Effect of natural flocculants on purity and properties of β-glucan extracted from barley and oat

Rheological Properties and Physical Stability of Aqueous Dispersions of Flaxseed Fibers

The main objective of this work is to investigate the influence of shear on the rheological properties and physical stability of aqueous dispersions of flaxseed fiber. The variable to consider will be the homogenization rate in two different rotor-stator homogenizers, Ultraturrax T50 or T25. In order to achieve the proposed objective, small amplitude oscillatory tests, flow curves, and multiple light scattering measurements were carried out. All samples exhibited a shear thinning behavior that was not influenced by the shear imposed, and a weak gel-like behavior. The latter, unlike the flow behavior, was sensitive to the homogenization rate. Thus, an increase in this variable caused a decrease in the viscoelastic moduli values. This result pointed out a weakening of the network formed by the flaxseed fiber in an aqueous medium. On the contrary, the physical stability improved. Nevertheless, all samples were highly stable. The homogenizer used was a significant variable. The shear negatively influenced the microstructure of the aqueous flaxseed fiber dispersions, although the obtained gels were highly stable. The gel-like behavior, the high viscosity at low shear rates, and the high physical stability of the samples studied make them interesting food stabilizers and thickeners.

Preparation of fat replacer utilizing gluten and barley β-glucan and the interaction between them

BACKGROUND

Fat replacers prepared from polysaccharides and proteins possess functional properties of both polysaccharides and proteins. In this study, an aqueous system of barley β-glucan (BBG) and gluten was prepared. The interactions between BBG and gluten (with/without extrusion modification) were studied. Triple analysis methods, including differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and low-field nuclear magnetic resonance (LF-NMR), were utilized to analyze the freezing-thawing and thermal evaporation process, as well as the distribution state of water. Meanwhile, fluorescence microscopic analysis, dynamic rheological analysis and electrophoresis analysis were used to study the structure and rheological properties of the system.

RESULTS

The results showed that BBG significantly increased the water-holding capacity of gluten, regardless of extrusion treatment, with the water absorption reaching about 4.8 to 6.4 times of its weight, which was 1 to 2.5 times higher than that without BBG. The triple analysis results suggested that BBG increased the binding capacity of the system to weakly bound water, hindered the aggregation of gluten and reduced the thermal decomposition temperature of the BBG and gluten composite system. After the gluten was extruded and homogenized with the BBG solution, the appearance of the composite system was more uniform and delicate.

CONCLUSIONS

In conclusion, BBG increased the water-holding capacity of the BBG and gluten composite system. With these changes, the composite system presented great potential for the preparation of polysaccharide-gluten fat replacer. © 2023 Society of Chemical Industry.

Development of Gluten-Free Muffins with β-Glucan and Pomegranate Powder Using Response Surface Methodology

More consumers are being diagnosed with celiac disease or diseases in which wheat products should be avoided. For this reason, it is important to increase the range of gluten-free products available. In this study, it was decided to optimize the technology for the creation of a muffin with β-glucan (BG) and pomegranate (PG), while establishing water share (WT), using the response surface methodology. It was shown that β-glucan and water had the most significant influence on specific volume and moisture (p ≤ 0.001). However, the increase of hardness, color, and total phenolic content (TPC) was mainly influenced by the increase of pomegranate content (p ≤ 0.01 for harness and color and p ≤ 0.001 for TPC). Consumers accepted products high in β-glucan more than high in pomegranate. Optimization ended with a composition that included 1.89% BG, 9.51% PG, and 77.87% WT. There were no significant differences between the model and the experimental sample, apart from higher consumer acceptability.

Effects of β-glucan and various thermal processing methods on the in vitro digestion of hulless barley starch

This study explored the effects of β-glucan and various processing methods on the digestion of hulless barley starch in vitro. The whole hulless barley showed significantly lower starch digestibility compared to that hydrolyzed by β-glucanase, indicating that β-glucan had inhibitory effects on starch digestion. However, β-glucan slightly accelerated the hydrolysis of extracted starch. Microscope observations of grains and flours revealed that the inhibitory effects of β-glucan benefited from the integral cellular structure of hulless barley. Besides, the hulless barley processed through flaking-roasting and stir-frying exhibited significantly lower starch digestibility (41.5% and 38.9%, respectively) and considerable intact cells and starch granules. The hulless barley processed by steam flash-explosion showed moderate starch digestibility (48.2%), which may be attributed to the encapsulation of starch-protein-β-glucan complexes. This elucidated the possible mechanism of β-glucan limiting the hydrolysis of hulless barley starch and provided useful direction to produce hulless barley products with desirable starch digestibility.

The impact of different levels of oat β-glucan and water on gluten-free cake rheology and physicochemical characterisation

The demand for new gluten-free (GF) products is still very crucial issue in food industry. There is also a need for bioactive compounds and natural alternatives for food additives. For now, not only providing structure without gluten is major challenge, but also high sensory acceptance and nutritional value are on the top. This study is focused on the effect of high-purity oat β-glucan as a structure-making agent on physicochemical and sensory properties of gluten-free yeast leavened cake. The response surface methodology (RSM) was used to set the design of the experiment. Water and oat β-glucan were chosen as independent variables. Enzymatic extraction was conducted in order to obtain pure oat β-glucan (approx. 85%). Physicochemical and microstructure analyses, and a consumer hedonic test were carried out to check the quality of the final product. As a last step, verification was undertaken to compare the predicted and experimental values of the results. The results showed that the optimisation process was crucial in obtaining high-quality, gluten-free yeast leavened cake. The optimised amounts of water and oat β-glucan were 66.12% and 2.63% respectively. This proves that the application of oat β-glucan to gluten-free products is possible and gives positive results in terms of texture, volume and sensory acceptance. Due to oat β-glucan’s pro-health benefits, the final product can be seen as a functional alternative for common gluten-free products in the market.

Microencapsulation of Camelina sativa Oil Using Selected Soluble Fractions of Dietary Fiber as the Wall Material

The aim of the study was to prove the usefulness of microencapsulation of Camelina sativa oil regarding its vulnerability to oxidation caused by oxygen, temperature, and other factors. Pectin, inulin, gum arabic, and β-glucan, each of them mixed with maltodextrin, were used as wall materials and their appropriability to reduce oxidation of the core material was examined. Microcapsules were prepared by spray drying, which is the most commonly used and very effective method. The research confirmed results known from literature, that gum arabic and inulin are most proper wall materials, because they ensure small oxidation increase during storage (4.59 and 5.92 eq/kg after seven days respectively) and also provide high efficiency of process (83.93% and 91.74%, respectively). Pectin turned out to be the least appropriate polysaccharide because it is not able to assure sufficient protection for the core material, in this case Camelina sativa oil, due to low efficiency (61.36%) and high oxidation (16.11 eq/kg after seven days). β-glucan occurred to be the coating material with relatively high encapsulation efficiency (79.26%) but high humidity (4.97%) which could negatively influence the storage of microcapsules. The use of polysaccharides in microencapsulation, except performing the role of wall material, has the advantage of increasing the amount of dietary fiber in human diet.

Beta-Glucan as Wall Material in Encapsulation of Elderberry (Sambucus nigra) Extract

The aim of the study was to investigate the potential of using β-glucan as wall material to microencapsulate the elderberry extract. Firstly, the extract was obtained by the water-acetone extraction method to extract mainly anthocyanins from ground dried fruits. The extract was mixed with wall materials: maltodextrin-β-glucan mixture and the control sample as a widely used combination of maltodextrin and arabic gum (92.5:7.5). In the examined samples the content of β-glucan was 0.5, 1, 2 and 3%. Properties of encapsulated extracts of final powders were measured using particle size and morphology, encapsulation efficiency, color measurement, total anthocyanin and ascorbic acid content (TAC and TAAC) methods. Our results indicated that the β-glucan wall material samples had higher process quality compared to control samples. Addition of β-glucan insignificantly decreases encapsulation efficiency. Among powders with β-glucan content, the powder with 1% β-glucan content was characterized by the smallest (24 μm) particle size. The sample with 2% β-glucan content had the highest water solubility and polydispersity index. Due to the encapsulation efficiency, moisture content, and water solubility index, the optimum condition of microencapsulation process for elderberry extract was for samples with 0.5% β-glucan as wall material content. To conclude, due to high molecular weight of β-glucan the higher than 0.5% ratio of β-glucan is not recommended for spray-drying method. However, small quantity of health-beneficial β-glucan could act as potential encapsulation agent in clean label products to replace Arabic gum.

Barley β-d-glucan - modified starch complex as potential encapsulation agent for fish oil

The aim of the study was to examine physicochemical characteristics of fish oil microcapsules produced at different temperatures and estimate the optimal ratio of BG, CS and spray drying temperature. Only the interaction between spray drying and β-d-glucan content played a significant role in influencing the encapsulation efficiency and spray drying itself (p ≤ 0.001 and p ≤ 0.05). Temperature played a significant role in increasing particle size as well, but the coefficient for this parameter was lower (0.179). The observed differences in particle size of microcapsules could be caused by the differences in glass transition temperature of the polymers (β-d-glucan and modified starch) used as wall material. It could be seen that the lowest TBARS content was observed when the β-d-glucan in the wall material was at relatively high level (85%) with moderate temperature applied (154 °C) - 0.56 mg of malonaldehyde/kg of powder. The highest amount of EPA was present in the sample with 50% share of β-d-glucan and spray dried in 150 °C (10.22 ± 0.24). After examination of all runs of the experiment, we have made optimization study to obtain the wall material composition and spray drying temperature values which will be most appropriate for fish oil encapsulation.