Effect of baking method on some characteristics of starch in pound cake crumbs

BACKGROUND: The effect of the baking process (microwave versus conventional oven) on some starch characteristics of pound cake was evaluated. Proximal chemical analysis, total resistant starch (RS), retrograded resistant starch (RS3), differential scanning calorimetry (DSC), and X‐ray diffraction (XRD) were evaluated. Pound cake, one of the major products of Mexico's bread industry, was selected for analysis because the high moisture and fat content in the beaten dough might reduce the quality defects often associated with microwave baking. RESULTS: Crumbs from microwave‐baked pound cakes contained lower moisture than crumbs from conventionally baked pound cake. Lower RS was observed in fresh microwave‐baked than conventionally baked pound cake. RS3 increased significantly in conventionally baked products stored for 8 days at room temperature, whereas slightly lower changes in RS3 were observed in the microwaved product. DSC revealed less gelatinisation in microwaved pound cake which is related to limited water availability during the microwave heating process. The crystallinity peaks present in conventionally baked pound cake might be associated with RS3 content; the resistant retrograded starch formed during storage, is reflected in the XRD pattern. CONCLUSION: Microwave‐baked pound cake crumbs showed less gelatinisation than conventionally baked pound cake crumbs. Copyright © 2007 Society of Chemical Industry     

Optimisation of formulations and infrared–microwave combination baking conditions of chestnut–rice breads

The main objective of this study was to design gluten‐free breads containing chestnut and rice flour and xanthan–guar gum blend to be baked in infrared–microwave combination oven. Response surface methodology (RSM) was used to optimise gluten‐free bread formulations and processing conditions. Weight loss, firmness, specific volume and colour change of the breads were determined. Rice flour mixed with different proportions of chestnut flour and different emulsifier contents were used to prepare breads. The gluten‐free formulations were baked using different upper halogen lamp powers, microwave powers and baking time which were varied from 40% to 80%, 30% to 70% and 9 to 17 min, respectively. Gluten‐free breads and wheat breads baked in conventional oven were used for comparison. Breads containing 46.5% chestnut flour and 0.62% emulsifier and baked using 40% infrared and 30% microwave power for 9 min had statistically comparable quality with conventionally baked ones.     

烘焙豆粉对烘焙产品的品质影响研究

采用粉质仪法和拉伸仪法及烘焙实验,研究了烘焙豆粉对小麦面团流变学特性和面包及蛋糕品质的影响.结果表明,在面包粉加6 %烘焙豆粉,蛋糕粉加10 %烘焙豆粉的用量下,添加烘焙豆粉后,面团的吸水率和延展度提高,耐揉指数、粉质质量指数、抗拉伸阻力及拉伸比例降低,面包和蛋糕的表皮颜色、质地及蛋糕的组织结构都有所改进.     

Effect of baking temperature/time conditions and dough thickness on arabic bread quality

A new scoring system for the evaluation of Arabic bread is presented which allows discrimination between flour samples. This system is suitable for the evaluation of bread in commercial bakeries. Dough thickness and baking temperature/time conditions were varied: doughs sheeted to <3.0 mm thick require baking temperatures higher than 500°C whereas doughs that are thicker than this will benefit from temperatures lower than 500°C. Thinner doughs baked at higher temperatures for shorter times produced better quality bread. The processing variables identified as being optimal in this study were incorporated into a test baking method. This method gave reproducible results and greater discrimination between flour samples than a previous method.     

食品的微波焙烤技术

微波与极性分子及食品中带电粒子相互作用而生热,微波加热具有省时、节能、改善营养质量和提高消费者对食品的接受性等优点,但是目前微波焙烤食品还存在一系列问题,如微波食品的体积小,质地粗糙、坚硬,无褐变,香味形成难等,这也是目前食品微波焙烤技术的研究热点。本文综述了食品特性对微波焙烤的影响,微波焙烤与传统焙烤的差别以及目前常用的解决微波焙烤食品问题的方法。     

Effects of microwave frying and different flour types addition on the microstructure of batter coatings

In this study, the influences of microwave frying and various flour types on microstructure of batter coatings were investigated. Control batter formulation contained only wheat and corn flour. To determine the effects of different flour types, 30% of the corn and wheat flour mix was replaced with chickpea, rice or soy flours. Frying was performed in microwave oven at 365 W (70%) power level for 1.5 min after bringing the oil temperature to 180 ± 1 °C. Samples were also fried in a conventional fryer at 180 °C for 1.5 and 5.0 min for comparison. Microwave fried samples had higher specific bulk volume and porosity values and also smoother inner surface as compared to conventionally fried samples. Porosity values of different batter formulations were in the range of 0.425–0.484 in 1.5 min microwave fried chicken samples and 0.348–0.392 in 5.0 min conventionally fried ones. Microwave fried samples had comparable or lower hardness values than the conventionally fried ones depending on the flour type used in batter formulation. Microstructure of fried batter was different for different batter formulations. Microwave fried control and chickpea flour containing batter provided formation of larger gas cells on the outer surface. Soy flour containing batter resulted in smallest size gas cells for both frying methods.     

Effect of temperature and time on the formation of acrylamide in starch-based and cereal model systems,flat breads and bread

Dry starch systems, containing varying amounts of asparagine and glucose, freeze-dried rye-based flat bread doughs, flat bread and bread, were baked at varying temperatures and times according to central composite designs. In the starch-based model system the amount of acrylamide went through a maximum when the level of asparagine increased. No such maximum was found for glucose. In the starch system, freeze-dried flat bread doughs and flat breads, the amount of acrylamide formation went through a maximum at approximately 200 °C, depending on the system and the baking time. The amount of acrylamide was reduced at long baking times. However, in bread crust, the amount of acrylamide increased with both baking time and temperature in the interval tested.     

Acrylamide formation in different batter formulations during microwave frying

Acrylamide, a probable human carcinogen, is found to be formed in a wide range of fried foods. In this study, the effects of microwave frying on acrylamide formation in the coating part of chicken were investigated. It was also aimed to determine the effects of various flour types (soy, chickpea and rice flour) in batter formulations on the acrylamide formation and on the color of fried chicken. Usage of all flour types except soy flour resulted in approximately the same moisture content and color development after 1.5 min of microwave frying. Acrylamide contents of batter parts of 1.5 min microwave fried samples having different flours were similar. Microwave frying provided lower acrylamide content and lighter color as compared to those fried conventionally for 5 min for all types of flours. This reduction in acrylamide level was the highest (34.5%) for rice flour containing batter.     

A COMPARISON OF THE FARINOGRAPH AND A MODIFIED SHEAR-PRESS FOR MEASURING THE RHEOLOGICAL PROPERTIES OF DOUGH AND ITS FINISHED PRODUCTS1

The development of a single texture testing instrument for determining the complicated properties of dough and the textural characteristics of the final product of dough will eliminate the need for a series of specialized instruments. The farinograph and a modified shear-press were used to determine the rheological properties of doughs made from 15 mixtures of all purpose wheat flour, hard wheat flour and 6% soy fortified wheat flour adjusted with 54.7, 58.0, 61.1, 64.6 and 67.9% water absorptions. The shear-press was also used to determine the textural characteristics of the finished products. The shear-press was found to be equal to the farinograph in providing information on certain rheological properties of dough, and high correlations were obtained between these ‘texturegrams’ and farinogram parameters. For instance, the correlation between “viscoelasticity” per texturegram and “maximum consistency” per farinogram was 0.982; between “viscoelasticity” per texturegram and “elasticity” per farinogram was 0.969; and the correlation between “stability of viscoelasticity” per texturegram and “twenty minute drop” per farinogram was 0.941. The adhesive and cohesive properties of dough obtained from shear-press texturegrams explained 88.4% of the variance of the hardness of the end-products. The consistency and elasticity of dough obtained from farinograms explained 90.6% of the variance of the hardness of the end-products. If the method of water absorption and mixing of flour could be standardized, the shear-press could be utilized both for predicting rheological properties of bakery products from determinations on doughs as well as direct evaluations of the finished products.     

Production of acrylamide in agricultural products by cooking

Some model studies were performed using various agricultural Products, to clarify the relation between cooking conditions and production of acrylamide (AA). Disc chips made from dried mashed potato, corn meal, wheat flour, rice flour (jyohshin-ko) and glutinous rice flour (shiratama-ko), and dried sesame (arai-goma) and dried almond were baked at 120-200 degrees C for 5-20 min, and the samples were analyzed for the levels of AA. When the samples were baked for 10 min, the highest production of AA was observed at 180-200 degrees C. When the samples were baked at 180 degrees C, AA levels in agricultural products except sesame were highest after baking for 10 min. Vegetables and fruit were baked at 220 degrees C for 5 min with a oven, high AA concentrations were found in baked potato, asparagus, pumpkin, eggplant and green gram sprouts. Concentrations of AA in potato, asparagus and green gram sprouts baked after being pre-cooked by microwave irradiation were higher than those in the products baked without being precooked. On the other hand, the precooking by boiling reduced the production of AA by baking to 1/10-1/4. Acrylamide was not found in microwaved or boiled vegetables. High free asparagine concentrations in crops tended to result in high concentrations of AA being produced by heating the agricultural products.     

Changes in the Physicochemical Properties of Wheat- and Soy-containing Breads During Storage as Studied by Thermal Analyses

ABSTRACT: Adding soy ingredients to baked products influences textural and sensorial properties. The changes in physical properties of bread modified with soy flour during 7-d storage at ambient temperature were investigated using thermoanalytical techniques (differential scanning calorimetry and dynamic mechanical analysis). An increase in loaf density, moisture content, and FW content, and a decrease in amylopectin recrystallization were observed with increased addition of soy flour. Addition of soy shifted the main thermal transition (0 °C, mainly due to ice melting) to slightly lower temperatures (both in differential scanning calorimetry and dynamic mechanical analysis analysis) and decreased its temperature range (increased homogeneity). These observations suggest a role for soy in modulating bread staling.     

TEXTURAL PROPERTIES OF RESTRUCTURED BEEF PRODUCTS WITH FIVE BINDERS AT FOUR ISOTHERMAL TEMPERATURES1

Texture profile analysis (TPA) and shear force of restructured beef products with one of five binders (isolated soy protein, sodium caseinate, waxy modified corn starch, carrageenan, and oat flour) were analyzed at 35, 45, 55 and 65 C. Hardness, cohesiveness, springiness, gumminess, and chewiness were significantly affected (p<0.05) by binders, temperatures and their interactions. Hardness and gumminess showed no significant (p<0.05) differences among binders and temperatures below 45C, but each increased between 45 – 65C. Isolated soy protein gave the highest hardness and gumminess values; oat flour, the lowest at 55 and 65C. Except for oat flour, cohesiveness, springiness and chewiness decreased from the raw state until 45C, and then increased. Oat flour gave the highest values for cohesiveness, springiness and chewiness < 45C; the lowest at 55 and 65C. Oat flour gave the lowest shear force (N) values at 55 and 65C. Conclusions were reached that the influence of these binders on the textural parameters of restructured beef products was temperature-dependent.     

Baking High-Ratio White Layer Cakes with Microwave Energy

Microwave energy was evaluated as a means of baking high-ratio white-layer cakes by considering the effects of various processing conditions and amounts of ingredients. Minimal water in cakes baked with microwave energy did not result in surface collapse as with cakes baked by conventional means. As the amount of monocalcium phosphate monohydrate in the baking powder blend was increased, volume and specific volume decreased and crumb firmness and internal score increased. There was no evidence of any significant internal nor surface batter flow in the conventional cake, while in the microwave cake considerable batter flow was observed on the surface and internally in the upper central regions of the cake. Scanning electron micrograph showed differences in cell structure between both types of cake. The cells in the center of the cake baked with microwave energy were more irregular and had thicker cell walls than the conventional cake.     

Optimization of microwave baking of model layer cakes

 Response surface methodology was used to optimize the formulation of microwave-baked cakes. The independent variables were water content, emulsifier content baking time, oven power, shortening content and starch type. The quality factors evaluated were specific gravity of batter and volume index, uniformity index and tenderness of the crumb. Constraints for quality factors were obtained by conventional baking of American Association of Cereal Chemists high-ratio cake formulation. Multiple contour plots showed the optimum region for various water and shortening combinations at different emulsifier, time and power levels. Cakes formulated with wheat starch, containing 0.3% polysorbate 60, 133.7% water and 45.2% shortening (flour substitute basis), baked for 6 min at 100% power yielded acceptable cakes that can compete with conventionally baked cakes. Rice and corn cakes had lower quality than conventionally baked high-ratio cakes. Power was found to be the most efficient independent variable affecting all the dependent variables. Received: 26 August 1999 / Revised version: 11 October 1999     

Halogen lamp–microwave combination baking of cookies

The effects of halogen lamp–microwave combination baking on the quality of cookies in terms of texture, color and spread ratio were studied. In addition, gelatinization and pasting properties of cookies baked in different ovens were assessed by using a Rapid Visco Analyzer. The hardness values of the cookies increased with increasing baking time and/or halogen power. The microwave power also contributed to cookie hardness. The lightness values of the cookies decreased, while the a* and E values increased linearly during baking at different halogen lamp and microwave powers. The spread ratio of conventionally baked cookies was significantly lower than that of the other cookies. Halogen lamp power, microwave power and baking time were found to have a significant effect on the spread ratio of the cookies. The moisture contents of the cookies decreased during baking as the halogen lamp and/or the microwave power level increased. The best baking condition in a halogen lamp–microwave combination oven to produce cookies having similar quality parameters as conventionally baked ones was baking at 70% halogen lamp and 20% microwave power levels for 5.5 min. The baking time of these cookies is half of that required in conventional baking.     

EFFECTS OF BAKING PARAMETERS ON THE WHITE LAYER CAKE QUALITY BY COMBINED USE OF CONVENTIONAL AND MICROWAVE OVENS

The effects of combined conventional and microwave oven baked white layer cake characteristics were studied. Two types of commercially milled wheat flour, white (A) and whole wheat (B), were used. The modified white layer cake making method was used for conducting the cake baking trials. The conventional baking times (8 or 11 min), microwave power (400 or 600 W) and microwave baking time (30, 40, or 50 s) were chosen as baking parameters. Conventional baking was applied to form the cake crust before baking with the microwave oven used to form the crumb of the cakes. The performance of combination baking was compared with the performance of conventional baking. The volume, bake loss, internal factors, and crust color of cakes were evaluated as quality characteristics. The bake losses of cakes using the combination of short oven times and low microwave power for selected microwave times were smaller than the bake losses of the control cakes for both flours. Long oven times and low microwave power increased the specific volume of cakes. Cakes baked from flours A and B exhibited similar internal properties. Oven time significantly affected the crust color of cakes made with flour A. The crust color of cakes made with flour B was similar to the crust color of control cakes. Using a combination of conventional and microwave baking produces cakes with qualities equivalent to the qualities of cakes produced with conventional baking.     

Rheological and textural properties of gluten-free doughs made from Andean grains

The objective of this research was to evaluate the rheological and textural properties of gluten-free doughs based on potato starch, which was partially substituted by different proportions of quinoa (10%, 30% and 50%), kiwicha (10%, 30% and 50%) or tarwi flour (10%, 20% and 30%). The influence of the substitution on the kinetics of the leavening process was studied as well. The back-extrusion technique was used to determine rheological and textural properties of the dough, and the leavening kinetics were modelled using the Gompertz equation. The results showed that textural properties such as firmness, consistency, cohesiveness and viscosity index, as well as the consistency index of the doughs increased as the level of substitution of the Andean grain flour in the formulation increased. It was determined that the formulations with an addition of 10% and 20% for quinoa or kiwicha flour, and 10% for tarwi flour would be most suitable for developing gluten-free breads.     

Cookie- Versus Cracker-Baking—What's the Difference? Flour Functionality Requirements Explored by SRC and Alveography

The many differences between cookie- and cracker-baking are discussed and described in terms of the functionality, and functional requirements, of the major biscuit ingredients—flour and sugar. Both types of products are similar in their major ingredients, but different in their formulas and processes. One of the most important and consequential differences between traditional cracker and cookie formulas is sugar (i.e., sucrose) concentration: usually lower than 30% in a typical cracker formula and higher than 30% in a typical cookie formula. Gluten development is facilitated in lower-sugar cracker doughs during mixing and sheeting; this is a critical factor linked to baked-cracker quality. Therefore, soft wheat flours with greater gluten quality and strength are typically preferred for cracker production. In contrast, the concentrated aqueous sugar solutions existing in high-sugar cookie doughs generally act as an antiplasticizer, compared with water alone, so gluten development during dough mixing and starch gelatinization/pasting during baking are delayed or prevented in most cookie systems. Traditional cookies and crackers are low-moisture baked goods, which are desirably made from flours with low water absorption [low water-holding capacity (WHC)], and low levels of damaged starch and water-soluble pentosans (i.e., water-accessible arabinoxylans). Rheological (e.g., alveography) and baking tests are often used to evaluate flour quality for baked-goods applications, but the solvent retention capacity (SRC) method (AACC 56-11) is a better diagnostic tool for predicting the functional contribution of each individual flour functional component, as well as the overall functionality of flours for cookie- and/or cracker-baking.     

The effects of recipe formulation on the textural characteristics of microwave‐reheated pizza bases

Recipe formulation can reduce the development of inferior textural characteristics in microwave‐reheated cereal‐based products. This study assessed the impact of water‐binding agents (potato starch, pea fibre, oat fibre, locust bean gum), emulsifiers (Panodan, Nutrisoft), ingredient blends (Purawave, Microwave Improver Base) and a proteolytic enzyme (fungal protease) on the textural characteristics of microwave‐reheated pizza bases. Textural characteristics were evaluated using texture profile analysis (TPA). The attributes considered were fracturability, hardness, springiness, adhesiveness, cohesiveness, gumminess and chewiness. For this study, frozen five‐inch pizza bases topped with tomato and cheese were reheated for 120, 150 and 180 s in a domestic microwave oven. The textural characteristics of the microwave‐reheated pizza base samples were influenced by the presence of the selected agents. Overall the Panodan + oat fibre product yielded the best textural characteristics. Panodan/Nutrisoft/Purawave and Microwave Improver Base test ingredients improved the qualities of the pizza base. The recipes that showed minor enhancement of the texture contained Nutrisoft + locust bean gum/proteolytic enzyme and potato starch. The pea fibre was not advantageous and for many attributes had a disadvantageous effect. © 2000 Society of Chemical Industry     

Comparison of crumb microstructure from pound cakes baked in a microwave or conventional oven

Imaging, light microscopy and scanning electron microscopy were used to compare the microstructure of crumbs from pound cakes baked in a microwave or conventional oven. The microwave baking conditions for pound cake (240 W, 5 min) were established in previous research, conventional baked pound cakes were obtained using a swing oven at 180 °C for 40 min. Statistical differences in total cell, cell/cm² and mean cell area (P?0.05) were observed in the image analysis. Cells from microwaved pound cake crumbs were 20% larger. However, factor shape was 0.81 for both microwave and conventionally baked crumbs, and crumbs from both oven types were similar in appearance. Light microscopy revealed birefringence in crumbs from both types of pound cakes. Scanning electron microscopy revealed that the conventionally baked product had a greater amount of protein matrix however; the matrix structure of the crumb was comparable between microwave-baked and conventionally baked pound cakes. In conclusion, our results suggest that the unique aspects of pound cake dough, including its high content of fat, sugar and moisture, make it well suited to microwave baking.