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

Study on the prebiotic effects of insoluble crude and fine fibers of wheat bran after simulated digestion in vitro

This study aims to evaluate the probiotic effects of insoluble crude and fine fibers of wheat bran on the intestine after simulated in vitro digestion. It was found that the particle size distribution of modified fine wheat bran (MWB) was significantly smaller than that of natural crude wheat bran (NWB). MWB had a looser texture and more porous structure. The dry matter digestibility and organic matter digestibility of MWB were 58.60 % and 59.05 %, which were significantly higher than that of NWB (53.64 % and 54.13 %). More SDF and free polyphenol were released from the MWB. At 12 h of fermentation, the SDF content of the MWB was 3.76 g/100 g, significantly higher than NWB (3.40 g/100 g), and the free polyphenol was 9.43 mg/g, significantly higher than NWB (9.01 mg/g). The content of short-chain fatty acids including formic acid, acetic acid, propionic acid, butyrate acid and valerate acid in the samples were significantly higher in MWB than in NWB. Analysis of the microbial flora structure and diversity of the fermentation samples revealed that the relative abundance of Lactobacillus was higher in the MWB group, and was closer to the oligofructose group (FOS) in terms of functional predictions.

Rheological Characteristics of Wheat Dough Containing Powdered Hazelnuts or Walnuts Oil Cakes

This study assessed edible oil industry byproducts, oil cakes (OC) based on hazelnuts and walnuts (HOC, WOC), to replace wheat flour dough (WD) based on farinograph and extensograph parameters and rheological measurements. The research hypothesis of this work is that replacing part of wheat flour with ground nut oil cakes modifies the rheological characteristics of the dough. WF was replaced at the level of 5%, 10% and 15%. It was shown that use of OC in flour mixtures at various levels significantly influenced the rheological properties of the dough. The water absorption of wheat flour and oil cake mixtures was higher than that of the control sample, and the average value of this indicator was 53.4%. The control sample had the lowest dough development time (DDT), and the presence of HOC or WOC in the system resulted in a significant increase in this parameter (p < 0.05). The average DDT of WDHOC cakes was 4.7 min and was lower compared to WDWOC which was 5.9 min. The WDWOC10% and WDWOC15% samples were characterized by the highest dough stability value and the lowest degree of softening (p < 0.05). The presence of OC in the flour mixtures increased the values of the storage and loss moduli, which was reflected in the K' and K″ values. The values of these parameters also increased as the level of OC addition increased. WDHOC doughs were characterized by higher values of the K' and K″ parameters compared to WDWOC. The results of the creep and recovery test showed that the dough with the addition of nut OC was less susceptible to deformation compared to the control dough (p < 0.05). The resistance to deformation increased with the increasing share of HOC or WOC in the mixtures. The average value of viscoelastic compliance (J1) of this parameter for WDHOC dough was on average 1.8 × 10-4 Pa-1, and for WDWOC 2.0 × 10-4 Pa-1. Nut oil cakes are an interesting technological addition to the dough. Their use may have a positive impact on the characteristics of the finished product and expand their application possibilities in the food industry. This is because the dough with the addition of nut cakes was more stiff and less flexible and susceptible to deformation.

The Rheology and Textural Properties of Bakery Products Upcycling Brewers' Spent Grain

This study aimed to evaluate the rheological properties of doughs with 50% brewers' spent grain (BSG) derived from a rye-based (RBSG) and barley-based (BBSG) beer added, and the textural profile of the related baked products. Simple model systems using BSG flour mixed with water were studied. Two bakery products, focaccia and cookies, were made as food systems using BSG in a 1:1 ratio with wheat flour (WF). Their rheological properties and texture after baking were characterized. BSG-added dough exhibited viscoelastic properties with a solid gel-like behavior. The addition of BSG increased G' > G″ and decreased the dough flexibility. BSG addition in baked RBSG focaccia increased the hardness, gumminess, and chewiness by 10%, 9%, and 12%, respectively. BBSG cookies had a 20% increase in fracturability. A positive correlation was found between the rheological metrics of the dough and the textural parameters of BBSG-added cookies. PCA analysis revealed that complex viscosity, G', G″, and cohesiveness separated BBSG focaccia from RBSG focaccia and the control. Therefore, the rheological properties of BSG dough will have industrial relevance for 3D-printed customized food products with fiber. Adding RBSG and BBSG to selected foods will increase the up-cycling potential by combining techno-functional properties.