Effect of Damaged Starch and Wheat-Bran Arabinoxylans on Wheat Starch and Wheat Starch-Gluten Systems

This study investigated the impact of damaged starch and arabinoxylans on the thermal and pasting behavior of mixtures containing starch and gluten. The mixtures containing starch, arabinoxylans, and gluten were dispersed in water and a 50% sucrose solution. When arabinoxylans were added to native starch in water, it did not modify the viscosity profiles. An increase in viscosity parameters was observed due to the addition of arabinoxylans to starch with a higher level of damage. Gluten did not influence the effects caused by arabinoxylans. In the sucrose solution, arabinoxylans caused an increase in the viscosity parameters of native starch and starch with higher damage content dispersions. Gluten caused greater viscosity increases when arabinoxylans were added. In water, the addition of arabinoxylans to native starch caused a decrease in the enthalpy of gelatinization and an increase in the onset temperature. Adding arabinoxylans to starch with a higher level of damage caused the opposite effects. In the presence of sucrose, arabinoxylans caused a decrease in the enthalpy of gelatinization. These results lay the foundations for studying the influence of damaged starch and arabinoxylans in water-rich systems characterized by the presence of substantial proportions of sucrose, such as batter formulations.

Effects of semidry milling on the properties of highland barley flour and the quality of highland barley bread

BACKGROUND

This study aimed to investigate the effects of semidry milling on the quality attributes of highland barley flour and highland barley bread. Highland barley flours were prepared by dry (DBF), semidry (SBF), and wet (WBF) milling methods. The properties of different highland barley flours were analyzed, and highland barley breads made from different highland barley flours were evaluated.

RESULTS

The results showed that WBF had the lowest damaged starch content (15.2 g kg^-1 ), and the contents of damaged starch in SBF-35 and SBF-40 (43.5 g kg^-1 and 24.1 g kg^-1 respectively) were lower than that of DBF (87.6 g kg^-1 ). And SBF-35 and SBF-40 with large particles exhibited low hydration performance. In addition, SBF-35 and SBF-40 had higher pasting viscosity, pasting temperature, ΔH, and relative crystallinity, consequently resulting in better gel properties than other highland barley flours. These properties could help SBF-35 and SBF-40 develop high-quality bread with large specific volume and superior crumb structure and texture that is similar to the bread with WBF.

CONCLUSION

Overall, semidry milling not only could improve the characteristics of HBF, but also avoid high starch damage by dry milling and water wasting by wet milling. What is more, highland barley breads with SBF-35 and SBF-40 had preferable appearance and crumb texture. Therefore, semidry milling could be regarded as a feasible way to produce highland barley flour. © 2023 Society of Chemical Industry.

Investigating the Contribution of Blending on the Dough Rheology of Roller-Milled Hard Red Wheat

The flour functionality and particle size distribution of wheat flour obtained on roller milling are dependent on the type of wheat, tempering conditions, and milling conditions. In this study, the impact of the tempering conditions (moisture and time) on the chemical and rheological properties of flour from blends of hard red wheat were analyzed. The wheat blends B1-25:75 (hard red spring (HRS)/hard red winter (HRW)), B2-50:50, and B3-75:25, which were tempered to 14%, 16%, and 18% for 16, 20, and 24 h, respectively, were milled using a laboratory-scale roller mill (Buhler MLU-202). Protein, damaged starch, and particle characteristics were influenced by blending, tempering, and milling streams. For all the blends, the protein content varied significantly among the break flour streams; the damaged starch content varied greatly in the reduction streams. The increased damaged starch content of the reduction streams proportionally increased water absorption (WA). Higher proportions of HRS in the blends significantly decreased the pasting temperature of the dough, as measured using Mixolab. Principal component analysis proved that the protein content was the key determinant in particle characteristics, WA, and pasting properties of the flour, especially in blends with a higher proportion of HRS.

Influence of damaged starch on thermal and rheological properties of wheat starch and wheat starch-gluten systems in water and sucrose

BACKGROUND

The granular integrity of starch granules is affected by the mechanical action of the milling-process, thus producing what is called damaged starch (DS). The effect of DS on bakery products was extensively studied, but there is not much information about the effect of this minor flour component on batter-type products in which there is a high amount of sucrose. The objective of this work was to study the influence of damaged wheat-starch on starch and starch-gluten systems dispersed in water and sucrose 500 g kg^-1 solution.

RESULTS

Thermal and pasting properties and the viscoelastic behavior of the systems were evaluated. Gelatinization enthalpy decreased when DS amount increased in the samples in both solvents. In starch-gluten systems, the degree of influence of DS on the gelatinization enthalpy was solvent-dependent. The presence of gluten minimized the effect of DS on the gelatinization process in water. The viscosity profile of starch and starch-gluten samples was reduced in both solvents when DS level increased. The influence of DS on the viscosity profile was solvent-dependent in starch-gluten systems. The presence of gluten lessened the influence of DS on the viscosity profile during the pasting process in sucrose solution. Higher DS levels decreased the viscoelastic behavior of the systems in both solvents and further reduced the viscoelastic behavior of the systems in sucrose solution.

CONCLUSION

These results contribute to understanding the influence of the DS levels on the batter properties of flour-based batter-type products, mainly those generated on starch and gluten-starch systems dispersed in sucrose solution. © 2022 Society of Chemical Industry.

Stone Milling versus Roller Milling in Soft Wheat (Part 2): Influence on Nutritional and Technological Quality of Products

Wholegrain soft wheat flours can be obtained by either roller milling or stone milling. In this paper, we report on the continuation of a study aimed at analysing compositional and technological differences between differently milled wholegrain flours. Eight mixes of soft wheat grains were stone milled and roller milled and the milling products analysed for their phytic acid, lipids composition to determine the presence of trans-fatty acids and damaged starch. A wholegrain flour milled with a laboratory disk mill was also analysed as comparison, as well as seven wholegrain flours purchased on the market. For phytic acid we found that that there is no compositional difference between a stone milled or a roller milled flour if the milling streams are all recombined: the milling streams instead have different amounts of phytic acid which is mainly present in the fine bran and coarse bran. It was not possible to highlight differences in the milling technology due to the presence of trans-fatty acids in the stone milled wholegrain flour whereas it was possible to find that starch damage depended on the milling method with stone milled wholegrain flours having in all cases significantly higher values than the roller milled ones.

Ultrafine grinding of wheat flour: Effect of flour/starch granule profiles and particle size distribution on falling number and pasting properties

In the present paper, the properties of different ultrafine flour samples, including particle size distribution, damaged starch content, falling number, and pasting properties, were examined. The results indicated that the particle size decreased significantly after jet milling, as the rotation speed and grinding time increased, and the damaged starch content significantly increased as the size of the flour/starch decreased; this is in contrast to the significant decrease in falling number. Significant differences in pasting temperature were observed between straight-grade flour (68.6°C) and five ultrafine flour samples (from 86.3 to 87.9°C). We also observed significant increases in peak viscosity, trough, breakdown viscosity, final viscosity, and setback as the flour particle size decreased from 43.07 µm to 25.81 µm (D50). The same parameters significantly decreased as the flour particle size decreased from 25.81 µm to 10.15 µm (D50). Correlation analysis identified a significant negative correlation between flour particle size (D50) and damaged starch content and pasting temperature, while a significant positive correlation was found with the falling number values. The results of this work may have an important impact on the quality of processed foods.

Effect of Heat-Moisture Treatment on Physicochemical, Thermal, Morphological, and Structural Properties of Mechanically Activated Large A- and Small B-Wheat Starch Granules

The large and small granules of A-starch (AS) and B-starch (BS) were separated from wheat cultivar of ZM 22. It was modified by ball-milling (BM) and heat-moisture treatment (HMT) was performed after BM treatment. After BM, noticeable deformation, fragments, fissures, and grooves were observed, whereas diffusion and aggregation were detected and followed by HMT. Crystallinity of AS-BM-5h decreased to 7.8%, and no diffraction peaks were observed for BS. However, after HMT, the crystallinity of AS-BM-5h and BS-BM-5h was increased to 17.4% and 6.2%, respectively. AS-BM-HMT displayed better thermal stability. After being treated by BM previously, AS and BS showed an increase in solubility, whereas the subsequent HMT of BM-treated starches (both AS and BS) had higher solubility especially for BS with longer BM treatment time. Large-sized granules were easier to be damaged by BM, whereas small-sized granules were greatly influenced by HMT. Dual modification of BM-HMT was an effective and potential method to modify the structure of wheat starch granules and expand its industrial applications. PRACTICAL APPLICATION: This study put forward a new dual modification method in combination with BM-HMT for large A-starch and small B-starch granules. Flour processing inevitably causes some starch to be damaged by destroying the structure. How can the damaged starch structure be improved to satisfy the food processing industry? HMT was proposed to modify the mechanically activated starches because of its obvious effects on smaller BS. HMT can reduce the content of damaged starch by rearranging and reorganizing its structures. This study can provide a low-cost, convenient, and eco-friendly technology for improving damaged starch and developing its applications in food industry.

Intact and Damaged Wheat Starch and Amylase Functionality During Multilayered Fermented Pastry Making

The roles of native and damaged starch (DS) during fermented pastry making were examined by increasing the level of DS in wheat flour by ball-milling and/or by including amylase in the recipe. Increased DS levels increase laminated dough strength presumably by making less water available for the gluten. This effect was partly overcome by amylase use. During baking, a reduced resistance of the dough to gas cell expansion, as a result of enzymatic starch hydrolysis, seems responsible for increased pastry lift and improved crumb structure. Gelatinization of intact starch limits dough lift and expansion. Even at high amylase dosages structural collapse was limited, which suggests a significant role for gluten in pastry product structure formation. Differential scanning calorimetry and low-resolution ¹ H nuclear magnetic resonance experiments indicated that increased levels of starch damage and amylase use impact the amylose network in the product and respectively increase and decrease the extent to which amylopectin retrogrades during storage.

PRACTICAL APPLICATION

This research article evaluates the role of intact and damaged wheat starch during the production of fermented pastry products. An expanded knowledge on starch functionality during the different pastry production steps allows for a targeted selection of additives to improve product quality and production efficiency. The results obtained in this study can contribute to the realization of industrially feasible solutions for the production of quality pastry products.

Solvent Retention Capacities of Oat Flour

This study measured the solvent retention capacities (SRCs) of flours from eight oat varieties and one wheat variety against different solvents to explore the swelling volume of oat flour with different solvents, and thus provide a theoretical basis for quick β-glucan analysis. The SRC profile consists of water SRC (WSRC), 50% sucrose SRC (SSRC), 5% lactic acid SRC (LASRC), 5% Na₂CO₃ SRC (SCASRC), NaCl SRC (SCSRC), CaCl₂ SRC (CCSRC), FeCl₃ SRC (FCSRC), sodium cholate SRC (SCHSRC), NaOH (pH 10) SRC (SHSRC), Na₂CO₃ (pH 10) SRC (SCABSRC) and SDS (pH 10) SRC (SDSSRC) values, and a Chopin SRC kit was used to measure the SRC value. SRCs of the oat flours increased when the solvents turned from neutral (water and NaCl) to acidic (5% lactic acid) or alkaline (5% Na₂CO₃, CaCl₂, FeCl₃, NaOH and pH 10 Na₂CO₃), and rose as the metal ion valencies of the metal salts (NaCl, CaCl₂ and FeCl₃) increased. The β-glucan contents were significantly positively correlated with the SCSRC (0.83**), CCSRC (0.82**), SCHSRC (0.80**) and FCSRC (0.78*). SRC measurements of β-glucan in oat flours revealed that the CCSRC values were related with β-glucan (0.64*) but not related with protein and starch. CaCl₂ could therefore potentially be exploited as a reagent for β-glucan assay.

Use of enzymes to minimize the rheological dough problems caused by high levels of damaged starch in starch-gluten systems

BACKGROUND

During wheat milling, starch granules can experience mechanical damage, producing damaged starch. High levels of damaged starch modify the physicochemical properties of wheat flour, negatively affecting the dough behavior as well as the flour quality and cookie and bread making quality. The aim of this work was to evaluate the effect of α-amylase, maltogenic amylase and amyloglucosidase on dough rheology in order to propose alternatives to reduce the issues related to high levels of damaged starch.

RESULTS

The dough with a high level of damaged starch became more viscous and resistant to deformations as well as less elastic and extensible. The soluble fraction of the doughs influenced the rheological behavior of the systems. The α-amylase and amyloglucosidase reduced the negative effects of high damaged starch contents, improving the dough rheological properties modified by damaged starch. The rheological behavior of dough with the higher damaged-starch content was related to a more open gluten network arrangement as a result of the large size of the swollen damaged starch granules.

CONCLUSION

We can conclude that the dough rheological properties of systems with high damaged starch content changed positively as a result of enzyme action, particularly α-amylase and amyloglucosidase additions, allowing the use of these amylases and mixtures of them as corrective additives. Little information was reported about amyloglucosidase activity alone or combined with α-amylase. The combinations of these two enzymes are promising to minimize the negative effects caused by high levels of damaged starch on product quality. More research needs to be done on bread quality combining these two enzymes. © 2015 Society of Chemical Industry.

Influence of Psyllium, sugar beet fibre and water on gluten-free dough properties and bread quality

Celiac patients generally have a low intake of protein and fibre attributed to their gluten-free (GF) diet. To satisfy the increasing demand for healthier products, this research focused on the effects of the supplementation of Psyllium (P) and sugar beet fibre (SB) on the mixing and leavening behaviour of gluten-free doughs. Four doughs, having different consistencies that made them suitable to be poured into moulds or to be shaped, and their corresponding breads were evaluated. The results obtained suggested that a lower consistency is preferred to assure good dough performances during leavening, in particular when ingredients having a high water affinity are included into the recipe. Both P and SB improved the workability of the doughs, but P played a central role on GF bread development, thanks to its film forming ability, and evidenced a more effective antistaling effect, thanks to its high water binding capacity.