The contribution of superheated steam treatment of wheat flour to the cake quality

Heat-moisture treatment can modulate all-purpose wheat flour for short dough biscuit making: Evidences and mechanism

In view of the merits of all-purpose wheat flour (APWF) to soft wheat flour (SWF) in cost and protein supply, the feasibility of heat-moisture treatment (HMT, 19% moisture for 1 h at 60, 80 and 100 °C, respectively) to modify APWF as a substitute SWF in making short dough biscuits was explored. For underlying mechanisms, on the one hand, HMT reduced the hydration capacity of damaged starch particles by coating them with denatured proteins. On the other hand, HMT at 80 °C and 100 °C significantly denatured gluten proteins to form protein aggregates, highly weakening the gluten network in dough. These two aspects jointly conferred APWF dough with higher deformability and therefore significantly improved the qualities of biscuits. Moreover, the qualities of biscuits from APWF upon HMT-100 °C were largely comparable to that from SWF, even higher values were concluded in spread ratio, volume, specific volume and consumer acceptance.

Effect of superheated steam treatment on enzyme inactivation, morphostructural, physicochemical and digestion properties of sand rice (Agriophyllum squarrosum) flour

The lipase (LA) and peroxidase (POD) activities, as well as morphological structure, physicochemical and digestion properties of sand rice flour (SRF) treated with superheated steam (SS), were investigated. SS treatment at 165 °C completely deactivated LA and resulted in a 98% deactivation of POD activities in SRF. This treatment also intensified gelatinization, induced noticeable color alterations, and decreased pasting viscosities. Furthermore, there was a moderate reduction in crystal structure, lamellar structure, and short-range ordered structure, with a pronounced reduction at temperatures exceeding 170 °C. These alterations significantly impacted SRF digestibility, leading to increased levels of rapidly digestible starch (RDS) and resistant starch (RS), with the highest RS content achieved at 165 °C. The effectiveness of SS treatment depends on temperature, with 165 °C being able to stabilize SRF with moderate changes in color and structure. These findings will provide a scientific foundation for SS applicated in SRF stabilization and modification.

Development of Oleogel-Based Fat Replacer and Its Application in Pan Bread Making

In recent years, the bakery industry has been exploring alternative fats to replace traditional solid fats. Shortening, a common baking ingredient, is produced through the hydrogenation of vegetable oils, resulting in high levels of saturated and trans fatty acids, despite its vegetable oil origin. The excessive consumption of these fats has been associated with negative health effects, including dyslipidemia and cardiovascular issues. Oleogels, incorporating hydroxypropyl methylcellulose (HPMC), xanthan gum (XG), and olive oil, were utilized to replace shortening in the production of white pan bread. The substitution of shortening with oleogel in the white pan bread preparation demonstrated potential reductions in saturated fat, trans fat, and the ratio of saturated fat to unsaturated fatty acids. Specifically, with the complete substitution of shortening with oleogel, saturated fatty acids decreased by 52.46% and trans fatty acids by 75.72%, with unsaturated fatty acids increasing by 57.18%. Our findings revealed no significant difference in volume between bread made with shortening and bread with up to 50% shortening substitution. Moreover, when compared to bread made with shortening and 50% oleogel substitution, no adverse effects on the quality characteristics of volume and expansion properties were observed, and the retrogradation rate was delayed. This study suggests that incorporating oleogels, formed with hydrocolloids such as HPMC and XG, to replace shortening in bread, in conjunction with traditional solid fats, provides positive effects on the quality and nutritional aspects of the bread compared to using oleogel alone. Through this study, we demonstrate the use of oleogels as a healthier alternative to shortening, without reducing the bread's quality, thus offering a practical solution to reduce unhealthy fats in bakery products.

Effect of wheat roasting conditions and wheat type on short-wave infrared (SWIR) spectral data of whole and milled wheat by ANOVA-simultaneous component analysis

ANOVA-simultaneous component analysis (ASCA) was used to investigate the effect of roasting and wheat type on shortwave-infrared (SWIR) spectra of whole wheat and flour through assessment of statistical significance and characterisation of the contributing spectral features. The full factorial experimental design included two wheat types, three roasting temperatures and three roasting frequencies. SWIR spectral images were collected from the two roasted wheat types and their two milled samples. Three ASCA models, one for each wheat conformation (kernel, whole wheat flour, white flour) were investigated. It was evidenced that all factors and interaction in the whole wheat flour model had a significant (p ≤ 0.05) effect on spectral data. Only the factor roasting frequency was not significant in white flour model and only the interaction between roasting frequency and wheat type was not significant for the kernel model. The main variations in the loading line plots were identified and characterised by chemical structural differences that occur within the sample. The effect of roasting frequency had a more adverse effect on protein stability, moisture evaporation, water soluble carbohydrates and aromatic amino acids, compared to roasting temperature. A Rapid Visco-Analyser (RVA) was used to further investigate difference in wheat type as almost all spectral data sets differed significantly. The most prominent difference between the two wheat types was observed as differences in amylase activity and presence of lipids. ASCA applied to SWIR whole wheat and flour spectral data effectively characterised the significant effect of roasting on wheat starch and protein structures.

Comparison of milling methods on the properties of common buckwheat flour and the quality of wantuan, a traditional Chinese buckwheat food

The microstructural and techno-functional properties of buckwheat flour and its processability for making wantuan, as affected by different milling methods, were investigated. Results showed that the particle sizes (d(0.5)) of the flours made by stone-milling (SM), hammer-milling (HM), laboratory grinding with steaming pretreatment for 5 min (LG-5) and 10 min (LG-10) were 95.5, 111.5, 35.4 and 41.1 μm, respectively. Moreover, SM and HM flours had less liberated starch granules and 20.84%-24.32% higher relative crystallinity than LG-10 flour. Slurries of laboratory-grinded flours showed excellent suspension stability. LG-10 flour had lowest pasting viscosities but greatest storage modulus and loss modulus. Color differences among the wantuan made from different flours were not visibly perceived (ΔE < 5). Wantuan made from LG-5 flour exhibited highest textual quality due to its greatest resilience (0.376), good springiness (0.933) and accepted chewiness (1093.31). Concluding, steaming prior to grinding could improve the qualities of buckwheat flour for wantuan making.

Modification of Soft Wheat Protein for Improving Cake Quality by Superheated Steam Treatment of Wheat Grain

Many varieties of soft wheat in China cannot fully satisfy the requirements of making high-quality cakes due to their undesirable protein properties, which leads to shortages of high-quality soft wheat flour. Therefore, a modification of soft wheat protein is essential for improving the quality of soft wheat and thus improving cake quality. In order to modify the protein properties of soft wheat used for cake production, superheated steam (SS) was used to treat soft wheat grains at 165 °C and 190 °C for 1, 2, 3, 4, and 5 min, respectively, followed by the milling of wheat grains to obtain refined wheat flour. The properties of proteins and cakes were analyzed using refined wheat flour as materials. First, changes in the structures of wheat proteins were analyzed by determining the solubility, molecular weight distribution and secondary structure of proteins in wheat flour. Secondly, changes in the functional properties of proteins were analyzed by determining the foaming properties and emulsifying properties of proteins in wheat flour. Finally, the specific volume and texture of cakes with wheat flour milled from SS-treated wheat were analyzed. At the initial stage of SS treatment, some of the gliadin and glutenin aggregated, and the gluten macro-polymer (GMP) contents increased. This allowed a more stable gluten network to form during dough kneading, leading to an improvement in dough elasticity. In addition, a short time period (1-3 min) of SS treatment improved the emulsifying properties and foaming ability of wheat protein, which helped to improve the specific volume and texture of cakes. Increasing the SS temperature from 165 °C to 190 °C reduced the optimal treatment time needed to improve cake quality from 3 min to 1 min. SS treatment for longer time (>3 min) periods led to severe protein aggregation and a decrease in the foaming ability and emulsifying properties of protein, which led to a deterioration in the cake quality. Thus, SS treatment at 165 °C for 1-3 min and 190 °C for 1 min could be a suitable method of improving the physicochemical properties of soft wheat used to make cakes with high specific volumes and good texture.

Superheated steam processing of cereals and cereal products: A review

The concept of superheated steam (SS) was proposed over a century ago and has been widely studied as a drying method. SS processing of cereals and cereal products has been extensively studied in recent years for its advantages of higher drying rates above the inversion temperature, oxygen-free environment, energy conservation, and environmental protection. This review provides a brief introduction to the history, principles, and classification of SS. The applications of SS processing in the drying, enzymatic inactivation, sterilization, mycotoxin degradation, roasting, and cooking of cereals and cereal products are summarized and discussed. Moreover, the effects of SS processing on the physicochemical properties of cereals and the qualities of cereal foods are reviewed and discussed. The applications of SS for cereal processing and its effects on cereal properties have been extensively studied; however, issues such as the browning of cereal foods, thermal damage of starch, protein denaturation, and nutrition loss have not been comprehensively studied. Therefore, further studies are required to better understand the mechanism of the quality changes caused by SS processing and to expand the fields of application of SS in the cereal processing industry. This review enhances the understanding of SS processing and presents theoretical suggestions for promoting SS processing to improve the safety and quality of cereals and cereal products.

Effect of Thermal Treatment on the Physicochemical, Ultrastructural, and Antioxidant Characteristics of Euryale ferox Seeds and Flour

Euryale ferox seeds (EFS) were less gelatinized, preventing the release of nutrients and functional compounds, resulting in limited applications in meals and the food industry. Nutraceutical importance of EFS includes starch, protein, lipids, 20 amino acids, minerals, and vitamins (C, E, and beta carotene). This study aimed to evaluate the effect of three different thermal treatments on EFS’s physicochemical and nutritional properties and expected to improve its applicability. The results showed that the bulk density, thousand-grain weight, and hardness of thermal treated EFS were significantly decreased (p < 0.05), whereas the maximum decrease was observed in the industrial infrared heating-assisted fluidized bed (IHFH) treatment. Meanwhile, there were more crevices, fissures, and heightened porous structures in EFS between the pericarp and episperm and the endosperm after heat treatment, which facilitated grinding and water absorption. Notably, EFS’s water and oil absorption capacities increased significantly (p < 0.05) with microwave and IHFH treatments. EFS ground’s solubility into powder was increased significantly with thermal treatment (p < 0.05). Furthermore, the functional properties of TPC, TFC, DPPH radical scavenging activity, and reducing power were significantly increased (p < 0.05). In general, the changes in the physicochemical properties of EFS and increased bioactivity were caused by microwave and IHFH treatments. Hence, it might improve the food value of EFS while providing valuable information to researchers and food manufacturers.

Holistic View of Starch Chemistry, Structure and Functionality in Dry Heat-Treated Whole Wheat Kernels and Flour

Heat treatment is used as a pre-processing step to beneficially change the starch properties of wheat flour to enhance its utilisation in the food industry. Heat-treated wheat flour may provide improved eating qualities in final wheat-based products since flour properties predominantly determine the texture and mouthfeel. Dry heat treatment of wheat kernels or milled wheat products involves heat transfer through means of air, a fluidising medium, or radiation—often resulting in moisture loss. Heat treatment leads to changes in the chemical, structural and functional properties of starch in wheat flour by inducing starch damage, altering its molecular order (which influences its crystallinity), pasting properties as well as its retrogradation and staling behaviour. Heat treatment also induces changes in gluten proteins, which may alter the rheological properties of wheat flour. Understanding the relationship between heat transfer, the thermal properties of wheat and the functionality of the resultant flour is of critical importance to obtain the desired extent of alteration of wheat starch properties and enhanced utilisation of the flour. This review paper introduces dry heat treatment methods followed by a critical review of the latest published research on heat-induced changes observed in wheat flour starch chemistry, structure and functionality.