Integrated extrusion-enzymatic treatment of corn bran for production of functional cake

Extrusion Modification of Wheat Bran and Its Effects on Structural and Rheological Properties of Wheat Flour Dough

The study investigated the extrusion modification of wheat bran and its effects on structural and rheological properties of wheat flour dough. Extruded bran showed better solubility of dietary fiber and structural porosity, leading to higher hydration and swelling power. Addition of extruded bran to dough caused water redistribution as an intensive aggregation of bound water to gluten matrix with reduced mobility. The bran-gluten interaction influenced by water sequestering caused partial gluten dehydration and conversion of β-turn into β-sheet, which demonstrated the formation of a more polymerized and stable gluten network. Farinographic data confirmed the promotion of dough stability with extruded bran addition at lower gluten content, while viscoelastic data suggested improved dough elasticity at all gluten contents by increasing elastic moduli and decreasing loss tangent. This study would be useful for interpreting the modification effect and mechanism of extrusion on cereal brans and provide valuable guidance for applying it as an effective modification technology on the commercial production of cereal bran and its flour products.

Arabinoxylans as Functional Food Ingredients: A Review

The health benefits of fibre consumption are sound, but a more compressive understanding of the individual effects of different fibres is still needed. Arabinoxylan is a complex fibre that provides a wide range of health benefits strongly regulated by its chemical structure. Arabinoxylans can be found in various grains, such as wheat, barley, or corn. This review addresses the influence of the source of origin and extraction process on arabinoxylan structure. The health benefits related to short-chain fatty acid production, microbiota regulation, antioxidant capacity, and blood glucose response control are discussed and correlated to the arabinoxylan’s structure. However, most studies do not investigate the effect of AX as a pure ingredient on food systems, but as fibres containing AXs (such as bran). Therefore, AX’s benefit for human health deserves further investigation. The relationship between arabinoxylan structure and its physicochemical influence on cereal products (pasta, cookies, cakes, bread, and beer) is also discussed. A strong correlation between arabinoxylan’s structural properties (degree of branching, solubility, and molecular mass) and its functionalities in food systems can be observed. There is a need for further studies that address the health implications behind the consumption of arabinoxylan-rich products. Indeed, the food matrix may influence the effects of arabinoxylans in the gastrointestinal tract and determine which specific arabinoxylans can be included in cereal and non-cereal-based food products without being detrimental for product quality.

The Influence of the Pressure-Thermal Agglomeration Methods of Corn Bran on Their Selected Physicochemical Properties and Biogas Efficiency

The article presents the research made on the effects of methods of pressure-thermal agglomeration of corn bran, as well as the influence of processing parameters on selected physicochemical properties and biogas efficiency. Corn bran moistened to four levels of moisture content was used for the tests: 20%, 25%, 30% and 35% of dry matter. The pressure-thermal treatment was carried out with the use of a Brikol SJ25 pellet maker and a TS-45 single-screw extruder. In the tests of the extrusion-cooking process, three rotational speeds of the extruder screw were applied: 70, 90 and 110 rpm. The following characteristics were examined: efficiency of the extrusion-cooking and pelleting process, as well as the energy consumption. The water absorption index (WAI), the water solubility index (WSI), bulk density, kinetic strength, structure analysis by the ART/FTIR method, energy potential and the efficiency of cumulated biogas and cumulated methane per dry mass, as well as fresh mass and fresh organic matter and a series of microscopic pictures were completed. The analysis of the ATR/FTIR infrared spectra of the tested pelleted and extruded samples showed clear changes at the molecular level. Biogas production of extruded corn bran increased by several percent, as compared to untreated material.

The Sirtuin-1 relied antioxidant and antiaging activity of 5,5'-diferulic acid glucoside esters derived from corn bran by enzymatic method

Maize is the food crop with the highest total output in the world. However, corn bran is only a by-product with low price. The 5,5'-diferulic acid glucoside esters (DFG) were obtained from corn bran using the enzymatic method. DFG showed obvious antioxidant capacity in cell, Caenorhabditis elegans (C. elegans) and in mouse. DFG decreased ROS and MDA content in 500 μM H₂ O₂ stimulated ARPE-19 cells to 48.6% and 32.2%, respectively. DFG decreased ROS content in C. elegans to 49.1% and MDA content in acute ethanol (50%, 12 ml/kg) stimulated mouse to 30.4%. DFG also increased SOD protein content significantly in cell, C. elegans and mouse to 175.5%, 120.1%, and 126.2%, respectively. DFG significantly extended the lifespan of C. elegans both under heat stress and natural situation. The median survival time was prolonged to 133.3% and 116.7%, respectively. This capacity relied on the SIR-2.1 activity. SIR-2.1 is an ortholog of human Sirtuin-1 (SIRT-1). DFG also upregulated SIRT-1 and PCG-1α expression level obviously in H₂ O₂ -stimulated ARPE-19 cells (to 134.4% and 127.1%, respectively) and in acute ethanol stimulated mouse eyes (to 135.1% and 111.5%, respectively) and liver (to 123.3% and 113.6%, respectively). These results indicate that DFG has multiple bioactivities. Our research provides a new application prospect of corn bran. And to our best knowledge, this is the first time, the sirtuins-relied lifespan extension activity of the 5,5'-diferulic acid extracted from corn bran was reported. PRACTICAL APPLICATIONS: The traditional method for extracting diferulic acid from corn bran is to use the strong alkali. Obviously, this is not welcomed by the food industry. We employed the biological enzyme method in a relatively mild pH range during the extraction process. It is more environmentally friendly and more economical. DFG can be added as a raw material for functional foods like yogurt, fruit juice, and cereals. As well, the solid precipitate obtained after extraction can also be used as high-quality dietary fiber to produce functional food. Meanwhile, concerning for the 5,5'-diferulic acid derived from corn bran, the relevant research is still not abundant. And to our best knowledge, we have reported for the first time about the effect of this kinds of diferulic acid on prolonging life span and its SIRT-1-dependent activity. It also provides a new perspective for the study of diferulic acid.

Physicochemical and Morphological Properties of Extruded Adlay (Coix lachryma-jobi L) Flour

The effects of extrusion treatment on the structure and properties of adlay (Job’s tears) were investigated. Adlay flour was extruded through a twin-screw extruder with different parameters, including barrel temperature (80–160°C), moisture content (19–27%), and screw speed (170–330 rpm). The results showed that although the expansion index increased with increasing temperature, an increase in moisture content significantly decreased the EI (p<0.05). Extrusion improved the water solubility index and water absorption index of adlay flour (p<0.05). Furthermore, analysis of the gelating properties revealed that the structure and function of adlay flour had radically changed. After extrusion, the viscosity of the adlay flour decreased (peak viscosity decreased by more than 1000 cP), and its fluidity increased. The rheological data were modeled by the Herschel–Bulkley model. X-ray diffraction experiments showed that extrusion contributed to a decrease in relative crystallinity. Scanning electron microscopy revealed that extrusion damaged the basic structure of adlay flour, causing holes and pits on the extrudate surface. Compared to the native adlay flour, the extrusion resulted in significantly changing the pasting, gelating, thermal, rheological, and morphological properties of adlay flour. In conclusion, the extrusion can alter adlay characteristics, but it is necessary to choose appropriate conditions to attain the desired properties.