Effect of Purple-Colored Wheat Bran Addition on Quality and Antioxidant Property of Bread and Optimization of Bread-Making Conditions

Comparison of noodle-making performance of purple-colored whole wheat flour prepared with a jet mill and an ultra-centrifugal mill

This study explores the impact of milling methods on the quality and noodle-making performance by comparing jet-milled (WF-JM) and ultra-centrifugally milled (WF-UM) purple-colored whole wheat flours. WF-JM exhibits smaller starch granules and a fragmented protein matrix attributed to the increased milling pressure. Physicochemical analyses reveal lower moisture and higher damaged starch in WF-JM. Rheological analyses show lower viscosity in the WF-JM blends. The mixograph results reveal weaker dough-mixing stability and strength for WF-JM. Cooked noodles from WF-JM are uneven, in contrast to uniform WF-UM strands. Blending WF-UM enhances noodle quality. Overall, the noodle-making performance for WF-JM was inferior compared to WF-UM, confirming the significantly negative impact of damaged starch and fragmented protein matrix in whole wheat flour than the positive effect of particle size. This study highlights the complex interplay between milling methods, particle size, and physicochemical attributes, providing insights for optimizing whole wheat flour processing and product quality.

Combined Effects of Particle Size and Dough Improvers on Improving the Quality of Purple-Colored Whole Wheat Bread

Consumers' interest in healthy products is increasing. However, the production of excellent-quality whole wheat bread (WWB) faces challenges due to the reduced gluten functionality and varied particle sizes of whole wheat flour (WWF). This study aimed to explore the enhancement of purple-colored WWB quality by controlling the particle size of WWF and using dough improvers. Six purple-colored WWFs were obtained using an ultra-centrifugal mill with different sieve openings (0.5 and 1.0 mm) and rotor speeds (6000, 10,000, and 14,000 rpm). The average particle diameter (d50) of the smaller particle size group (S) and the larger particle size group (L) based on the sieve opening ranged from 115 to 258 μm and 294 to 492 μm, respectively. Group S demonstrated higher water absorption, damaged starch, and gluten strength compared to group L. Additionally, group S exhibited a greater bread volume and height compared to group L. Among the tested dough improvers (vital wheat gluten, vitamin C, enzymes, and emulsifiers), vital wheat gluten was the most effective in improving the quality of purple-colored WWB. The improvement effect was significantly greater in group S than in group L. These findings suggest that controlling the particle size of purple-colored WWFs and utilizing dough improvers can result in superior-quality WWB.

Rheological and fermentation properties of doughs and quality of breads from colored wheat varieties

The objective of this study was to examine the rheological and fermentation behavior of doughs prepared from five different colored wheat varieties (black AF Zora, yellow KM 111-18, purple AF Jumiko, blue AF Oxana and red Vanessa - chosen as a standard), which contain polyphenolics in the outer layers of grains. Three wholemeal flour fractions (fine, semi-coarse and coarse) were used for each variety. The flour fractions differed in the particle size of the bran, the ash content and thus the phenolic compound content. The baking trials, texture and sensory analyses of breads were performed, to assess their overall acceptability. The coarser granulation of flour fractions, average hardness (8.5<12.6<20.2 N) and chewiness (584<796<1053 N) of breads increased, while other parameters: springiness (90>87>77%), cohesiveness (78>75>70%) and resilience (35>32>27%) decreased. Moreover, the increase in off-flavors was detected with higher bran content. Regarding the flour granulation, the fine fraction seemed to be the most suitable due to its high gas-retention capacity. The best products in terms of both dough and bread quality reached blue AF Oxana and yellow KM 111-18. Utilization of colored wheat in bakery industry may present a good strategy of providing value-added products to the consumers.

Purple Wheat: Food Development, Anthocyanin Stability, and Potential Health Benefits

Colored wheats such as black, blue, or purple wheat are receiving a great interest as healthy food ingredients due to their potential health-enhancing attributes. Purple wheat is an anthocyanin-pigmented grain that holds huge potential in food applications since wheat is the preferred source of energy and protein in human diet. Purple wheat is currently processed into a variety of foods with potent antioxidant properties, which have been demonstrated by in vitro studies. However, the health impacts of purple wheat foods in humans still require further investigations. Meanwhile, anthocyanins are vulnerable molecules that require special stabilization treatments during food preparation and processing. A number of stabilization methods such as co-pigmentation, self-association, encapsulation, metal binding, and adjusting processing conditions have been suggested as a means to diminish the loss of anthocyanins in processed foods and dietary supplements. The present review was intended to provide insights about purple wheat food product development and its roles in human health. In addition, methods for stabilizing anthocyanins during processing were briefly discussed.

Quality of Low-Allergy Wheat ('O-Free') Flour and Optimization of Its Bread-Baking Performance

This study explored the quality of hypoallergenic wheat ('O-free') developed in Korea and optimized the basic ingredients and processing conditions for making 'O-free' bread using response surface methodology. Water and yeast amounts and mixing and fermentation times were selected as factors, and each factor's tested range was set by a central composite design using Design Experts: water 52-60 g, yeast 1.5-4.5 g, mixing time 2.5-5 min, and fermentation time 50-70 min. Bread height, volume, and firmness were analyzed to determine bread quality. Flour quality analysis showed that 'O-free' flour's gluten strength was weak. 'O-free' flour exhibited inferior bread-making performance compared to representative bread flour. Water and yeast amounts and mixing time, except for fermentation time, affected bread quality significantly. The interaction between yeast and fermentation also affected bread quality significantly. The optimized condition for making bread using 'O-free' flour is 60 g of water, 2.6 g of yeast, 2.5 min of mixing time, and 70.0 min of fermentation time. In conclusion, 'O-free' flour with the changed gluten composition showed poor gluten strength and bread-making performance. However, modifying the formulation of the basic ingredients and processing conditions could significantly improve the production of high-quality hypoallergenic bread.

Anthocyanin Content of Crackers and Bread Made with Purple and Blue Wheat Varieties

Purple and blue wheats contain anthocyanins in the outer layers of the wheat kernel, and therefore purple and blue wholemeals can be a source of anthocyanins when developing processed cereal products. However, cereal processing is anticipated to cause significant anthocyanin losses. In this study, the anthocyanin content of crackers and bread made from one purple and three blue wholemeals was measured during processing and after baking. LC-MS/MS was used to confirm the presence of anthocyanins, and to tentatively identify them. Mixing and baking steps significantly decreased the anthocyanin content, whereas resting and fermentation steps did not. Purple and blue wholemeal samples reacted differently, indicating that the starting anthocyanin content, localization and composition may have some impact on anthocyanin retention. Additionally, dough systems with decreased pH were more protective of anthocyanins during intermediate processing steps, as were high-temperature, short-time baking procedures. This research provides insights into the processing steps that cause significant anthocyanin losses, and proposes some modifications to formulation and processing conditions which can further reduce losses.

Special Issue “Cereal-Based Foods”

Published manuscripts about cereals have been increasing in numbers over the last 20 years by an average of 160 manuscripts per year [...]