Simultaneous Optimization of Acetaldehyde and DMS Concentrations for Better Sensory Quality of Beer Fermented on an Industrial Scale.

The levels of selected volatile components that affected the sensory properties of a lager beer were optimized under high-gravity brewing conditions (15.5 °P) in an industrial plant. The influence of different pitching rates (6-10 million cells/mL), aeration levels (8-12 mg/L), times (4.5-13.5 h) of filling CCTs (cylindroconical tanks, 3850 hl), and fermentation temperatures (8.5-11.5 °C) on the contents of acetaldehyde, diacetyl, acetone, 2,3-pentanedion, dimethyl sulfide (DMS), and on the sensory properties of beer were investigated. Response surface methodology (RSM, Box-Behnken design) was used to research the possibilities for optimizing the concentration of selected volatile components and sensory properties of bottom-fermented lager beers. Statistical analyses of the results showed that the experimental factors had a significant influence (R-squared for the original model with no significant lack-of-fit) on some of the volatile components. Based on the Multiple Response Optimization analysis, the values of independent factors that ensured the highest beer sensory quality were the following: a pitching rate of 10 million cells per mL; a fermentation temperature of 11.5 °C; an aeration level of 12 mg/L; and a CCT filling time of 4.5 h. These results proved that RSM modelling can be successfully applied to optimize fermentation and lagering processes in an industrial plant to manufacture lagers of enhanced sensory quality.

The Impact of Phytases on the Release of Bioactive Inositols, the Profile of Inositol Phosphates, and the Release of Selected Minerals in the Technology of Buckwheat Beer Production.

A relatively high concentration of phytate in buckwheat malt, and the low activity of endogenous buckwheat phytases, both of which limit the effective use of substrates (starch, proteins, minerals) for fermentation and yeast metabolism, gives rise to the potential for application of phytases in beer production. This study aims at obtaining a 100% buckwheat wort with high bioactive cyclitols (myo-inositol and D-chiro-inositol) concentrations released by exogenous phytases and acid phosphatases. Two mashing programs were used in the study, i.e., (1) typical for basic raw materials, namely the well-established Congress method, and (2) optimized for phytase activity. The results indicated a nearly 50% increase in the level of bioactive myo-inositol and an 80% degradation of phytate in the wort as a result of simultaneous application of phytase and phosphatase enzymes in the mashing of buckwheat malt. In addition, high D-chiro-inositol concentrations were released from malt to the buckwheat wort. The concerted action of the two phytases significantly increased (19-44%) Zn2+ concentrations in wort. This may be of great importance during mash fermentation by Saccharomyces cerevisiae yeasts. There is a potential to develop technology for buckwheat beer production, which, in addition to being free from gluten, comprises high levels of bioactive myo- and D-chiro-inositols.

Solid-State Fermentation Reduces Phytic Acid Level, Improves the Profile of Myo-Inositol Phosphates and Enhances the Availability of Selected Minerals in Flaxseed Oil Cake.

Flaxseed oil cake was subjected to fermentation with Rhizopus oligosporus (DSM 1964 and ATCC 64063), and the phytate (InsP6) content, myo-inositol phosphate profile and in vitro bioavailability of essential minerals were studied. Flaxseed oil cake had a phytate mass fraction of 13.9 mg/g. A 96-hour fermentation of flaxseed oil cake by R. oligosporus DSM 1964 and R. oligosporus ATCC 64063 decreased the InsP6 content by 48 and 33%, respectively. The strains had different phytate-degrading activities: fermentation of flaxseed oil cake with R. oligosporus DSM 1964 was more advantageous, yielding InsP3-5 as a predominating myo-inositol compound, while fermentation with R. oligosporus ATCC 64603 produced predominantly InsP5-6. Solid-state fermentation of flaxseed oil cake enhanced in vitro bioavailability of calcium by 14, magnesium by 3.3 and phosphorus by 2-4%.

Phytase modulates ileal microbiota and enhances growth performance of the broiler chickens.

Phytase is well studied and explored, however, little is known about its effects on the microbial ecology of the gastrointestinal tract. In total, 400 one-day-old female Ross 308 chicks were randomly distributed to four experimental groups. The dietary treatments were arranged as a 2 × 2 complete factorial design, with the factors being adequate (PC) or insufficient calcium (Ca) and digestible phosphor (dP)(NC) and with or without 5000 phytase units (FTU)/kg of Escherichia coli 6-phytase. The gastrointestinal tract pH values, ileal microbial communities and short-chain fatty acid concentrations in the digesta were determined. The reduction in Ca and dP concentration significantly affected pH in the crop and caeca, and addition of phytase to the NC resulted in a pH increase in the ileum. The reduction in Ca and dP concentration significantly lowered, while phytase supplementation increased ileal total bacterial counts. Additionally, the deficient diet reduced butyrate- but increased lactate-producing bacteria. The addition of phytase increased Lactobacillus sp./Enterococcus sp. whereas in case of Clostridium leptum subgroup, Clostridium coccoides-Eubacterium rectale cluster, Bifidobacterium sp. and Streptococcus/Lactococcus counts, a significant Ca and dP level x phytase interaction was found. However, the recorded interactions indicated that the effects of phytase and Ca and dP levels were not consistent. Furthermore, the reduction of Ca and dP level lowered Clostridium perfringens and Enterobacteriaceae counts. The analysis of fermentation products showed that reducing the Ca and dP content in the diet reduced total SCFA, DL-lactate, and acetic acid in the ileum whereas phytase increased concentrations of these acids in the NC group. This suggests that P is a factor which limits fermentation in the ileum. It may be concluded that phytase plays a role in modulating the gut microbiota of chicken, however, this is clearly linked with the levels of P and Ca in a diet.

Phytases Improve Myo-Inositol Bioaccessibility in Rye Bread: A Study Using an In Vitro Method of Digestion and a Caco-2 Cell Culture Model.

Preparations of 6-phytase A (EC 3.1.3.26) and phytase B (acid phosphatase, EC 3.1.3.2) were applied alone and combined in the preparation of dough to estimate their catalytic potential for myo-inositol liberation from rye flour in the breadmaking technology. The experimental bread samples were ground after baking and subjected to determination of myo-inositol bioavailability by an in vitro method that simulated digestion in a human alimentary tract, followed by measurements of myo-inositol transport through enterocyte- -like differentiated Caco-2 cells to determine its bioaccessibility. Myo-inositol content was measured by a high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) technique. The concentration of myo-inositol in the dialysates of control bread was 25.3 µg/mL, whereas in the dialysates of bread sample baked with 6-phytase A, the concentration increased to 35.4 µg/mL, and in the bread baked with phytase B to 64.98 µg/mL. Simultaneous application of both enzymes resulted in myo-inositol release of 64.04 µg/mL. The highest bioaccessibility of myo-inositol, assessed by the measurement of the passage through the Caco-2 monolayer was determined in the bread baked with the addition of 6-phytase A. Enzymatically modified rye bread, particularly by the addition of 6-phytase A, may be therefore a rich source of a highly bioaccessible myo- -inositol.

Prostaglandin E2 supports growth of chicken embryo intestinal organoids in Matrigel matrix.

Investigating intestinal physiology in vitro remains challenging due to the lack of an effective primary enterocyte culture system. Recently developed protocols for growing organoids containing crypts and villus from adult mouse intestinal epithelium in Matrigel present an attractive alternative to the classical techniques. However, these approaches require the use of sophisticated and expensive serum-free medium supplemented with epithelial growth factor (EGF), Wnt agonist (R-spondin 1), and bone morphogenetic protein inhibitor (Noggin) in high concentrations. Here we demonstrate that is possible to use an isolated chicken embryonic intestinal epithelium to create such an organoid culture. Structures formed in Matrigel matrix in the first two days following isolation survive and enlarge during ensuing weeks. They have the appearance of empty spheres and comprise cells expressing cytokeratin (an epithelial cell marker), villin (a marker of enterocytes), and Sox-9 (a transcription factor characteristic of progenitors and stem cells of intestinal crypts). With chicken embryonic tissue as a source of organoids, prostaglandin E2 is as effective as R-spondin 1 and Noggin in promoting sustained growth and survival of epithelial spheroids.

In vitro efficacies of phosphorolytic enzymes synthesized in mycelial cells of Aspergillus niger AbZ4 grown by a liquid surface fermentation.

Activities of phytase, a pH 6.0 optimum nonspecific phosphomonoesterase and phosphodiesterase assayed toward bis(p-nitrophenyl)phosphate (phosphodiesterase I) and against p-nitrophenylphosphorylcholine (phosphodiesterase II), were partially purified from mycelial extracts of Aspergillus niger AbZ4 cultivated on a molasses medium by a liquid surface fermentation method. After elimination of phosphate from the medium, 7.3- and 3.5-fold enhancements in specific activities of phytase and phosphodiesterase II were observed. Efficacies of mycelial protein fractions in dephosphorylating a wheat-based broiler feed were determined in vitro according to a procedure that simulated digestion in the intestinal tract of poultry. The addition of 0.052 mg of protein from fractions, each of which was high in either pH 6.0 optimum phosphomonoesterase, phosphodiesterase I, phosphodiesterase II, or phytase per gram of a feed sample resulted in the enhancement of phosphorus release by 10, 11, 27, and 88%, respectively. In the presence of an excess of commercial phytase, the addition of the mycelial fraction high in phytase increased the dephosphorylation rate by 56%. The fraction high in phosphodiesterase II enhanced feed dephosphorylation by 8% in the presence of an excess of commercial phytase and commercial acid phosphatase.