Properties of Hydrogel Materials Used for Entrapment of Microbial Cells in Production of Fermented Beverages

Abstract

Approaches using immobilized biological materials are very promising for application in different branches of the food industry, especially in the production of fermented beverages. Materials tested by our team for the process of entrapment belong to the family of charged polysaccharides able to form beaded hydrogels by ionotropic gelation (e.g. alginate, pectate, kappa-carrageenan) and synthetic polymers (e.g. polyvinyl alcohol) forming bead- and lens-shaped hydrogels by thermal sol/gel transition. Concentration of a gel, conditions and instrumentation of gelation process, bead and size distribution, porosity, diffusion properties, mechanical, storage and operational stability, and many other parameters were followed and optimized. Our work has been oriented especially to practical applications of immobilized cells. Brewing yeast cells were successfully immobilized by entrapment materials and used in a process of batch and continual production of beer, including primary and secondary fermentation of wort. Other applications include continual production of ethanol by fermentation of different saccharide substrates (molasses, glucose syrup, wheat hydrolysate), mead and non-alcoholic beverages production.

Hydrogels for Potential Colon Drug Release by Thiol‐ene Conjugate Addition of a New Inulin Derivative

“…The FT-IR spectrum of the INUDVSA derivative, compared to that of inulin, showed new bands due to the introduction of both DV and SA residues in the inulin backbone, such as bands at 1 737 cm À1 relating to C --O asymmetric stretching of ester groups, 1 316 cm À1 relating to sulfone (O --S --O) asymmetric stretching, 1 290 cm À1 relating to vinyl sulfone double bond (-C --CH 2 ) scissoring, an increase in the intensity of the peak at 1 136 cm À1 due to the overlapping of the sulfone symmetric stretching peak with a peak of inulin, and a band at 790 cm À1 relating to vinyl sulfone double bond (-C --CH 2 ) wagging. 1 …”

“…Pullulan (M w range 300-150 000 Da) was used as a standard. 1 H NMR (D 2 O) spectra were obtained using a Bruker AC-250 instrument.…”

“…The final product, named INUDV, was obtained with a yield of 92 wt.-%, based on starting inulin. It was then characterized by FT-IR, 1 H NMR and SEC analyses. Subsequently it was allowed to react with SA as follows.…”

“…This feature is principally due to the discovery and development of a large quantity of monomers and polymers to be used in their production. The application of hydrogels ranges over many fields: they have been proposed for use in the food industry, [1] as drug delivery systems, [2][3][4][5] biomaterials in tissue engineering and, most generally, in biomedical applications. [6,7] Hydrogels can be prepared from natural, [4,[8][9][10] synthetic [2,3,11] and mixed natural/synthetic polymers.…”

The Functional Quality of Soluble Recombinant Polypeptides Produced in Escherichia coli Is Defined by a Wide Conformational Spectrum

“…In inclusion bodies formed by enzymes, the associated enzymatic activity is sufficient for efficient in situ substrate processing. The proposal of biologically active inclusion bodies being usable as catalyzers (10) has resulted in the incorporation of diverse enzymes, in the form of inclusion bodies (including ␤-galactosidase, D-amino acid oxidase, maltodextrin phosphorylase, sialic acid aldolase, and polyphosphate kinase) (6,(11)(12)(13)(14)(15), into different types of enzymatic processes.The molecular organization and quality of the soluble protein population, which is generally believed to adopt the native, functional conformation, have been studied much less. Therefore, in this conventional view, soluble proteins are expected to show a rather narrow conformational spectrum and to be highly functional.…”