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To investigate the impact of superfine grinding of wheat bran on bread quality, antioxidant and nutritional properties, bran with different particle sizes (coarse, D 50 of 362.3 μm; medium, 60.4 μm; superfine, 11.3 μm) were produced and fortified to white bread at three levels (10, 20 and 30%). At 20% fortification, compared to coarse bran, superfine bran increased the hardness and reduced the brightness of bread crumb by 56.3 and 3.30%, respectively, while it decreased bread's cell size by 10.7% and insignificantly impacted on bread's specific volume and porosity. Superfine bran retarded bread staling by 8.3% than coarse bran. It resulted in significantly better sensory attributes of bread in taste, texture and general palatability, and the fortified bread was overall acceptable (score > 6). Moreover, faster release of antioxidants (285-353% higher k), slower release of glucose (10.8% lower k), 3.76% less rapidly digestible starch, 5.65% more slowly digestible starch and 13.2% more resistant starch were found in the superfine group than the coarse one. Results demonstrated the potential of 20% fortification of superfine bran in developing fibre-enriched bread with satisfactory quality, increased antioxidant property and improved glycaemic modulation., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The aim of this study was to investigate the impact of wheat bran fortification on the mastication process of bread. White wheat bread (WB) and bran-fortified wheat bread (BB) were consumed by eighteen panellists. The bolus was collected at four different mastication stages and characterized by properties of hydration, particle size, and texture. The results showed that there was no difference between the two bread samples in terms of swallowable bolus moisture. BB with a harder and denser texture produced more small particles and had a slightly shorter chewing time than WB during mastication. Moreover, bolus heterogeneity ( D 75 / D 25 ) indicated a distinct difference among mastication stages and revealed different disintegration pathways between the two samples: BB bolus exhibited a monotonous particle size reduction during mastication with reducing D 50 and D 75 . It was concluded that bran fortification changed the bread breakdown pathways in terms of bread disintegration and bolus formation during the mastication process. This information offers new guidelines for fortifying innovative materials to manufacture foods specifically targeted for health.D 25 ; whereas, WB displayed a combination pattern of disintegration and agglomeration featuring relatively steady D 50 and fluctuating D 75 / D 25 . It was concluded that bran fortification changed the bread breakdown pathways in terms of bread disintegration and bolus formation during the mastication process. This information offers new guidelines for fortifying innovative materials to manufacture foods specifically targeted for health.

This study aimed to investigate the effect of wheat bran micronization on its functionality including physicochemical and antioxidant properties, and dough properties. Coarse bran (D 50  = 362.3 ± 20.5 μm) was superfine ground to medium (D 50  = 60.4 ± 10.1 μm) and superfine (D 50  = 11.3 ± 2.6 μm) bran, accompanied with increasing specific surface area and breakdown of aleurone layers. Bran micronization increased its soluble dietary fibre content, ferulic acid liberation, and antioxidant properties including total polyphenol content, ABTS•+ and DPPH• scavenging activities, while decreased its water retention capacity and insoluble dietary fibre content. Moreover, bran micronization impacted dough rheological properties. The dough with superfine bran had higher water absorption and gelatinization temperature, peak viscosity, final viscosity and setback value, lower stability time, resistance to extension, and extensibility than the dough with coarse bran. This dough furthermore exhibited more solid-like properties characterized by decreased loss moduli and frequency dependence (n')., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Whole-wheat flour (WWF) is increasingly popular because of the health benefits of whole grains. This study investigated the effect of WWF particle size on dough properties, bread quality and in vitro starch digestibility. WWF was made from intact whole grain directly. Three WWF particle sizes were examined, including coarse, medium and fine with a mean size of 1315, 450 and 199 μm, respectively. The dough made from WWF of a larger particle size exhibited lower extensibility and stability, and subsequently the bread had a more compact structure (i.e. lower open porosity and thicker cell thickness), smaller specific volume and harder texture, which were regarded as poor quality attributes. On the other hand, the bread made from the fine WWF exhibited a higher amount of released glucose than those made from the coarse and medium WWFs. Moreover, the particle size of bread bolus showed no significant effect on in vitro starch digestion. The whole study demonstrated that the particle size of WWF plays a critical role in determining both bread quality and digestibility.

This study aimed to understand the impact of in vitro oral processing methods on bolus formation and the kinetics of starch hydrolysis of refined white bread during in vitro gastrointestinal digestion. Four in vitro oral processing methods (i.e., cut, cut-and-pestle, blend, and grind) were performed at two levels of disintegration (less and more intensive) and compared with human mastication. Boluses prepared using the in vitro methods had a larger particle size (20-69 mm 2 vs. 14 mm 2 ), a higher moisture content (64-68% vs. 47%), a softer texture (1.3-2.3 N vs. 6.3 N) and a less adhesive surface (0.3-1.0 vs. 1.6 N•s) as compared to the in vivo masticated ones. Moreover, in vitro prepared blouses were digested more rapidly than in vivo masticated ones during the stimulated intestinal digestion from 150 min onward, with a higher hydrolysis rate (0.011-0.012 mg/mL • min vs. 0.010 mg/mL • min) and a higher equilibrium concentration of reducing sugar (5.5-6.3 mg/mL vs. 4.9 mg/mL). Among all the in vitro methods, the blending and grinding methods produced boluses that most closely resemble the in vivo masticated ones in terms of their physical characteristics. The blending method also produced boluses having the highest amount of reducing sugar released (6.32 mg/mL). The amount of reducing sugar present in the PBS buffer outside the dialysis tube might be controlled by the diffusion efficiency at the beginning of the digestion (≤120 min) and then be largely influenced by the particle size of the bolus in the latter stage of the digestion. PRACTICAL APPLICATION: Studying the in vitro starch amyloysis is valuable for predicting the postprandial glycemic potential of starchy food. This work provides novel insights on the role of in vitro oral processing in the prediction of the glycemic potential of carbohydrate-rich staple food. Blending method is recommended because of its ability to produce boluses with similar physical characteristics as the in vivo masticated boluses. But the excessive structural breakdown occurred during blending also resulted in a higher enzymatic accessibility and a higher rate of starch digestion. Further study is needed to propose a new in vitro method that stimulates multiple actions occurred during mastication (cutting, grinding, and shearing), in order to match both physical properties and digestion profiles. Moreover, the amount of artificial saliva added should be adjusted according to the specific type of food., (© 2019 Wiley Periodicals, Inc.)