No abstract

The aim of this study was to investigate the effect of transglutaminase (TG) addition on rheological properties, textural characteristics and microstructure of fermented milk products manufactured by different starters (probiotics and kombucha inoculum). Rheological analysis revealed that all manufactured fermented milk products had higher storage modulus than loss modulus and exhibited thixotropic and a typical shear thinning behavior. The addition of TG in milk increased approximately 10.5% hysteresis loop area, 39% firmness and 48% consistency in sample produced with probiotic starter and had more firm and stable gel structure than kombucha fermented milk products. The scanning electron microscopy micrographs showed that casein matrix of fermented milk products containing TG is continuous and uninterrupted except for void spaces occupied by milk serum and starter culture cell. PRACTICAL APPLICATIONSTransglutaminase (TG) is a transferase that forms inter-and intramolecular isopeptide bounds in and between many proteins by cross-linking of the amino acid residues of protein-bound glutamine and lysine. Among the dairy proteins, the casein fraction represents a favorable substrate for TG, mainly due to the highly accessible and flexible open chain structure. Heat treatment prior to crosslinking is necessary because the reactivity of TG is very low in unheated or pasteurized milk, despite the high reactivity of the casein. In the case of low-fat products, behavior of milk proteins during the gelation process is of particular importance. Cross-linking of preheated milk with reduced fat content results in improved gel firmness and reduced syneresis of acid-induced milk protein gels. Also, TG treatment at optimal technological parameters, pH value and temperature of milk, can solve these problems in kombucha fermented milk products, improving firmness, consistency and viscosity of gel. bs_bs_banner A journal to advance the fundamental understanding of food texture and sensory perception Journal of Texture Studies

Clinical proteomics, a rapidly growing field, intends to use specific diagnostic proteomic/peptidomic markers for initial diagnosis or prognosis of the progression of various diseases. Analyses of disease-associated markers in defined biological samples can provide valuable molecular diagnostic information for these diseases. This approach relies on sensitive and highly standardized modern analytical techniques. In the recent years, one of these technologies, CZE online coupled to MS (CZE-MS), has been increasingly used for the detection of peptide biomarkers (<20 kDa) in body fluids such as urine. This review presents the most relevant urinary proteomic studies addressing the application of CZE-MS in clinically relevant biomarker research between the years 2006 and 2014.

This study is concerned with the effect of kombucha starter culture on the rheological properties, texture and microstructure as well as on the protein fractions in different phases of milk fermentation. The results were compared with those obtained for the samples prepared with yoghurt and probiotic starters. Quality parameters in the course of fermentation at 42C were measured at the pH values of 5.4, 5.1, 4.8 and 4.6. The viscosity values measured at pH 5.4 indicate similarity of the gelation processes taking place in the samples involving kombucha and probiotics. The sample produced with kombucha had the highest value of complex modulus, which resulted in better rheological characteristics of the final product. The earlier onset of the gelation process induced significant differences among the samples in the microstructure at pH 5.4. The analysis of the protein profile revealed better stability of α and β casein fractions compared with the other protein fractions in particular phases of milk fermentation. PRACTICAL APPLICATIONSAlthough the method of scanning electron microscopy (SEM) has been already used to study the properties of the final product, the studies of the microstructural changes occurring in the course of yoghurt production are still lacking. As the application of kombucha in milk fermentation is still an attractive research topic, the authors found it interesting to include SEM into the set of methods for studying milk fermentation. Therefore, the objective of this research was to investigate the changes in the viscosity and texture during milk fermentation by a nonconventional starter -kombucha inoculum -and to establish the correlation of examined properties and the microstructure of the gel. The presented results represent a significant contribution to the understanding of the process of milk fermentation using different starter cultures related to the rheological characteristics of the gel. These characteristics and their changes are of significant practical importance for the process optimization and quality enhancement of new fermented milk product obtained by kombucha application.

The aim of this study was to examine the possibility of fermented dairy beverage production by the application of kombucha cultivated on thyme tea in combination with a probiotic starter and to evaluate the quality of the new functional product. Fermented dairy beverages are produced from milk with 1.6% milk fat at three fermentation temperatures: 37°C, 40ºC and 43ºC.Chemical quality, rheological properties and products of added starter cultures metabolism were determined in the fermented dairy beverages after production and after10 days of storage. Produced fermented dairy beverages have reduced milk fat content and good textural characteristics. Besides the highly valuable milk components, they contain numerous compounds which have pronounced therapeutic properties. These products could be used as functional food in the diet of different populations for health improvement