Mariangela Gallo

Use of alginate beads as carriers for lactic acid bacteria in a structured system and preliminary validation in a meat product.

This paper proposes the microencapsulation into alginate beads of 4 isolates of lactic acid bacteria (Lactobacillus spp.), previously isolated from pork meat. First, the beads were studied in relation to the encapsulation yield (EY), kinetic of cell release in a structured system, and survival throughout bead storage at 4 °C. EY was 93-96% and the survival of the encapsulated microorganisms was variable, with two isolates showing a bacterial population of 6.1-6.9 log cfu/g after 35 days under refrigerated conditions. Thereafter, the paper addressed a preliminary validation in a meat model system, containing salt, nitrites and nitrates, lactose, pepper, and then in a commercial preparation of pork meat. For the validation in pork meat, free cells were used as controls. Cell released from beads were able to achieve a significant acidification; in particular, after 7 days they showed the same results of free cells.

Novel Microbial Immobilization Techniques

Immobilization technologies preserve cells (bacteria, yeasts), both starter and probiotics, in food and during the transit through the gastrointestinal tract. Until today, several immobilization methods have been proposed and studied namely extrusion, emulsion, spray drying, and coacervation.

Encapsulation of Active Compounds in Fruit and Vegetable Juice Processing: Current State and Perspectives

The production of value-added and/or functional juices has increased significantly in recent years, following an increased consumer demand to promote health and/or prevent disease through diet and nutrition. Micro and nano-encapsulation are promising technologies to protect and deliver sensitive compounds, allowing a controlled release in the target sites. This paper offers an overview of current applications, limits and challenges of encapsulation technologies in the production of fruit and vegetable juices, with a particular emphasis on products derived from different botanical sources.

Chapter 5 – Yeasts

Yeasts are eukaryotic organisms that are included in a group of organisms called “fungi,” which also includes molds and mushrooms. Yeasts can have both positive and negative effects on fermented products consumed by humans and animals. Yeasts are used as starter cultures in cheeses and bread, as well as wine, beer, and other alcoholic fermentation products, but they can also initiate spoilage in foods, such as yoghurt, fruit juice, salads, and mayonnaise. A group of authors have published a list of yeasts that are frequently associated with the spoilage of foods and beverages: to these lists of “dangerous” spoiling yeasts four other yeast species have also been added, which were the members of the “second-division spoiling yeasts.” The ability of some yeasts to survive in harsh conditions makes them potent food spoilage organisms responsible for large economic losses of some food products.