Relation between structural, mechanical and sensory properties of gluten-free bread as affected by modified dietary fibers

Rice starch, millet flour supplemented with algal biomass for 3D food printing

3D printing has facilitated food production customization, yet there is a lack of exploration into gluten-free cereal materials within this domain. This study investigates the utilization of millet-based 3D printing to produce fortified products incorporating Azolla filliculoides (AF) microalgae. AF contains essential nutrients like carbohydrates, lipids, dietary fiber, and amino acids emphasizing its nutritional significance. Experimental assessments were conducted on dough formulations containing pearl millet flour fortified with AF to standardise rheological and textural characteristics, ensuring precision in 3D printing. Optimal results were observed in formulations with 15 % microalgae incorporation (AF-15 %). Regarding rheology, AF-25 % and AF-15 % formulations exhibited shear-thinning behaviour, with enhanced pseudoplasticity. The texture of 3D printing formulations reflected increased firmness with higher algal biomass, attributed to increased protein and carbohydrate content. Moreover, printing efficiency for gluten-free blends exhibited variability, with occasional errors and increased viscosity in AF-15 % formulations, while AF-25 % formulations proved impractical for printing due to reduced cohesiveness. Color assessments indicated increased pigment saturation with increased algal biomass. Further, mineral analysis demonstrated a significant elevation in the mineral content of the 3D printed products. This affirms the positive impact of Azolla biomass on nutritional and rheological properties in gluten-free 3D printed products.

Influence of microwave processing on nutritional, anti-nutritional, antioxidant and sensory characteristics of kachnar powder and supplemented flatbreads

This study examines the impact of microwave processing on Kachnar (Bauhinia variegata) powder and its application in flatbreads. Microwave treatment reduced anti-nutrient levels of alkaloids, phytates, tannins, and saponins by 83-90 %, enhancing safety. Incorporation of microwaved kachnar powder (MwKP) into flatbreads at 2.5-10 % replacement levels improved nutritional profiles, with increases in ash (0.4-0.9 g/100 g), dietary fiber (2-3 g/100 g), protein (8-9 g/100 g), and minerals such as Fe (3-4 mg/100 g), Zn (3.2-3.9 mg/100 g), Na (3-10 mg/100 g), K (378-388 mg/100 g), Ca (30-45 mg/100 g), and Mg (125-145 mg/100 g). Antioxidant activity also increased significantly (p < 0.05) as measured by DPPH, ABTS, FRAP, and total phenolic and flavonoid contents. Sensory evaluation showed a decline in acceptability for MwKP levels ≥7.5 %, though 5 % supplementation was well-received. The findings suggest that microwave processing is an effective method for reducing anti-nutrient content in Kachnar while improving its nutritional and antioxidant properties, making it a viable ingredient for enhancing baked goods.

The Mechanism Underlying the Increase in Bread Hardness in Association with Alterations in Protein and Starch Characteristics During Room-Temperature Storage

Hardness constitutes one of the primary performance indices of bread. However, there is scarce literature regarding the study of the mechanisms of increased hardness in different breads. In this paper, the hardness and retrogradation rates of five popular brands of bread (DaliGarden, Mankattan, MianLunSi, TOLY, and ZhengMao) in China during storage at room temperature were determined, and the mechanism of increased hardness was revealed by the results in terms of Fourier transform infrared spectroscopy (FTIR), disulfide bonds, 13C solid-state nuclear magnetic resonance (NMR), X-ray diffraction, and differential scanning calorimetry (DSC). The results showed that the sequence for the degree of hardness increase among the five bread brands was DaliGarden > TOLY >Mankattan > MianLunSi > ZhengMao. The bread hardness was likely associated with the gliadin content; the more gliadin, the higher the hardness of the bread. All bread hardness values underwent a rapid increase during storage at room temperature. The hardness level of the bread preferred by Chinese individuals was approximately 105 g, and the hardness of the TOLY bread underwent relatively minor changes during storage at room temperature. The disulfide bond content of all breads apart from Mankattan decreased during storage at room temperature. The increase in the hardness of the bread was attributed to the ordered configuration of the amylopectin structures resulting from water evaporation. The results given in this paper offer a practical hardness index to control the quality of bread. This study is expected to contribute to better quality control and optimization in bread production, enhancing consumers' satisfaction and extending products' shelf lives.

Advancements in modifying insoluble dietary fiber: Exploring the microstructure, physicochemical properties, biological activity, and applications in food industry-A review

Recent research has primarily focused on strategies for modifying insoluble dietary fiber (IDF) to enhance its performance and functionality. IDF is obtained from various inexpensive sources and can be manipulated to alter its biological effects, making it possible to revolutionize food processing and nutrition. In this review, multiple IDF modification techniques are thoroughly examined and discussed, with particular emphasis on the resulting changes in the physicochemical properties, biological activities, and microstructure of the fiber. An extensive overview of the practical applications of modified IDF in food processing is provided. Our study aims to raise awareness about the vast possibilities presented by modified IDF and encourage further exploration and utilization of this field in the realm of food production.

A review on the hydration properties of dietary fibers derived from food waste and their interactions with other ingredients: opportunities and challenges for their application in the food industry

Dietary fiber (DF) significantly affects the quality attributes of food matrices. Depending on its chemical composition, molecular structure, and degree of hydration, the behavior of DF may differ. Numerous reports confirm that incorporating DF derived from food waste into food products has significant effects on textural, sensory, rheological, and antimicrobial properties. Additionally, the characteristics of DF, modification techniques (chemical, enzymatic, mechanical, thermal), and processing conditions (temperature, pH, ionic strength), as well as the presence of other components, can profoundly affect the functionalities of DF. This review aims to describe the interactions between DF and water, focusing on the effects of free water, freezing-bound water, and unfreezing-bound water on the hydration capacity of both soluble and insoluble DF. The review also explores how the structural, functional, and environmental properties of DF contribute to its hydration capacity. It becomes evident that the interactions between DF and water, and their effects on the rheological properties of food matrices, are complex and multifaceted subjects, offering both opportunities and challenges for further exploration. Utilizing DF extracted from food waste exhibits promise as a sustainable and viable strategy for the food industry to create nutritious and high-value-added products, while concurrently reducing reliance on primary virgin resources.

Citrus peel powder alters the rheological properties and 3D printing performance of potato starch gel

Owing to the growing interest in sustainable resource utilization, the current study explores the potential replacement of pectin with citrus peel powder (CP) in starch-based 3D food printing ink formulations. The effect of different concentrations of pectin (1 %, 2 %, 3 %) and CP (1 %, 2 %, 3 %) on the printing fidelity, microstructure, rheological and textural properties of potato starch gel were investigated. The results showed that the 3D printing performance of CP-added inks was higher than that of pectin-added inks at all tested concentrations. The storage modulus of CP-added ink was higher than that of pectin-added ink proving higher printing fidelity of CP-added inks. Additionally, hardness, gumminess, springiness and chewiness of food ink increased with an increase in the concentration of CP while decreased with an increase in concentration of pectin. Interestingly, pectin and CP-added inks displayed similar in vitro digestibility, suggesting an insignificant effect of replacing pectin with CP on in vitro glucose release. Moreover, the antioxidant activity of CP-added ink was higher than pectin-added ink demonstrating the potential applications of CP-added ink in functional ink development. Therefore, this study claims for effective replacement of pectin with CP in starch-based 3D food printing ink formulations as a promising sustainable additive.

Sensory optimization of gluten-free hazelnut omelette and sugar-modified chestnut pudding: A free choice profiling approach for enhanced traditional recipe formulations

The Mediterranean region is distinguished by its gastronomic diversity and a wide variety of indigenous nut crops. In line with changing global food consumers' preferences, a noteworthy aspect is the increasing demand to the use of local varieties in recipe formulation. The aim of the present study was to incorporate the Terra Fria chestnut (Portugal) and Negreta hazelnut from Reus (Spain) in traditional Mediterranean recipes. The sensory, technofunctional, nutritional, and shelf-life characterization were investigated in hazelnut omelette (gluten and gluten-free) and chestnut pudding (sugar and sugar-free) formulations. Results conducted by trained assessors using the free choice profiling (FCP) showed that hazelnut omelette samples were described as "creamy," "smooth," and "handmade." In addition, the texture obtained with the hazelnut omelette gluten-free version showed the softest textural profile analysis attributes, with lower values for hardness (2.43 ± 0.36 N), adhesiveness (-0.38 ± 0.00 g s) and gumminess (2.12 ± 0.14). Furthermore, the shelf-life studies revealed a more golden color (>14.43 of a* CIELAB coordinate) and a lower moisture content (25.36%-43.59%) in the hazelnut flour formulation, in addition to the enrichment in terms of protein (8.36 g/100 g), fiber, and healthy fats. In the case of chestnut pudding, it was observed that the study parameters did not differ significantly from its sweetened analogue with positive attributes in FCP ("toasted," "fluffy," and "sweet"), positioning it as a viable alternative to sugar in this application. Therefore, both hazelnut flour in hazelnut omelette and oligofructose in chestnut pudding proved to be promising ingredients in the formulation of gluten-free and sugar-free developed products, offering attractive organoleptic and textural characteristics.

X-ray diffraction and its emerging applications in the food industry

X-ray diffraction (XRD) is an analytical technique that has found several applications focusing on the identification of crystal structure, space groups, plane, and orientation, in addition to qualitative and quantitative phase identification, and polymorphism behavior. An XRD diffractogram pattern/Bragg's peak can also provide valuable information that can be used for various food applications. While this review details the fundamental principles of XRD, the types of XRD systems, instrumentation, and the components thereof, the focus is to serve as a structured resource on explored applications of XRD in food, majorly revolving around food quality and safety. While recent studies relevant to the field are highlighted, leads for futuristic prospects are presented. With its unique approach, the XRD analysis can prove to be a rapid, robust, and sensitive nondestructive approach to food quality evaluation. Recent reports indicate its scope for nonconventional applications such as the assessment of 3D printability of foods, ice crystal formation, and screening food adulterants. Studies also highlight its scope to complement or replace conventional food quality testing approaches that involve the usage of chemicals, extensive sample preparation procedures, derivatization steps and demand long testing times.

Effects of steam explosion-modified rice bran dietary fiber on volatile flavor compounds retention and release of red date-flavored naan (ethnic specialty food of Xinjiang) during storage

This study explored the effects of steam explosion-modified rice bran dietary fiber (S-RBDF) on red date-flavored naan quality and flavor characteristics. The results revealed that the rheological properties of the dough were improved with the incremental addition of S-RBDF (0-5%). The microstructure revealed that adding an appropriate amount of S-RBDF (1-5%) enabled more starch granules to be embedded in the dough network. Notably, the addition of 5% S-RBDF resulted in naan with an optimum specific volume and texture, which consumers preferred. Additionally, gas chromatography-mass spectrometry analysis showed that adding S-RBDF to naan contributed to the retention and sustained release of pleasant volatile compounds (e.g. red date flavor, etc.), while inhibiting the development of unpleasant volatile compounds by delaying the oxidation and decomposition of lipids and preserving the antioxidant phenolic compounds, thus contributing to flavor maintenance of naan during storage. Overall, these results provided a foundation for developing high-quality flavored naan.

Relationship between microstructure formation and in vitro starch digestibility in baked gluten-starch matrices

Increased prevalence of diabetes prompts the development of foods with reduced starch digestibility. This study analyzed the impact of adding soluble dietary fiber (inulin-IN; polydextrose-PD) to baked gluten-starch matrices (7.5-13%) on microstructure formation and in vitro starch digestibility. IN and PD enhanced water-holding capacity, the hardness of baked matrices, and lowered water activity in the formulated matrices, potentially explaining the reduced starch gelatinization degree as IN or PD concentration increased. A maximum gelatinization decrease (26%) occurred in formulations with 13% IN. Micro-CT analysis showed a reduction in total and open porosity, which, along with the lower gelatinization degree, may account for the reduced in vitro starch digestibility. Samples with 13% IN exhibited a significantly lower rapidly available glucose fraction (8.56 g/100 g) and higher unavailable glucose fraction (87.76 g/100 g) compared to the control (34.85 g/100 g and 47.59 g/100 g, respectively). These findings suggest the potential for developing healthier, starch-rich baked foods with a reduced glycemic impact.

Rhubarb powder: Potential uses as a functional bread ingredient

As a traditional staple food, bread lacks several nutrients such as fiber and minerals. In this study, the possibilities of using rhubarb powder to enrich wheat bread were investigated. Rhubarb powder was replaced with wheat flour at the ratios of 0%, 4%, 8%, and 12%. In order to reveal effects of rhubarb powder on quality properties of bread, color, moisture, total protein, fat content, antioxidant activity, textural, and sensory analysis were conducted. As the rhubarb powder ratio increased, the fiber (10.60 ± 0.55), ash (4.34 ± 0.13), and fat content (2.17 ± 0.55) of bread samples increased significantly (p < 0.05). Antioxidant activity (19.61% ± 0.53%) and total phenolic contents (916.38 ± 2.69) of bread samples also increased significantly (p < 0.05). The colors of the enriched breads were relatively dark. The breads containing 12% rhubarb powder had the highest ash content (4.34 ± 0.13). The samples containing 4% rhubarb powder took the highest sensory scores from the sensory panel in terms of odor, flavor, and overall impression. However, as the ratio of rhubarb powder increased, the sensory values of bread samples decreased. According to the results of this study, rhubarb powder could be used up to 4% to produce acceptable breads in terms of sensory properties with improved nutritional quality.

Gluten-free Nan-e-Fasaee: Formulation optimization on the basis of quinoa flour and inulin

Diversification of gluten-free (GF) bakery products is considerably important, as those who suffer from gluten intolerance should follow a GF diet their whole life. Regarding this study, it was aimed at optimizing the formulation of a quinoa-based GF traditional bakery product, i.e. Nan-e-Fasaee using inulin as a bifunctional agent (both a prebiotic compound and a structure-forming agent). Otherwise, its potential role as a fat and sugar replacer was also assessed. For this purpose, short (S)- and long (L)-chain inulin were used as sugar and fat replacers, respectively, at 0%-50% w/w in quinoa flour (QF)-based GF Nan-e-Fasaee and optimization was done based on rheological, textural, and sensory analysis. Results indicated that QF diet provided the batter with the dominance of elastic modulus and increased hardness (i.e. 5170.0 ± 22.50 g in the presence of QF compared to 1477.0 ± 20.81 g in wheat-based ones). Inulin inclusion reduced the hardness, as the lowest was observed at S-inulin substitution levels of 40% and 50% w/w, with values equal to 2422.0 ± 20.81 and 2431.0 ± 35.57 g, respectively (the most similar ones to control sample). The interference of S-inulin with the non-gelatinized starch structure is supposed to decrease the hardness. The highest score in texture was also perceived at F6 and F13, with values equal to 8.00 ± 0.10 and 7.97 ± 0.05, respectively. Using S- and L-inulin in combination is found to improve the textural characteristics due to preventing the competitive role of sugar in water absorption in formulations containing L-inulin. Regarding optimization of quinoa-based GF Nan-e-Fasaee with reduced sugar and fat levels using inulin, it is found to be feasible.

Effect of Adding Fermented Proso Millet Bran Dietary Fiber on Micro-Structural, Physicochemical, and Digestive Properties of Gluten-Free Proso Millet-Based Dough and Cake

The increasing demand for functional foods has pushed the food industry to produce fiber-enriched products. In this study, rheological, microstructural, physicochemical, and functional characteristics were investigated for whole proso millet dough and cake, fortified with fermented proso millet bran dietary fiber flour (F-DF). Results showed that proso millet flour is less absorbent and stable than the control group. Adding proso millet flour and F-DF reduced the elasticity of the dough and increased its hardness, but had no significant effect on viscosity, cohesion, and resilience. The microstructure analysis exhibited an unformed continuous network formation in proso millet dough. Analyses suggested that proso millet flour combined with the fermented dietary fiber group had significantly higher total phenol content (0.46 GAE mg/g), DPPH• scavenging activity (66.84%), and ABTS•+ scavenging activity (87.01%) than did the other group. In addition, F-DF led to a significant reduction in the predicted released glucose contents of reformulated cakes. In summary, cakes prepared with the involvement of whole proso millet flour and F-DF exhibited less adverse sensory impact and possessed the potential to decrease postprandial blood glucose levels resulting purely from cake consumption.

Quality Assessment and Ripeness Prediction of Table Grapes Using Visible-Near-Infrared Spectroscopy

Ripeness significantly affects the commercial values and sales of fruits. In order to monitor the change of grapes' quality parameters during ripening, a rapid and nondestructive method of visible-near-infrared spectral (Vis-NIR) technology was utilized in this study. Firstly, the physicochemical properties of grapes at four different ripening stages were explored. Data evidenced increasing color in redness/greenness (a*) and Chroma (C*) and soluble solids (SSC) content and decreasing values in color of lightness (L*), yellowness/blueness (b*) and Hue angle (h*), hardness, and total acid (TA) content as ripening advanced. Based on these results, spectral prediction models for SSC and TA in grapes were established. Effective wavelengths were selected by the competitive adaptive weighting algorithm (CARS), and six common preprocessing methods were applied to pretreat the spectra data. Partial least squares regression (PLSR) was applied to establish models on the basis of effective wavelengths and full spectra. The predictive PLSR models built with full spectra data and 1st derivative preprocessing provided the best values of performance parameters for both SSC and TA. For SSC, the model showed the coefficients of determination for calibration (RCal2) and prediction (RPre2) set of 0.97 and 0.93, respectively, the root mean square error for calibration set (RMSEC) and prediction set (RMSEP) of 0.62 and 1.27, respectively; and the RPD equal to 4.09. As for TA, the optimum values of RCal2, RPre2, RMSEC, RMSEP and RPD were 0.97, 0.94, 0.88, 1.96 and 4.55, respectively. The results indicated that Vis-NIR spectroscopy is an effective tool for the rapid and non-destructive detection of SSC and TA in grapes.

Effects of Incorporating Alkaline Hydrogen Peroxide Treated Sugarcane Fibre on The Physical Properties and Glycemic Potency of White Bread

The consumption of dietary fibres can affect glycemic power and control diabetes. Sugarcane fibre (SCF) is known as insoluble dietary fibre, the properties of which can be affected by physical, chemical, and enzymatic treatments. In this study, alkaline hydrogen peroxide (AHP) treatments were conducted over time (0.5, 1, 3, and 5 h) at 12.6% (w/v) SCF and the effects on the physicochemical and structural properties of the SCF were evaluated. After making dough and bread with the SCF, with and without AHP treatments, the glycemic responses of the bread samples were evaluated. Shorter durations of AHP treatment (0.5 and 1 h) reduced lignin effectively (37.3 and 40.4%, respectively), whereas AHP treatment at 1 and 3 h duration was more effective in increasing particle sizes (50.9 and 50.1 μm, respectively). The sugar binding capacity, water holding capacity (from 2.98 to 3.86 g water/g SCF), and oil holding capacity (from 2.47 to 3.66 g oil/g SCF) increased in all AHP samples. Results from Fourier-transform infrared spectroscopy (FTIR) confirmed the polymorphism transition of cellulose (cellulose I to cellulose II). The morphology of SCF detected under scanning electron microscopy (SEM) indicated the conversion of the surface to a more porous, rough structure due to the AHP treatment. Adding SCF decreased dough extensibility but increased bread hardness and chewiness. All SCF-incorporated bread samples have reduced glycemic response. Incorporation of 1, 3, and 5 h AHP-treated SCF was effective in reducing the glycemic potency than 0.5 h AHP-treated SCF, but not significantly different from the untreated SCF. Overall, this study aims to valorize biomass as AHP is commonly applied to bagasse to produce value-added chemicals and fuels.

Development and Optimization of Black Rice (Oryza sativa L.) Sourdough Fermented by Levilactobacillus brevis LUC 247 for Physicochemical Characteristics and Antioxidant Capacity

This study used Levilactobacillus brevis LUC 247 to ferment black rice sourdough, made into Type III black rice sourdough powder to produce black rice sourdough bread. The composition analysis, antioxidant capacity, and storage stability of the black rice sourdough bread with different proportions of black rice powder (0–60%) and fermented for different lengths of time (0–48 h) were discussed. The results showed that the black rice sourdough had the maximum lactic acid bacteria count (9 Log CFU/g) during 12 to 36 h of fermentation. The titratable acid, lactic acid, and acetic acid yields increased with the fermentation time and the proportion of black rice powder. The total anthocyanin content and antioxidant capacity increased with the fermentation time. The hardness and chewiness of the black rice sourdough bread were positively correlated with the black rice sourdough powder content and increased with storage time. In addition, the growth of fungi was significantly slowed as the additional level of black rice sourdough powder increased.

Elm (Ulmus pumila L.) bark flour as a gluten substitute in gluten-free whole foxtail millet bread

Elm bark (Ulmus pumila L.) flour is a nutritious and sustainable edible material for developing the macromolecular network in the food matrix. In this study, the effects of Elm bark flour and water addition on technological and sensory characteristics of gluten-free whole foxtail millet bread were investigated. Structural analysis methods such as SEM, X-ray diffraction, and FTIR were used to supplement the rheological properties and baking quality. Results showed that Elm bark flour improved gelatinization characteristics and rheological properties (tanδ < 1) of gluten-free dough. Moreover, the porous and network structure of gluten-free bread was observed by image analysis and further confirmed by Fourier transform infrared spectroscopy and X-Ray diffraction, endowing higher specific volume (1.98 ± 0.13 cm3/g), and a decrease hardness from 97.43 to 11.56 N. Additionally, with the incorporation of Elm bark flour-water combination, specific volume (2.15 ± 0.09 cm3/g) and hardness (6.83 ± 0.50 N) were further optimized. Combined with the results of rheological properties and bread structure, Elm bark flour at 15% ratio and water addition at 120% level exhibited the most potent improvement of gluten-free bread. These results might contribute to the potential utilization of Elm bark flour as the sustainable resource in gluten-free products.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05670-x.

The use of time domain 1 H NMR to study proton dynamics in starch-rich foods: A review

Starch is a major contributor to the carbohydrate portion of our diet. When it is present with water, it undergoes several transformations during heating and/or cooling making it an essential structure-forming component in starch-rich food systems (e.g., bread and cake). Time domain proton nuclear magnetic resonance (TD ¹ H NMR) is a useful technique to study starch-water interactions by evaluation of molecular mobility and water distribution. The data obtained correspond to changes in starch structure and the state of water during or resulting from processing. When this technique was first applied to starch(-rich) foods, significant challenges were encountered during data interpretation of complex food systems (e.g., cake or biscuit) due to the presence of multiple constituents (proteins, carbohydrates, lipids, etc.). This article discusses the principles of TD ¹ H NMR and the tools applied that improved characterization and interpretation of TD NMR data. More in particular, the major differences in proton distribution of various dough and cooked/baked food systems are examined. The application of variable-temperature TD ¹ H NMR is also discussed as it demonstrates exceptional ability to elucidate the molecular dynamics of starch transitions (e.g., gelatinization, gelation) in dough/batter systems during heating/cooling. In conclusion, TD NMR is considered a valuable tool to understand the behavior of starch and water that relate to the characteristics and/or quality of starchy food products. Such insights are crucial for food product optimization and development in response to the needs of the food industry.

Development of a Novel Rice-Based Snack Enriched with Chicory Root: Physicochemical and Sensory Properties

A novel rice-based snack enriched with chicory root flour (CRF) was developed by twin-screw extrusion. Chicory (Cichorium intybus L.) is one of the promising medicinal plants for the development of innovative food and may be considered a functional food ingredient. Central composite design (CCD) was employed to generate snack formulations by varying feed moisture (M, 16.3–22.5%), screw speed (SS, 500–900 rpm) and CRF content (20–40%). The optimization according to artificial neural network modeling and a genetic algorithm was applied to define optimal process conditions (17.6% moisture, 820 rpm and 24.1% of CRF) for obtaining the product with the highest expansion (3.34), crispiness (3.22 × 10−3), volume (2040 m3), degree of gelatinization (69.70%) and good color properties. Bulk density (110.33 g/L), density (250 kg/m3), and hardness (98.74 N) resulted in low values for the optimal sample. The descriptive sensory analysis evaluated low hardness and bitterness, with high crispiness for the optimal extrudate. This study points to the possibility of a novel chicory enriched extrudate production with desirable physicochemical and sensory properties.

Gluten-free bakery products: Ingredients and processes

There is an increasing demand for gluten-free products around the world because certain groups of people, which have increased in the last decades, need to eliminate gluten from their diet. A growing number of people consider gluten-free products to be healthier. However, making gluten-free products such as bread is a technological challenge due to the important role of the gluten network in their development. However, other products, such as cakes and cookies usually made with wheat flour, can easily be made with gluten-free starches or flours since gluten does not play an essential role in their production. To replace wheat flour in these elaborations it is necessary to resort to gluten-free starches and/or flours and to gluten substitutes. Additionally, it can be convenient to incorporate other ingredients such as proteins, fibers, sugars or oils, as well as to modify their quantities in wheat flour formulations. Regarding gluten-free flours, it will also be necessary to know the parameters that influence their functionality in order to obtain regular products. These problems have originated a lower availability of gluten-free products which have a worse texture and are less tasty and more expensive than their homologues with gluten. These problems have been partially solved thanks to research on these types of products, their ingredients and their production methods. In recent years, studies about the nutritional improvement of these products have increased. This chapter delves into the main ingredients used in the production of gluten-free products, the processes for making gluten-free breads, cakes and cookies, and the nutritional quality of these products.

Structural, Physicochemical, and Functional Properties of Wheat Bran Insoluble Dietary Fiber Modified With Probiotic Fermentation

Insoluble dietary fiber (IDF) were isolated from wheat bran (WB) after microbial fermentation with single or mixed strain [Lactobacillus plantarum, Lactobacillus acidophilus, Bacillus subtilis or mixed lactic acid bacteria (L. plantarum and L. acidophilus with ration of 1:1)]. Structure, physicochemical, functional properties, and antioxidant activity of the wheat bran insoluble dietary fiber (W-IDF) modified by fermentation were studied. Fourier transformed infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM) analysis suggested the successful modification of W-IDF. After fermentation with L. plantarum and mixed lactic acid bacteria, the water retention capacity (WRC), oil retention capacity (ORC), and water swelling capacity (WSC) of W-IDF were improved. The sodium cholate adsorption capacity (SCAC), and cation exchange capacity (CEC) of W-IDF modified with L. acidophilus fermentation were significantly increased. Although the cholesterol adsorption capacity (CAC) of W-IDF decreased after modification with probiotic fermentation, nitrite ion adsorption capacity (NIAC), and total phenolic content (TPC) were enhanced. Additionally, W-IDF modified by fermentation with B. subtilis or mixed lactic acid bacteria exhibited superior antioxidant capacity verified by DPPH, ABTS and total reducing power assays. Results manifested that microbial fermentation is a promising methods to modify the W-IDF to provide high-quality functional IDF for food processing and human health management.

Dietary fiber in bakery products: Source, processing, and function

Bakery products are prevalently consumed foods in the world, and they have been regarded as convenient dietary vehicles for delivering nutritive ingredients into people's diet, of which, dietary fiber (DF) is one of the most popular items. The food industry attempts to produce fiber-enriched bakery products with both increasing nutritional value and appealing palatability. As many new sources of DFs become available, and consumers are moving towards healthier diets, studies of using these DFs as functional ingredients in baked goods are becoming vast. Besides, the nutrition value of DF is commonly accepted, and many investigations have also revealed the health benefits of fiber-enriched bakery products. Thus, this chapter presents an overview of (1) trends in supplementation of DF from various sources, (2) impact of DF on dough processing, quality and physiological functionality of bakery products, and (3) technologies used to improve the compatibility of DF in bakery products.

Insoluble Dietary Fibers From By-Products of Edible Fungi Industry: Basic Structure, Physicochemical Properties, and Their Effects on Energy Intake

With the rapid development of the edible fungi industry in the world, especially in China, the resource utilization of edible fungi by-products has become an urgent problem for the industry's sustainable development. The waste residue of edible fungi after polysaccharide extraction by water accounts for a large proportion, which contains a large amount of water-insoluble dietary fiber (IDF). At present, the extracted residue is generally treated as fertilizer or solid waste, which not only pollutes the environment, but wastes resources too. In order to develop these by-products, expand their potential utilization in the food industry, the structure characterization, physicochemical properties, and the influence of IDF on dietary energy intake were studied. The IDF from the residues of polysaccharides extracted from four edible fungi was extracted using the Association of Official Analytical Chemists (AOAC) method. The results showed that IDF in the four kinds of edible fungi residues was similar in composition but different in texture. Cellulose and hemicellulose are the main IDF extracted from four kinds of edible fungi. Among them, Hericium erinaceus is the softest without obvious granular texture, following Lentinus edodes, while Ganoderma lucidum and Grifola frondosa have a relatively hard texture. The yield of four kinds of IDF from high to low came from Ganoderma lucidum, Hericium erinaceus, Lentinus edodes, and Grifola frondosa. Fourier transform IR (FTIR) and X-ray diffraction (XRD) spectra showed that the four IDFs had similar functional groups and all of them contained a large amount of cellulose. Physical and chemical analysis showed that all the four IDFs had certain water holding capacity, water binding capacity, and oil holding capacity. In-vitro digestion experiments showed that the four IDFs could inhibit the digestion of starch and fat to a certain extent. By-products of edible fungi are an ideal material for the recovery of IDFs, which have the potential to be processed into functional food materials due to their physicochemical properties and physiological functions.

Effect of Microwave Heat Processing on Nutritional Indices, Antinutrients, and Sensory Attributes of Potato Powder-Supplemented Flatbread

This study aims at evaluating nutritional, toxicological, and sensory attributes of microwave heat-treated potato powder-supplemented unleavened flatbread. Straight-grade wheat flour (SGF) was substituted with potato powder at the rate of 2.5–10% d.w. A comparison was made for nutritional, antinutrient, and organoleptic attributes of microwave heat-treated potato powder and SGF—potato powder composite flour-based flatbreads. The results suggest processed potato powder supplementation in SGF to significantly ( $p<0.05$ ) improve ash (0.48 to 0.63 g/100 g), dietary fiber (2.15 to 2.61 g/100 g), and protein (8.33 to 9.91 g/100 g) contents of composite chapatis. Likewise, significant ( $p<0.05$ ) improvement in the concentration of microelements and trace elements was observed including Ca, Na, K, Fe, and Zn contents, which were increased from 29.7 to 33.5 mg/100 g, 2.8 to 6.3 mg/100 g, 376 to 466 mg/100 g, 3.1 to 3.4 mg/100 g, and 3.17 to 3.25 mg/100 g, respectively. Microwave heating of potato powder was observed to reduce the load of alkaloids, oxalates, tannins, and phytates of the raw potato powder at the rate of 76%, 80%, 84%, and 82%, respectively, thus anticipating a promising response to minimize toxicant load in supplemented flatbread. Supplementing potato powder in SGF elucidated significant ( $p<0.05$ ) improvement in color values, i.e., a∗ (1.89–2.32) and b∗ (10.95–13.22), and increased product hardness from 3.17 to 7.9 N. The study concludes that microwave heat-treated potato powder yield improved nutritional and safety concerns of the consumers when used alone or as a supplement for developing composite flours based on value-added products.

A review of extrusion-modified underutilized cereal flour: chemical composition, functionality, and its modulation on starchy food quality

Compared with three major cereals, underutilized cereals (UCs) are those with less use but having abundant bioactive components and better functionalities after proper processing. As a productive and energy-efficient technology, extrusion has been used for UC modification to improve its technological and nutritional quality. Extrusion could induce structural and quantitative changes in chemical components of UC flour, the degree of which is affected by extrusion intensity. Based on the predominant component (starch), functionalities of extruded underutilized cereal flour (EUCF) and potential mechanisms are reviewed. Considering bioactive compounds, it also summarizes the physiological functions of EUCF. EUCF incorporation could modulate the dough rheological behavior and starchy foods quality. Controlling extrusion intensity or incorporation level of EUCF is vital to achieve sensory-appealing and nutritious products. This paper gives comprehensive information of EUCF to promote its utilization in novel staple foods.

Delving into the Role of Dietary Fiber in Gluten-Free Bread Formulations: Integrating Fundamental Rheological, Technological, Sensory, and Nutritional Aspects

The evidenced relevance of dietary fibers (DF) as functional ingredients shifted the research focus towards their incorporation into gluten-free (GF) bread, aiming to attain the DF contents required for the manifestation of health benefits. Numerous studies addressing the inclusion of DF from diverse sources rendered useful information regarding the role of DF in GF batter’s rheological properties, as well as the end product’s technological and nutritional qualities. The presented comprehensive review aspires to provide insight into the changes in fiber-enriched GF batter’s fundamental rheological properties, and technological, sensory, and nutritional GF bread quality from the insoluble and soluble DF (IDF and SDF) perspective. Different mechanisms for understanding IDF and SDF action on GF batter and bread were discussed. In general, IDF and SDF can enhance, but also diminish, the properties of GF batter and bread, depending on their addition level and the presence of available water in the GF system. However, it was seen that SDF addition provides a more homogenous GF batter structure, leading to bread with higher volumes and softer crumb, compared to IDF. The sensory properties of fiber-enriched GF breads were acceptable in most cases when the inclusion level was up to 7 g/100 g, regardless of the fiber type, enabling the labeling of the bread as a source of fiber.

Nutritional, physical and sensory characteristics of gluten-free biscuits incorporated with a novel resistant starch ingredient

Gluten-free (GF) biscuits were prepared by replacing part of a GF flour mix (GFM) with 0, 15, 30 and 45 g/100 g (total flour) with a novel resistant starch-rich ingredient obtained from annealed white sorghum starch (RSWS). The chemical composition, physical characteristics, in vitro starch digestion and sensory evaluation of biscuits were considered. The chemical composition of samples was influenced by the addition of the RSWS. The highest total dietary fibre and RS contents (p < 0.05) were measured in 45-RSWS biscuits. The starch hydrolysis index values decreased when the level of RSWS increased in the composite. With regard to quality parameters, the use of RSWS influenced the hardness of the biscuits, and the highest value obtained for 45-RSWS. Some of the selected sensory attributes, along with the overall acceptability score, were negatively influenced by the RSWS addition, even if all remained above the limit of acceptability. The use of RSWS in GF biscuit formulation can contribute towards the creation of food products likely having slowly digestible starch properties, and this can be achieved without drastically compromising on the quality and sensory attributes.

Current Status in the Utilization of Biobased Polymers for 3D Printing Process: A Systematic Review of the Materials, Processes, and Challenges

Three-dimensional (3D) printing is a revolutionary additive manufacturing technique that allows rapid prototyping of objects with intricate architectures. This Review covers the recent state-of-the-art of biopolymers (protein and carbohydrate-based materials) application in pharmaceutical, bioengineering, and food printing and main reinforcement approaches of biomacromolecular structure for the development of 3D constructs. Some perspectives and main important limitations with the biomaterials utilization for advanced 3D printing procedures are also provided. Because of the improved the ink's flow behavior and enhance the mechanical strength of resulting printed architectures, biopolymers are the most used materials for 3D printing applications. Biobased polymers by taking advantage of modifying the ink viscosity could improve the resolution of deposited layers, printing precision, and consequently, develop well-defined geometries. In this regard, the rheological properties of printable biopolymeric-based inks and factors affecting ink flow behavior related to structural properties of printed constructs are discussed. On the basis of successful applications of biopolymers in 3D printing, it is suggested that other biomacromolecules and nanoparticles combined with the matrix can be introduced into the ink dispersions to enhance the multifunctionality of 3D structures. Furthermore, tuning the biopolymer's structural properties offers the most common and essential approach to attain the printed architectures with precisely tailored geometry. We finish the Review by giving a viewpoint of the upcoming 3D printing process and recognize some of the existing bottlenecks facing the blossoming 3D pharmaceutical, bioengineering, and food printing applications.

Influence of Replacement Part of Starch with Inulin on the Rheological Properties of Pastes and Gels Based on Potato Starch

The objective of the present study was to determine the influence of replacement part of starch with inulin on the rheological characteristics of pastes and gels obtained on the basis of potato starch. Replacement of the starch by inulin varied from 0 to 40%. Flow curves for pastes and gels were determined, and the viscoelastic properties were characterized using dynamic tests and creep and recovery tests. It was determined that the replacement of part of potato starch with inulin significantly modifies rheological properties of starch pastes and gels, weakening their structure. With the increasing amount of inulin, an increase of viscous properties was becoming more apparent. Moreover, an irregular influence of inulin addition on the parameters of rheological characteristics was determined. Initially, the differences were minor, and the differences at the lowest addition were typically statistically insignificant, followed by strong increase with local restrictions to structural weakening.

Comparison of structural, functional and in vitro digestion properties of bread incorporated with grapefruit peel soluble dietary fibers prepared by three microwave-assisted modifications

In our previous study, three kinds of grapefruit peel soluble dietary fibers (SDFs) were prepared by microwave-assisted modifications, including microwave-sodium hydroxide treatment SDF (MST-SDF), microwave-enzymatic treatment SDF (MET-SDF) and microwave-ultrasonic treatment SDF (MUT-SDF). The present study aimed to investigate the structural, functional and in vitro digestion properties of three kinds of bread incorporated with SDFs, named MST-SDF bread (SB), MET-SDF bread (EB), and MUT-SDF bread (UB). Scanning electron microscopy, X-ray diffraction, differential scanning calorimetry and texture profile analysis were used to determine the structural properties. In comparison with the SB and EB, the UB showed an ideal hardness and internal structure, and also significant improvement of the thermal stability. Meanwhile, the UB exhibited the highest overall acceptability in the sensory evaluation. In addition, the water holding capacity (WHC), cholesterol adsorption capacity (CAC) and nitrite ion adsorption capacity (NIAC) of UB were superior to those of the other two samples. Moreover, the in vitro digestive glucose release rates of breads were all significantly reduced by the addition of SDFs, especially that of UB. In summary, the present study showed that UB presented the best performance in terms of structural, functional and in vitro digestion properties, implying that MUT-SDF could be utilized in bread with high quality and low glucose release rate, and developed as a potential ingredient of functional food.

Potential of grape byproducts as functional ingredients in baked goods and pasta

Wine making industry generates high quantities of valuable byproducts that can be used to enhance foods in order to diminish the environmental impact and to obtain more economic benefits. Grape byproducts are rich in phenolic compounds and dietary fiber, which make them suitable to improve the nutritional value of bakery, pastry, and pasta products. The viscoelastic behavior of dough and the textural and the sensory characteristics of baked goods and pasta containing grape byproducts depend on the addition level and particle size. Thus, an optimal dose of a finer grape byproducts flour must be found in order to minimize the negative effects such as low loaf volume and undesirable sensory and textural characteristics they may have on the final product quality. In the same time, an enrichment of the nutritional and functional value of the product by increasing the fiber and antioxidant compounds contents is desired. The aim of this review was to summarize the effects of the chemical components of grape byproducts on the nutritional, functional, rheological, textural, physical, and sensory characteristics of the baked goods and pasta. Further researches about the impact of foods enriched with grape byproducts on the human health, about molecular interactions between components, and about the effects of grape pomace compounds on the shelf life of baked goods and pasta are recommended.

Properties of Peanut (KAC431) Protein Hydrolysates and Their Impact on the Quality of Gluten-Free Rice Bread

Protein hydrolysates (PH) with a degree of hydrolysis (DH) of 5%, 10%, and 13% from two varieties of peanut were prepared using two commercial enzymes, Alcalase and Flavourzyme. The content of essential amino acids (30,290 mg/100 g) and hydrophobic amino acids (34,067 mg/100 g) of the peanut variety Kalasin 2 (KAC431) protein was higher than that of a common variety, Kalasin 1 (KAC1) (p < 0.05). The protein molecular weight distributions of the two varieties of peanut detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) were similar, ranging from 15 to 75 kDa, with a major protein band at 50–75 kDa. The antioxidant and functional properties of derived PHs were influenced by DH. Although the foaming ability of protein was improved by DH5%, it was obviously decreased upon increasing DH further. The best emulsifying properties were observed in PH with DH5% (p < 0.05). The incorporation of PH with a small DH, especially when produced using Flavourzyme, had a highly positive impact on the specific volume and relative elasticity of gluten-free bread. The effect of PHs on bread quality was highly correlated with their functional properties. This study suggests that partially enzymatically modified proteins are suitable for incorporation in food products such as bread and other gluten-free products.