Preface

The identification of solutions to improve the life and health of consumers, providing safe food of high quality, is the major concern in Food Science. Towards that goal, preservation methods such as salting, drying, high/low temperature application, fermentation, and more recently, pulsed electric field, high pressure and radiation alone or combined – may be applied. The choice of the preservation process will depend on the food type, availability of the method, cost effectiveness and the degree of change it causes to the flavor and nutritional features of the food product. However, few preservation methods present the advantages of fermentation or biopreservation using lactic acid bacteria (LAB), which is cheap, widely accessible and meets today's increasing consumer's demand for minimally processed/preserved food products. Biopreservation is indeed one of the oldest forms of food preservation technologies and a proved highly efficient non-thermal processing method.

 The rapidly changing consumption patterns of the global market and the desire for minimally processed foods is pushing the industry to find processing methods that meet the consumers desire and also increase products safety. LAB fermentation is common in production of dairy, meat, vegetable and fish products, as well as, animal feed. It is based on LAB ability to ferment sugars, especially glucose and galactose, leading to formation of lactic acid, and other metabolites that bring desirable texture and flavors changes to fermented foods, besides increasing their safety via release of bacteriocins. Considerable research is focused on these ribossomaly sintethesized proteins, because of their potential optimized applications in food, pharmaceuticals, nutraceuticals, and veterinary and human medicine. Their presence in foods is in general considered safe for consumers because they are inactivated by pancreatic or gastric enzyme.

New research in the fields of genomics, proteomics and genetic engineering is helping us understand better LAB physiology, pushing further the boundaries of their potential applications. In fact the isolation and characterization of new LAB strains, is one of the most active fields of research in Food Science today.

Many LAB have been identified as suitable for probiotic foods production - defined as a preparations containing viable defined microorganisms in sufficient numbers, which positively alter the GI tract microbiota. In fact LAB probiotic cultures have been

proposed as alternative to antibiotic therapy in patients affected *Clostridium difficile.*  LAB are applied in production of prebiotics, which are polyssacharides ingredients that encourage the growth and activity of beneficial bacteria in the GI tract, as well as in the manufacture of enzymes and other pharmaceutical products - namely as potential vehicles for production of new vaccines and new antibiotics.

The compilation and discussion of these many fields of application of LAB is the core of this book. We thank all contributors from around the world that have lay down here their outstanding scientific research and make it available to the vast public of readers - researcher, academics, corporate R & D, students or just curious person interested in the subject. Either way, I hope you enjoy reading it and find the contents of the book useful.

I would like to thank my wife, Karyne for her support of my academic endeavors, which, from time to time have meant, unfortunately, enjoying a little less of our family time.

> **J. Marcelino Kongo** Instituto de Inovação Tecnológica dos Açores (INOVA) Canadian Research Institute of Food Safety)

**Dairy Food Products** 

**Chapter 1** 

© 2013 Kongo, licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

© 2013 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution,

distribution, and reproduction in any medium, provided the original work is properly cited.

and reproduction in any medium, provided the original work is properly cited.

Milk is a highly perishable food raw material, therefore, its transformation in cheese or other form of fermented dairy product, provides an ideal vehicle to preserve its valuable nutrients (Table 1), making them available throughout the year. It is known that while unprocessed milk can be stored for only a few hours at room temperatures, cheeses may reach a shelf-live

**Lactic Acid Bacteria as Starter-Cultures** 

**Past, Present and Future Developments** 

The identification of solutions to improve the life and health of consumers, providing safe and nutritious foods, is the major concern in Food Science. Toward that goal, preservation methods such as salting, drying, high/low temperature application, fermentation, and more recently, pulsed electric field, high pressure and radiation - alone or in combination – may be applied. The chosen method will depend on the type of raw materials, availability of the method, cost, effectiveness and degree of change it causes to the flavor and nutritional features of the food product. Fermentation, also called biopreservation, is a cheap, widely accessible method that meets today's increasing consumer´s demand for minimally processed/preserved food products. Biopreservation with lactic acid bacteria (LAB) is indeed one of the oldest and highly efficient forms of non-thermal processing method. Cheese production is based on LAB ability to ferment sugars, especially glucose and galactose, so to produce lactic acid and aroma substances that give typical flavors and tastes to fermented products. LAB also release antimicrobial metabolites so called bacteriocins, which are considered safe and natural preservatives, with great potential to be used on their

**for Cheese Processing:** 

Additional information is available at the end of the chapter

own, or synergistically with other methods in food preservation.

**2. Lactic acid bacteria in dairy processing** 

up to 5 years (depending on variety).

J. Marcelino Kongo

http://dx.doi.org/10.5772/55937

**1. Introduction** 
