Probiotic strains are claimed to confer health benefits to human organisms when consumed in adequate amounts. Thus, over the last decades there has been an increased interest in the production of functional foods containing probiotic bacteria. However, in order to display optimal probiotic functionality, these bacteria should survive through the gastrointestinal tract (GI) in high populations, reaching 10⁶–10⁷cfu (colony-forming unit)/g or mL at the end of product’s shelf life. The food products that can be used as probiotic bacteria carriers exhibit limitations concerning the viability of the cells, associated with parameters such as the acidity of the food matrices or their processing and storage conditions. Moreover, the acid environment of the GI system may be crucial for their survival. Thus, techniques such as microencapsulation and enrichment with prebiotic substances are proposed for their protection. Aim of this review is to present the bacterial strains exhibiting probiotic properties, the microencapsulation techniques which are applied for their protection, as well as their advantages and disadvantages. Finally, the characteristics of the most important food products that have been used as possible matrices for microencapsulated probiotic cells are described.

Milk and yogurt are important elements of the human diet, due to their high nutritional value and their appealing sensory properties. During milk processing (homogenization, pasteurization) and further yogurt manufacture (fermentation) physicochemical changes occur that affect the flavor and texture of these products while the development of standardized processes contributes to the development of desirable textural and flavor characteristics. The processes that take place during milk processing and yogurt manufacture with conventional industrial methods, as well as with innovative methods currently proposed (ultra-high pressure, ultrasound, microfluidization, pulsed electric fields), and their effect on the texture and flavor of the final conventional or probiotic/prebiotic products will be presented in this review.

Lactic acid fermentation during the production of skim milk and whole fat set-style yogurt was continuously monitored by measuring pH. The modified Gompertz model was successfully applied to describe the pH decline and viscosity development during the fermentation process. The viscosity and incubation time data were also fitted to linear models against ln(pH). The investigation of the yogurt quality improvement practices included 2 different heat treatments (80 degrees C for 30 min and 95 degrees C for 10 min), 3 milk protein fortifying agents (skim milk powder, whey powder, and milk protein concentrate) added at 2.0%, and 4 hydrocolloids (kappa-carrageenan, xanthan, guar gum, and pectin) added at 0.01% to whole fat and skim yogurts. Heat treatment significantly affected viscosity and acetaldehyde development without influencing incubation time and acidity. The addition of whey powder shortened the incubation time but had a detrimental effect on consistency, firmness, and overall acceptance of yogurts. On the other hand, addition of skim milk powder improved the textural quality and decreased the vulnerability of yogurts to syneresis. Anionic stabilizers (kappa-carrageenan and pectin) had a poor effect on the texture and palatability of yogurts. However, neutral gums (xanthan and guar gum) improved texture and prevented the wheying-off defect. Skim milk yogurts exhibited longer incubation times and higher viscosities, whereas they were rated higher during sensory evaluation than whole fat yogurts.