Crumb Moisture Content Research Articles

Effect of modified atmosphere packaging on stability of three kinds of bread

The study evaluates effect of ordinary and modified atmosphere N2 and CO2 on bread packaging and changes of selected bread parameters, moisture content (MC) and water activity (Aw), in real storage time. MC has a significant influence on physical properties of bread and Aw characterizes its microbiological stability. Both parameters are functionally dependent. Manometric method was used for measurement of Aw and gravimetric method was used for measurement of MC. Samples of three kinds of bread, gluten-free, Šumava bread, and Bavorský bread, packaged into barrier wrappers, were stored at the room temperature of 20 °C. MC and Aw were measured in real storage time in intervals of three days for all kinds of bread, always in crust and crumb separately. Individual measurements were finished when a mould were discovered in samples. The initial MC of crust was in the range of 21.01–29.26% MC (w.b.) and the final MC in the range of 26.79–33.58% MC (w.b.) in tested breads. MC of crumb was in the range of 34.49–46.58% MC (w.b.) at the beginning and in the range of 32.92–44.21% MC (w.b.) at the end in tested samples. Minimum differences within values of MC showed gluten-free bread during storage time. Values of Aw were in the range of 0.863–0.948 at the beginning and in the range of 0.933–0.958 at the end of measurement in crust, for all samples. Values of Aw were in the range of 0.960–0.961 at the beginning and in the range of 0.952–0.961 at the end of measurement in crumb. Minimum differences within values of Aw showed gluten-free bread again. The highest shelf-life has been achieved in CO2 atmosphere, for all kinds of bread. Mathematical models with ability for MC and Aw prediction in real time of storage were created for Šumava bread.

Effect of the addition of bran fractions on bread properties

High fibre breads were produced adding durum wheat bran fractions of different composition and particle size. Fresh products were characterized for texture, crumb grain, volume, colour, water status (water activity, moisture content, frozen water content, 1H molecular mobility).The addition of bran fractions with different composition resulted in significantly harder samples with lower volumes as compared to the control (STD), while bran fractions with different particle size did not significantly affect the volume and hardness of the samples (comparable to STD).The addition of bran fractions with different composition and particle size resulted in an altered water status, as shown by crumb moisture content (∼43% vs ∼41% in STD), water activity (0.97 vs 0.96 in STD) and frozen water content (∼60–66% vs ∼51% in STD). 1H NMR data showed an altered 1H molecular mobility in bran breads as compared to STD. In particular, an additional 1H T2 population was found in the bran samples. This population has been related to the influence of bran on starch-gluten-water interactions.

Impact of Humidified Baking on Crust and Crumb Properties of Open Bread during Storage

Humidified baking was investigated in the light of producing breads envisaged to have better quality and freshness. Open bread loaves were prepared using the straight dough method where baking was performed with or without humidity at three levels of temperatures of 185, 195 and 205°C, and baking times of 25, 30 and 35 min. Baked breads were evaluated by measuring its crust color and thickness, and bread crumb moisture content and firmness. Humidified baking has no significant effect in enlightening bread crust color (P > 0.05) but significantly reduced the crust thickness (P < 0.001) and increased the initial moisture content (IMC) of bread crumb. The higher IMC of bread crumb led to a higher final moisture content (FMC) of bread during storage and these helped to reduce the firming rate of bread during a 96 h storage especially for the lower baking temperatures and times. Significant differences (P < 0.001) were observed on crust color and thickness, and bread crumb moisture content and firmness as effect of baking temperature and time.

Rheological properties of wheat flour and quality characteristics of pan bread as modified by partial additions of wheat bran or whole grain wheat flour

SummaryThe use of bran and whole grain flour changes dough rheology and causes difficulties in manufacturing bakery products. The aim of this study was to analyse the influence of substituting refined wheat flour (WF) by wheat bran (WB; 5%, 10%, 20%, 30% and 40%) or whole grain wheat flour (WGWF; 10%, 20%, 30%, 40% and 50%) on dough rheological properties and pan bread quality characteristics. The addition of WB and WGWF increased water absorption and resistance to extension and decreased stability, extensibility and peak viscosity. Effects with WB were more pronounced. The presence of WB or WGWF increased crumb moisture content, firmness and hardness and decreased specific volume of pan bread. It is important to set new farinographic and extensographic standards when using WB and WGWF, allowing for a correct correlation between rheology and quality characteristics of bakery products, as the same standards used for WF are not valid.

Optimization of Bread Baking Parameters in Conventional Oven

Optimization of baking parameters in conventional oven was done for cup breads to hasten the bread baking process.The breads were baked at three different baking temperatures of 175 oC, 200 oC and 225 oC at 5 min interval in rangeof 5 min to 30 min at each temperature. The crumb moisture content, crust hardness and colour were determined andthe operating parameters were optimized as: (1) 175 oC and 30 min, (2) 200 oC and 25 min and (3) 225 oC and 20 min

Supplementation of common white bread by coriander leaf powder

Coriander leaves are widely used worldwide as a very common garnish in almost all types of Western, Oriental, and Arabic culinary. It is rich in the beneficial components of antioxidants, trace elements, and essential oils. Bread enriched with coriander leaf powder is therefore likely to have greater acceptability to consumers compared to unfortified bread. In the present study the antioxidant and sensory analyses along with baking and staling characteristics of such breads at supplementation levels of 1.0, 3.0, 5.0, and 7.0%(w/w) on wheat flour have been investigated. Results show that supplementation with coriander leaf powder bettered the crumb moisture content with only a little increase in crumb firmness. A substantial improvement in sensory characteristics was observed with the supplemented breads. A sharp increase in antioxidant content was an important beneficial fortification effect observed in the fortified breads. Coriander leaf content between 3.0 and 5.0% was found to be the optimum supplementation level that offered the best compromise for highest acceptability of the fortified breads.

Use of endoxylanase treated cereal brans for development of dietary fiber enriched cakes

Oat and rice bran were treated with different levels (0, 70 and 700 ppm) of an endoxylanase enzyme and added to cakes on 30% flour weight basis. The water binding and holding capacity of brans were decreased while their soluble dietary fiber content was increased. This enzyme treatment was found to be effective in reducing the initial crumb firmness and water activity and in increasing the batter viscosity, gelatinization temperature, specific volume, porosity and sensorial characteristics of the cakes. No differences were observed in the batter's specific gravity and the cake crumb's moisture content and Browning Index (BI). The level of endoxylanase treatment did not alter significantly (P < 0.05) the functional properties of the brans and the quality characteristics of the cakes probably because the treatment time (30 min) was too short to indicate a significant effect. The optimum cake characteristics were obtained when oat bran treated with 70 ppm endoxylanase was used. Overall, endoxylanase treated brans could be incorporated into cakes and improve their nutritional and quality characteristics. The objective of the present study was to evaluate the effect of the enzyme (xylanase) treatment of 2 commonly used cereal brans (oat and rice) in order to develop a functional bakery product. By using cereal bran one can upgrade agricultural products and by‐products for use as food ingredients without any additional cost. Furthermore, the treatment of raw cereal brans with xylanase alters the composition and functional properties of brans, influencing the characteristics of the final product as well. Endoxylanase treated brans were found to have improved functional properties that are essential for a successful incorporation, as well as higher nutritional value. The results of the study show the potential of using enzymes to modify underutilized sources of raw materials that can be properly incorporated in baked goods, improving their nutritional value and quality characteristics. The developed procedure and results can be used by the bakery industry to make high fibre and low cost bakery products with improved sensorial characteristics that are appealing to the consumers.

GLAZING EFFECTS ON BREAD CRUST AND CRUMB STALING DURING STORAGE

ABSTRACTThe uses of cornstarch, egg white, skim milk and shortening as glazes on bread surfaces were investigated for its ability to reduce bread staling. Four concentrations of glazes were applied to sweet bun surfaces. Bread crumb and crust samples were measured for its firmness and moisture during storage. The rates of change in firmness and moisture contents of crumb and crust with storage time were analyzed by comparing with nonglazed breads as control. While both crumb and crust firmness and the crust moisture content increased with storage time, crumb moisture content decreased significantly (P &lt; 0.05). The application of cornstarch, egg white and skim milk was found to be effective in reducing crumb firmness from 7.4 to 26.0% and retain some crumb moisture content (of about 1%) during the storage period of 6 days. This suggests that the storage properties of bread can be improved with the application of these glaze materials.PRACTICAL APPLICATIONSThe use of glaze materials in baked products may provide more than an aesthetic function of creating appearance appeal. This research shows that glazing of breads reduces bread staling through its ability to retain crumb moisture and reduce crumb firming. This finding provides means of improving bread quality in terms of textural properties and its shelf life by means of processing and with no alter in ingredients' formulation.

Staling of Cereal Bran Enriched Cakes and the Effect of an Endoxylanase Enzyme on the Physicochemical and Sensorial Characteristics

The staling of cakes enriched with untreated brans and endoxylanase-treated brans was evaluated by monitoring the changes in physicochemical, thermal, and sensorial properties of cakes during 7-d storage. Oat and rice bran were treated with different levels (0, 70, and 700 ppm) of an endoxylanase enzyme and added to cakes on 30% flour weight basis. Moisture losses, water activity, crumb firmness, starch retrogradation, and sensorial characteristics were used as staling indicators. Avrami-type equations were efficiently used for modeling the starch retrogradation kinetics, while linear models most adequately described crumb firming kinetics. Cake staling induced an increase in crumb firmness and enthalpy of amylopectin retrogradation, and a decrease in crumb moisture and sensory quality and acceptability scores of cakes. Oat bran-containing cakes better maintained their characteristics compared to the ones containing rice bran along the 7-d storage. Endoxylanase treatment of brans delayed the changes naturally induced during staling in crumb moisture content, amylopectin retrogradation enthalpy, and crumb firmness in the respective cakes. Deterioration of the sensorial characteristics was slower for the cakes containing endoxylanase-treated brans, as well. The level of endoxylanase treatment did not differentiate significantly (P < 0.05) any of the staling indicators. Overall, this study demonstrated that addition of endoxylanase-treated brans can result in cakes with improved nutritional characteristics and increased shelf life. The results of the study show the potential of using enzymes to modify underutilized food sources that can be properly incorporated in baked goods, improving their nutritional value, their quality characteristics, and providing longer shelf life. The developed procedure and results can be utilized by the bakery industry to make high fiber and low cost bakery products with improved sensorial characteristics that are appealing to the consumers.

Effect of dietary fibre enrichment on selected properties of gluten-free bread

Abstract The enrichment of gluten-free baked products with dietary fibre seems to be necessary since it has been reported that coeliac patients have generally a low intake of fibre due to their gluten-free diet. In the present study different cereal fibres (wheat, maize, oat and barley) were added at 3, 6 and 9 g/100 g level into a gluten-free bread formulation based on corn starch, rice flour and hydroxypropyl methyl cellulose (HPMC). Doughs were evaluated based on consistency, viscosity and thermal properties. Results showed that maize and oat fibre can be added to gluten-free bread with positive impact on bread nutritional and sensory properties. All breads with 9 g/100 g fibre increased the fibre content of control by 218%, but they were rated lower than those with 3 and 6 g/100 g fibre due to their powdery taste. The formulation containing barley fibre produced loaves that had more intense color and volume comparable to the control. During storage of breads a reduction in crumb moisture content and an increase in firmness were observed. The micrographs of the crumb showed the continuous matrix between starch and maize and/or oat fibre obtaining a more aerated structure.

Effect of the Addition of Different Dietary Fiber and Edible Cereal Bran Sources on the Baking and Sensory Characteristics of Cupcakes

The effect of successively replacing (10%, 20%, and 30%) wheat flour with dietary fiber (DF) from wheat, oat, barley, and maize or cereal bran (CB) from wheat, oat, and rice on cake batter, final cake quality parameters, as well as on product shelf-life was studied. Batter viscosity (control, 2.96; wheat fiber 30%, 20.21; rice bran 10%, 0.47 Pa sn), cake-specific volume (control, 2.27; wheat fiber 20%, 2.83; rice bran 30%, 1.94 cm3/g), porosity (control, 0.75; wheat fiber 30%, 0.81; rice bran 30%, 0.69), and crumb moisture content (control, 20.07%,; wheat fiber 30%, 26.45%; oat bran 30%, 13.89%) increased significantly (P < 0.05) with DF addition but decreased with CB addition. Addition of DF resulted in softer crumb texture (Control, 4.20 N; wheat fiber 20%, 3.19 N), while CB addition increased crumb firmness (rice bran 30%, 10.84 N), respectively. Minor differences were observed in the crumb and crust color of the DF cakes with respect to the control. Addition of CB decreased the L values of crumb color significantly and the decrease increased with increased level of CB incorporation. DF addition led to cakes with greater acceptance by panelists than CB addition, similar to the control. DF cakes stored in polyethylene bags at 25 °C and 60% relative humidity for 6 days showed delayed moisture loss and lower firmness compared to CB cakes. The optimal level of incorporation based both on the objective and sensory characteristics results was found 20% for DF and 10% for CB, respectively. Concluding, by incorporating DF or CB properly, cakes with improved nutritional value can be manufactured.

Quality and textural behaviour of par‐baked and rebaked cake during prolonged storage

SummaryThe effect of par‐baking and refrigerator storage on the quality of cake was investigated. Quality evaluation of rebaked cakes was performed by using physical, chemical and instrumental texture profile analysis. Cakes were par‐baked for 15, 20 and 25 min at 175 °C and then they were stored at refrigerator temperature (4 °C) for 30, 60 and 90 days, wrapped with two polyethylene bags. After storage, par‐baked cakes were rebaked at 175 °C and were subjected to analysis. Par‐baking and intermediate storage time had a significant effect on baking loss, crumb moisture content, colour, symmetry index and textural properties of cake. The increase in the par‐baking time led to a decrease in the baking loss and an increase in the moisture content of cake. Specific volume, moisture content, L colour value and symmetry index significantly decreased with increasing intermediate storage time, while baking loss significantly increased. However, regarding the crumb hardness, cohesiveness, springiness, gumminess and chewiness, the results indicated that the best result was obtained when cakes were baked for 15 min at the par‐baking stage. Overall, the cakes became firmer, less cohesive and less dry crumb as the intermediate storage time increased, whereas springiness increased.

Physical properties of breads containing hydrocolloids stored at low temperature: II—Effect of freezing

Bread types such as dough samples (DB), semi-baked (SB) and full-baked (FB) breads were frozen stored for a week and further baked (DB or SB). Structure stabilizers such as xanthan (X), hydroxypropylmethylcellulose (HPMC), guar gum (GG) or locust bean gum (LB) were also added to the dough. Baking stage is important for bread quality after storage; additionally hydrocolloids provide stability in many frozen foods. Fresh bread samples were prepared for comparison. Yield in baked product, dough characteristics, specific volume, porosity, textural properties of both crumb/crust, moisture content of crumb/crust and finally crust thickness and colour were measured. Data grouping was performed using PCA analysis and correlations among the properties measured were found. X and LB addition resulted in the most stable dough, since strength and dough extensibility change during storage was low. Hydrocolloid stabilizers’ (HS) influence on final bread characteristics was more pronounced in DB and SB breads. Crust moisture content was higher in SB breads, and it reached values 11–19% higher in control and galactomannan-containing breads than in DB respective samples. Bread specific volume was highly correlated to the crumb moisture content, to the crumb/crust textural characteristics and to the yield in the baked product. It was not correlated to crust moisture content and thickness. Porosity and bread colour were not correlated to any of the other properties. Bread type and HS selection are important factors for improving stability during storage.

Characteristics of French Bread Baked from Wheat Flours of Reduced Starch Amylose Content

ABSTRACTWheat genotypes of wild type, partial waxy, and waxy starch were used to determine the influence of starch amylose content on French bread making quality of wheat flour. Starch amylose content and protein content of flours were 25.0–25.4% and 14.3–16.9% for wild type; 21.2 and 14.9% for single null partial waxy; 15.4–17.1% and 13.2–17.6% for double null partial waxy; and 1.8 and 19.3% for waxy starch, respectively. Wheat flours of double null partial waxy starch produced smaller or comparable loaf volume of bread than wheat flours of wild type and single null partial waxy starch. Waxy wheat flour, despite its high protein content, generally produced smaller volume of bread with highly porous, glutinous, and weak crumb than wheat flours of wild type and partial waxy starch. French bread baked from a flour of double null partial waxy starch using the sponge‐and‐dough method maintained greater crumb moisture content for 24 hr and softer crumb texture for 48 hr of storage compared with bread baked from a flour of wild type starch. In French bread baked using the straight‐dough method, double null partial waxy wheat flours with protein content &gt;14.3% exhibited comparable or greater moisture content of bread crumb during 48 hr of storage than wheat flours of wild type starch. While the crumb firmness of bread stored for 48 hr was &gt;11.4 N in wheat flours of wild type starch, it was &lt;10.6 N in single or double null partial waxy flours. Wheat flours of reduced starch amylose content could be desirable for production of French bread with better retained crumb moisture and softness during storage.

Influences of Baking and Thawing Conditions on Quality of Par‐Baked French Bread

ABSTRACTWe examined the effects of baking time and temperature for the preparation of par‐baked French bread, and of thawing and second baking conditions on the characteristics of bread prepared from par‐baked bread. Par‐baked French bread with loaf volume and crumb structure comparable to fully baked bread (control) was obtained with ≥6 min baking at 218°C, which increased the crumb temperature to 97°C. Freezing, thawing, and second baking of par‐baked bread decreased loaf volume by ≥100 mL. The second baking time of par‐baked bread, which was adjusted to have the bread crumb subjected to 97°C for 14 min based on the crumb temperature profile, produced a darker crust of bread compared with the control. The par‐baked bread with 6 min of initial baking at 218°C and frozen at ‐30°C required 12 min of second baking after thawing for 180 min to ≈20°C to produce crust color, crumb moisture, and firmness comparable to that of the control. When thawing time of par‐baked bread was shortened from 180 to 0 min, the second baking time required to yield crust color similar to the control increased from 12 to 16 min. The crumb moisture content was higher in bread baked for 16 min without thawing par‐baked bread than those baked after thawing for 45 or 180 min. Lowering the initial baking temperature of par‐baked bread from 246 to 163°C with the adjustment of baking time from 4 to 12 min decreased crumb firmness of the re‐baked (218°C, 16 min) bread from 2.5 to 1.5 N at 2 hr after baking and from 9.8–10.3 to 6.2–6.3 N at 48 hr.

Staling of cake prepared from rice flour and sticky rice flour

MiGao, prepared from rice flour and sticky rice flour, is a kind of steam cooked Chinese cake. Staling of MiGao resulted in loss in texture and eating quality. Moisture content, water activity, texture, differential scanning calorimetry thermograms and sensory quality of MiGao, were monitored and were found to be significantly affected by cake staling when stored at room temperature for up to 5 days. The moisture content decreased after 2 days of storage and during the following days the crumb moisture content remained practically unchanged. Firmness was developed mainly during the first day of storage, remained at a similar level from day 2 to 3 and increased slightly after the third day of storage. A decrease in sensory quality and acceptability of the MiGao was observed during storage. Differential scanning calorimetry was used to follow changes of starch retrogradation in MiGao crumb. Amylopectin recrystallisation in MiGao continued to increase during storage.

Effect of partial baking, storage and rebaking process on the quality of white pan bread

SummaryThe effect of par‐baking, antimicrobial additive (calcium‐propionate) and refrigerator storage on the aging behaviour and quality of white pan bread was evaluated. Breads were par‐baked for 10, 15, 20 min at 230°C, with and without Ca‐propionate (0.2%), and were stored at refrigerator temperature (4°C) for 7, 14, 21 days, wrapped with two polyethylene bags. After storage, rebaked breads were subject to moisture, baking loss, volume, hydration capacity, softness, total titratable acidity (TTA) and colour analysis. Addition of Ca‐propionate significantly decreased crust moisture content, baking loss, specific volume, hydration capacity and softness values of white pan bread, while crumb moisture content, acidity and a colour value significantly increased. Initial baking time of rebaked white pan bread had a significant effect on moisture, specific volume, hydration capacity, softness, TTA and colour of bread. Regarding the crumb softness, 10 min of initial baking time gave the softest white pan bread crumb. The increase in the time of intermediate storage of the par‐baked bread leads to a decrease in the quality of the resulting full baked bread, namely a loss in the moisture content, softness and an increase of the baking loss, specific volume. The rebaked white pan bread, which was par‐baked for 10 min and stored for 7 and 14 days at refrigerator temperature, gave softer crumb than the control group.

Understanding and Modeling the Processing‐Mechanical Property Relationship of Bread Crumb Assessed by Indentation

ABSTRACTMeasuring fundamental mechanical parameters such as Young's modulus and critical stress is a straightforward and valid approach to evaluating the physical texture of breadcrumb. The objectives of this study were to evaluate whether such fundamental mechanical properties could be measured by indentation techniques such as the AACC crumb firmness method, and then to alter breadmaking conditions so as to model the relationship between these indentation mechanical properties as a function of crumb moisture content and crumb density. Bread was baked according to a short dough process using Canadian western red spring (CWRS) wheat flour. Factors considered in the design of experiments were proofing time, water absorption, crosshead speed, and indenter diameter. Young's modulus and critical stress, measured with 12‐ and 20‐mm cylindrical indenters, were well covalidated with those obtained from a standard compression test. With increases in proofing time and water absorption, a more porous and compliant bread texture led to decreasing Young's modulus and critical stress. Our results revealed a good mapping of mechanical properties to crumb moisture content and density that were correlated to breadmaking conditions, thus permitting more precise prediction of the mechanical properties that determine bread texture.

Influence of Amylose Content on Properties of Wheat Starch and Breadmaking Quality of Starch and Gluten Blends

ABSTRACTThe effects of amylose content on thermal properties of starches, dough rheology, and bread staling were investigated using starch of waxy and regular wheat genotypes. As the amylose content of starch blends decreased from 24 to 0%, the gelatinization enthalpy increased from 10.5 to 15.3 J/g and retrogradation enthalpy after 96 hr of storage at 4°C decreased from 2.2 to 0 J/g. Mixograph water absorption of starch and gluten blends increased as the amylose content decreased. Generally, lower rheofermentometer dough height, higher gas production, and a lower gas retention coefficient were observed in starch and gluten blends with 12 or 18% amylose content compared with the regular starch and gluten blend. Bread baked from starch and gluten blends exhibited a more porous crumb structure with increased loaf volume as amylose content in the starch decreased. Bread from starch and gluten blends with amylose content of 19.2–21.6% exhibited similar crumb structure to that of bread with regular wheat starch which contained 24% amylose. Crumb moisture content was similar at 5 hr after baking but higher in bread with waxy starch than in bread without waxy starch after seven days of storage at 4°C. Bread with 10% waxy wheat starch exhibited lower crumb hardness values compared with bread without waxy wheat starch. Higher retrogradation enthalpy values were observed in breads containing waxy wheat starch (4.56 J/g at 18% amylose and 5.43 J/g at 12% amylose) compared with breads containing regular wheat starch (3.82 J/g at 24% amylose).

Moisture Redistribution and Phase Transitions During Bread Staling

ABSTRACTStandard white breads were stored with or without crust at 25°C in hermetic pouches. During two weeks of storage, the crumb moisture content and water activity (aw) decreased significantly when stored with crust. When stored without crust, moisture content and aw remained relatively unchanged. The causes of the initial firming of both breads over zero to seven days were not conclusive. But when stored beyond seven days, bread stored with crust was significantly firmer in texture and higher in amylopectin recrystallization than bread stored without crust. Moisture redistribution from crumb to crust played a significant role. This was accompanied by a decrease in freezable water in the bread crumb stored with crust. This loss in freezable water coincided with changes in the thermomechanical profile only in the case of sample stored with crust intact (and with a significant total and freezable water loss). Bread crumb stored without crust did not change in total and freezable water and showed less change in thermomechanical transitions. The transition occurring at ≈60°C (T2) correlated with amylopectin recrystallization but it could also have been caused by moisture loss during the analysis. Moisture migration from crumb to crust greatly reduced the total and freezable water in the crumb region, resulting in a significant reduction in the magnitude of the mechanical transition at ≈0°C (T1) as well as an increase in the storage modulus.