter summarises the most relevant insights obtained during the last years about the practical importance of enterococci and enterocins for use in biopreservation of meat as food example and highlights in detail their current applications in the meat industry by discussing both advantages and limitations and finally exposes some approaches with high hope to mainly overcome these limitations.

General Characteristics of Enterococci

Enterococci are Gram-positive, catalase and oxidase-negative, facultative anaerobic and non-spore-forming bacteria [11]. Until now, this LAB genus contains about 37 identified species, but E. faecium and E. faecalis remain the most abundant among them [12].

Enterococcus species can grow at a temperature range from 10°C to 45°C in aerobic conditions [13]. They can also grow in a wide range of pH (4.4-9.6) and tolerate media with 6.5% of NaCl and the presence of 40% (w/v) of bile salts [14].

Enterococci usually inhabit the alimentary tract of humans and animals, and can be present in various ...

Table of contents

• Welcome
• Table of Content
• Title
• BENTHAM SCIENCE PUBLISHERS LTD.
• FOREWORD
• PREFACE
• LIST OF CONTRIBUTORS
• Active Compounds from Pomegranate Seed: New Source for Food Applications
• Application of Enterococci and their Bacteriocins for Meat Biopreservation
• Technological Advancement in the Detection and Identification of Plant Pathogens
• Machine Learning for Precision Agriculture: Methods and Applications
• Use of Remote Sensing Technology and Geographic Information System for Agriculture and Environmental Observation