Wheat Flour Enriched with Calcium and Inulin: A Study of Hydration and Rheological Properties of Dough

Effect of Freezing Wheat Dough Enriched with Calcium Salts with/without Inulin on Bread Quality

Bread is a popular food that is widely consumed worldwide but has a short shelf life. Besides that, when incorporating prebiotics and calcium, aging mechanisms accelerate, further shortening the shelf-life. The objective of this work was to evaluate the effect of freezing storage on the rheological (loss tangent, tan δ) and thermal (glass transition temperature, Tg) properties of unfrozen dough, the fermentation times (tf), and the baking quality of wheat bread fortified with calcium and inulin. Formulations studied included wheat flour (control-C), flour with 1800 ppm Ca (calcium carbonate-CA, calcium citrate-CI or calcium lactate-LA), and flour with 2400 ppm Ca and 12% inulin (calcium carbonate-CA-In, calcium citrate-CI-In or calcium lactate-LA-In). Doughs were stored at −18 °C for 1, 7, 30 and 60 days. After storage, the rheological (oscillatory rheometry and texture profile analysis) and thermomechanical properties of the thawed doughs were measured. The quality parameters of breads determined consisted of specific volume (Vs), color, moisture, firmness, elasticity, and alveoli size characterization. Dough freezing neither changed viscoelasticity (tan δ) nor decreased hardness and adhesiveness up to the values observed for fresh wheat dough. The Tg of dough with calcium carbonate increased, while for samples with organic calcium salts, it (citrate and lactate) decreased. The tf of thawed dough significantly increased. The Vs of all breads did not change during the first 30 days but decreased after freezing the dough for 60 days (p < 0.05), probably due to the death of the yeasts. Crumb moisture decreased over time, and in all cases crumb C had the highest moisture content, suggesting a dehydration effect of the calcium salt. The firmness of CA, LA and C crumbs were similar and higher than that of CI (p < 0.05), suggesting a destabilizing effect of CI anion on gluten proteins. Inulin contributed to the depreciation of bread quality, mainly at 60 days of dough freezing storage. It can be concluded that during freezing storage, calcium improves the dynamic elasticity of the dough, although under extreme conditions it generates loaves of smaller volume. Principal component analysis (PCA) explained 66.5% of total variance. Principal component 1 (PC1) was associated with dough properties, and accounted for 44.8% of the total variance. In turn, PC2 was mainly related to baking quality parameters (fermentation time, browning index, firmness and springiness of crumbs), and explained 21.7% of the total variance. Fortification with calcium citrate should be recommended for dough freezing, as breads with softer crumbs were obtained under such conditions.

Effect of the Addition of Dried Dandelion Roots (Taraxacum officinale F. H. Wigg.) on Wheat Dough and Bread Properties

Dried and crushed dandelion roots (Taraxacum officinale F. H. Wigg.) (TO) were used as a formulation additive (at the amount of 0, 1, 3, 4, 5, and 6 g 100 g⁻¹ flour) to wheat bread. The farinographic properties of the dough and the physical and chemical properties of the bread were evaluated. It was found that the addition of dried flour caused a significant decrease in water absorption by the flour (1% and higher TO level), an increase in the development time (from 2% to 5% TO addition) and dough stability (3% and 4% TO level), and an increase in dough softening (4% and higher TO level). As the substitution of TO for wheat flour increased, there was a gradual decrease in loaf volume, an increase in specific weight and crumb hardness, and a darkening of the crumb color. The total polyphenol content increased linearly with the percentage increase of dried root additions TO from 0.290 to 0.394 mg GAE g⁻¹ d.m_., which translated into an increase in the antioxidant activity of the bread. It was found that dried crushed roots of Taraxacum officinale can be a recipe additive for wheat bread; however, due to their specific smell and bitter aftertaste, the level of this additive should not exceed 3 g 100 g⁻¹ flour.

Changes in rheology, quality, and staling of white breads enriched with medium-polymerized inulin

The objective of this study was to evaluate the changes that occurred during processing white breads enriched with 5, 7.5, and 10% of medium-polymerized inulin (MPI). Farinographic analysis revealed that enrichment caused the development time and dough stability to increase by up to 69.9% and 62.8%, respectively, when 7.5% of MPI was incorporated into wheat flour. This indicated that the added MPI strengthened the doughs. Conversely, alveographic analysis demonstrated that MPI was harmful to the gluten network. The specific volume and humidity of breads with up to 7.5% MPI were similar to those of the control (MPI-free) bread. During bread storage for 10 days, we noticed that the retrogradation rate increased only for the bread sample with 10% MPI. However, MPI enrichment, regardless of concentration, promoted an increase in the Avrami exponent and affected bread firmness. Bread staling analysis indicated that the moisture difference between crumb and crust was higher for the MPI-enriched breads than for the control. Moreover, we prepared more consistent doughs and fresh breads with MPI contents of up to 7.5%, which presented good quality and were good fiber sources; however, we determined that inulin did not present an anti-staling effect.

Influence of flour type on physico-chemical characteristics during deep frying

The study focuses on understanding the influence of nutrients on frying oil degradation as well as its role in oil uptake by the fried substrate. Raw substrates were prepared taking refined wheat flour (rich in carbohydrate), soy flour (rich in protein) and gram flour (with both in a definite proportion) which were subjected to frying in sunflower oil at 185-200 °C. Analysis of the fried oil, substrate and fried product was carried out. Increase in acid value with respect to the composition of the flour was not significant. Higher rate of oxidation and peroxide value were observed in the oil used for Gram flour snacks, which could be due to significant amounts of sodium and potassium salts. Fried oil with soy flour based snack showed higher total polar material% which could be due to accelerated oxidation. Oil absorption was promoted by starch and gluten and controlled by protein and insoluble fiber. Oil absorbed by refined-wheat flour and soy flour based snack were 30% and 9.33%. Gram flour-based snack absorbed 4.52% oil with superior oil quality comparatively.

Quality and microbial properties of symbiotic bread produced by straight dough and frozen part-baking methods

Symbiotic bread was produced by straight dough and frozen part-baking methods using inulin as a prebiotic (0-7.5% in straight dough method and 5% in frozen part baked bread) and GanedenBC 30 as a probiotic. With addition of inulin, dough water absorption and softening reduced, but dough development time and stability time increased. Inulin prevented excessive moisture loss during bread storage and enhanced crust darkness and crumb firmness while reduced bread volume. Increasing the frozen storage time (up to 56 days) had no effect on bread moisture content, but it reduced volume and increased firmness and crust lightness. Samples produced by straight dough method had acceptable levels of probiotic (7.45, 6.45, and 7.43 log cfu/g, respectively) complying with the WHO recommendation. Frozen storage had no effect on the probiotic content of the samples and it increased to 7.35 log cfu/g (above the minimum recommended level) after re-baking and storage at room temperature. PRACTICAL APPLICATIONS: Symbiotic foods are products that contain both probiotics (useful bacteria) and prebiotics (carbohydrate source for probiotics). Development of symbiotic bread is required to add variety to the existing types of functional breads and satisfy costumers particularly those avoiding dairy products which are traditionally enriched with probiotics. Part-baked bread industry is growing rapidly around the world; however, to remain in the market it requires innovation to satisfy consumers' demand for healthy products. This research can find practical application for ordinary and part-baked bread industry to produce bread with improved health benefits and acceptable quality.

Potential functional bakery products as delivery systems for prebiotics and probiotics health enhancers

Several health benefits have been associated to probiotics and prebiotics, most of these are involved in the regulation of the host's gut microbiome. Their incorporation to diverse food products has been done to develop potential functional foods. In the case of bakery products, their incorporation has been seen to improve several technological parameters such as volume, specific volume, texture along with sensorial parameters such as flavor and aroma. Scientific literature in this topic has been divided in three main research branches: nutrition, physical quality and sensory analyzes, however, studies rarely cover all of them. Due to the harsh thermal stress during baking, sourdough technology along with microencapsulation of probiotics, has been studied as an alternative to enhance its nutritional values and increase cell viability, though in few occasions. The potential functional baked goods have maintained acceptable physical characteristics and sensorial acceptability, while in some cases an improvement is seen due to the effect of probiotics and prebiotics. The results obtained from several studies done, have shown the viability of developing functional bakery products by applying prebiotics or probiotics. This could be used as an encouragement for more research to be done in this topic.

Technological quality of dough and breads from commercial algarroba-wheat flour blends

Algarroba flour is used to supplement lysine-limiting systems such as wheat flour due to its amino acidic composition. The effects of adding up to 30% of this flour to wheat flour (W-A30) on dough characteristics and breadmaking performance were studied. Dough rheology was tested by farinograph, oscillatory rheometry and texture profile analyses. Molecular mobility was evaluated by nuclear magnetic resonance, and thermal properties were analyzed by differential scanning calorimetry and viscoamylograph studies. Besides, different bread quality parameters were evaluated. Incorporation of algarroba flour resulted into increase in water absorption, development time and degree of softening, and decrease in stability of wheat flour, leading to softer, less adhesive and elastic dough, although at intermediate replacement levels cohesiveness improved. At the molecular level, a reduction of water activity and limited proton motion were observed in W-A30 samples, suggesting that protons were highly bound to the dough matrix. Dough samples with algarroba flour showed lower G' and G″ values than the control, although with the formation of a more elastic structure for W-A30. In addition, algarroba flour produced a protective effect on starch granule disruption and interfered with amylose-amylose association during cooling. The specific volume of breads decreased with the increase in algarroba level, W-A30 reaching the highest decrease (15%). Bread crumbs with algarroba flour exhibited higher values of hardness and resilience. The use of algarroba flour resulted in lower quality when compared to the control. However, algarroba flour at 20% level can be added to wheat flour to obtain bakery products of similar technological quality and with improved nutritional components.

Wheat bread enriched with organic calcium salts and inulin. A bread quality study

The objective of this work was to study quality parameters of enriched wheat bread with calcium citrate (Ca3CI2) or lactate (CaLA2) and inulin (In), also to optimize bread formulation. Fermentation time (tf), specific volume (Vs), browning index of crust (BI) and crumb properties (moisture, alveolus, texture) were studied. Generally, tf and Vs decreased with prebiotic increment. Ca3CI2 did not change Vs at equal inulin quantity, whereas with CaLA2 smaller breads were obtained (at 6.5 % In). Moisture of crumbs decreased with an increase in Ca3CI2 (at ≤ 6.5 %); while for CaLA2 was more influenced by the prebiotic. Up to 6.5 % In, the addition of both salts decreased crumb firmness and increased cohesiveness. Using a desirability function, the optimum calcium-prebiotic bread obtained with Ca3CI2 contained 2.40 g/kg Ca and 7.49 % In and with CaLA2 presented 1.33 g/kg Ca and 4.68 % In. Breads of high-quality with higher calcium and prebiotic quantity were able to obtain with Ca3CI2.