Emerging Technologies for Probiotic and Prebiotic Foods

In recent years, a number of new technologies has emerged as processing strategies alternative to the conventional thermal treatments; these include the use of Pulsed Electric Field (PEF), High Hydrostatic Pressure (HHP), High Pressure Homogenization (HPH), Ultrasounds, Oscillating Magnetic Fields and High-Intensity Light Pulses. Each technology is endowed with specific and sometimes unique advantages over the existing technologies in terms of microbial inactivation and/or effects on food constituents (i.e. proteins, naturally and microbial enzymes, vitamins, bioactive molecules and others). However, PEF, HHP and HPH, because already tested by food industry, and especially dairy sector, are the most promising for the production of functional and probiotic foods. Consequently, their possible applications in this field are deeply discussed. In fact, the scope of the present chapter is to integrate the available information, thereby providing an overall view on the actual situation and future of food processing and health promoting foods. However, the attention will be particularly focused on dairy products due to their role as functional foods and their ability as probiotic carriers. Also beverages such as fruit juices may represent an ideal delivery medium for probiotic cultures but few evidences, regarding the use of new technologies on probiotic juices, are available. In fact, the most of the literature deals with the application of novel technologies on probiotic milk, cheeses, yogurts and fermented milks. As far as probiotic meat based products, there are still some hurdles in developing and marketing novel probiotic products since such products are unconventional and consumers in many countries recognize meat and meat products to be bad for health. However accumulation of scientific data prove the increasing interest in this kind of product but the experimental evidences regard the item of the functional modification through i) the modification of fatty acid and cholesterol levels in meat, ii) the addition of vegetal oils to meat products, iii) the addition of soy, iv) the addition of natural extracts with antioxidant properties, v) the sodium chloride control, vi) the addition of fish oils, vii) the addition of fiber. For our Knowledge, no scientific evidence is reported for the production of probitic meat based product through HP processes. A grate interest has raised also for new technologies able to produce enzymes generating prebiotic compounds. For example, there is an increasing attention for the production and immobilization of β-Galactosidase which catalyses the formation of the prebiotic galacto-oligosaccharides.