Cake Baking in Conventional, Impingement and Hybrid Ovens

White layer cakes were baked in three types of air impingement ovens, a hybrid (microwave/air impingement) oven, and a reel oven. Cakes were evaluated based on volume, crust color, and texture. Oven heat transfer rates were measured directly, and ranged from 22.8 to 84.8 J/s m²C° for top and from 17.4 to 110.9 for bottom surfaces, exposed in the different ovens, with the conventional reel oven having the lowest values. An RSM design was used to establish optimum baking conditions for each oven. For air impingement ovens, baking time was reduced by almost half but produced cakes very similar to those from the control (reel) oven. Incorporating microwaves enabled a further reduction in baking time, to one fourth. Cakes baked with microwaves had similar color, but had 15% less volumes and firmer textures than control cakes.     

Humidity change and its effects on baking in an electrically heated air jet impingement oven

A high temperature humidity sensor was used to monitor the absolute humidity inside an electrically heated conveyorized, food service-scale, two-zone, air-jet impingement tunnel oven as commonly used by pizza chain restaurants. The oven was first operated empty, then loaded with dummy loads consisting of pans of water in perlite while baking layer cakes, and finally when baking cakes with added dummy loads. Temperature and loading affected humidity, and humidity affected final product quality. High humidity lightened cake crust color, increased volume, and raised the final moisture content of the cake. There was no significant effect of humidity on the heat transfer coefficient as determined by a standardized metal target plate. In this study, one pan of perlite approximated three pans of cake. Adding perlite dummy loads was shown to be a useful technique to quantitatively measure and to demonstrate the effect of humidity during baking. It is also a convenient way to accelerate oven load-testing without producing and discarding a large number of samples.     

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.     

Effect of different precooking methods on chemical composition and lipid damage of silver carp (Hypophthalmichthys molitrix) muscle

The influence of three precooking methods (steaming, oven‐baking and microwave‐cooking) on the chemical composition and lipid quality of silver carp fillets was evaluated. The changes in protein, fat and moisture were found to be significant for all the treatments (P ≤ 0.05). The iron content in the samples subjected to steam‐cooking increased; however, the other precooking methods did not change the mineral contents (P ≥ 0.05). The free fatty acid content of the fillets did not change by the different precooking methods, while thiobarbituric acid (TBA) values increased for oven‐ and microwave‐cooked fillets and remained constant in the steam‐cooked samples. Conjugated diene and browning colour formation levels significantly increased in the oven‐baked fillets. Oven‐baking and microwave‐cooking marginally affected the fatty acid composition of the silver carp. On comparing the raw and precooked fillets, steam‐cooking was found to be the best precooking method on retaining nutritional constituents.     

Effect of different baking modes on the physico-chemical and sensory characteristics of tandoori roti

Studies were carried out to determine the effect of baking, in different types of oven such as an earthen tendoor, a gas tandoor, an electric oven and a heated plate, on the physico-chemical and quality characteristics of tandoori roti. The studies indicated that the extent of gelatinization of starch varied depending on the type of oven used and was found to be 74.6, 78.4, 90.7 and 88.4% in roties baked in an earthen tandoor, a gas tandoor, an electric oven and a heated plate respectively. The pasting characteristics of starch, separated from the tandoori roti sample and measured using a Rapid Visco Analyzer, indicated the highest peak viscosity (36 SNU) for tandoori roti baked in an earthen tandoor and the lowest (25 SNU) for that baked in an electric oven. The concentration of high molecular weight proteins was lower in roti baked in an earthen tandoor and a gas tandoor, indicating greater dissociation of high molecular weight proteins during baking in such ovens. The sensory texture, taste and flavour of roti baked in an earthern tandoor was found to be superior to those baked in other types of ovens.     

Study of hydroxymethylfurfural and furfural formation in cakes during baking in different ovens,using a validated multiple-stage extraction-based analytical method

A procedure for extraction of hydroxymethylfurfural (HMF) and furfural from cakes was validated. Higher yield was achieved by multiple step extraction with water/methanol (70/30) and clarification with Carrez I and II reagents. Oven type and baking time strongly influenced HMF, moisture and volatile profile of model cakes, whereas furfural content was not significantly affected. No correlation was found between these parameters. Baking time influenced moisture and HMF formation in cakes from traditional and microwave ovens but not in steam oven cakes. Significant moisture decrease and HMF increase (3.63, 9.32, and 41.9 mg kg⁻¹ dw at 20, 40 and 60 min, respectively) were observed during traditional baking. Cakes baked by microwave also presented a significant increase of HMF (up to 16.84 mg kg⁻¹ dw at 2.5 min). Steam oven cakes possessed the highest moisture content and no significant differences in HMF and furfural. This oven is likely to form low HMF and furfural, maintaining cake moisture and aroma compounds.     

Influence of Final Baking Technologies in Partially Baked Frozen Gluten‐Free Bread Quality

The effect of final baking in convection oven (FBC), microwave oven (FBM), and microwave oven with susceptor packaging material (FBMS) on partially baked (PB) frozen gluten‐free bread characteristics was investigated. Specific volume and crust color of loaves were measured at day 0. Bread moisture, water activity, and crumb and crust texture (at 15, 45, and 90 min after baking) were analyzed at day 0 and after 28 d of frozen storage (?18 °C). Volatile compounds from breads baked in convection oven or microwave oven with susceptor packaging material were also evaluated. Bread finally baked in convection oven or in microwave oven with susceptor packaging increased crust browning. Crumb and roll hardness increased with time after final baking (measured at 15, 45, 90 min) and after 28 d of frozen storage. Bread finally baked in microwave oven was the hardest, due to high water losses. At day 0, bread finally baked in convection oven had softer crumb than bread finally baked in microwave oven with susceptor packaging but, after 28 d of frozen storage, there were no differences between them. Moreover, FBC and FBMS rendered gluten‐free breads that could not be distinguished in a triangular test and had the same volatile compounds profile. In conclusion, FBMS could be an alternative to FBC.     

A quality comparison of breads baked by conventional versus nonconventional ovens: A review

Undesirable qualities of breads baked in nonconventional ovens have been observed by most researchers. The altered heat and mass transfer patterns and much shorter baking times associated with microwave radiation resulted in a crustless product with tougher, coarser, but less firm texture. Insufficient starch gelatinization, microwave-induced gluten changes, and rapidly generated gas and steam caused by the heating mode could be reasons for quality changes in the microwave-baked breads. Although breads baked in an electrical resistance oven did not brown, their interior characteristics and shelf-life were superior to those of products baked in a conventional oven. Bread with a superior keeping quality was obtained using an air impingement convection oven. The determination and explanation of the physical and biochemical changes that occur in products during baking in conventional versus nonconventional ovens are fruitful areas for future research.     

Quality Attributes of Muffins: Effect of Baking Operative Conditions

Muffins are sweet baked products highly appreciated by consumers because of their soft texture and characteristic taste. The aim of this work was to study the influence of baking conditions on muffins’ quality. Surface crust color was monitored during baking tests at oven temperatures ranging from 140 to 220 °C, and browning kinetics was modeled by means of a browning index, BI, which follows a logistic model; a joint analysis of core temperature profile and BI curve can assist in the prediction of baking time. Finally, weight loss, crust/crumb ratio, crumb and crust moisture content, porosity, crumb and global densities, and texture were measured in the already baked muffin. The water content in the crumb remains almost constant, while considerable dehydration occurs in the crust. Finally, the results showed that intermediate oven temperatures led to a more porous, aerated, and soft crumb, with intermediate textural properties.     

Use of applied air pressure to improve the baking properties of whey protein isolates in angel food cakes

Whey protein isolate (WPI) possesses limited application in angel food cake baking compared to liquid egg white (LEW). This study was conducted to determine whether applying air pressure in the oven during baking would improve the baking properties of WPI in angel food cakes. A special oven was designed for baking at oven air pressures up to 1.5 bar. Control angel food cakes were formulated with LEW (100/0) as its protein source and WPI-containing cakes were formulated with a mixture of 75 mL/100 mL LEW and 25 mL/100 mL WPI solution (75/25) or a mixture of 50 mL/100 mL LEW and 50 mL/100 mL WPI solution (50/50). Cakes were baked at atmospheric air pressure (AP) and at constant applied air pressure (CAP) or variable applied air pressure vs. baking time (VAP) to prevent overexpansion and collapse of WPI-containing cake batter. Cakes 75/25 and 50/50 baked at VAP exhibited improved physical, textural and sensory properties compared to those baked at AP or CAP conditions. Cakes 75/25 baked at VAP compared well with control angel food cakes baked at AP. Although 50/50 cakes baked at VAP were improved slightly over those baked at AP, none of them exhibited satisfactory properties. Therefore, additional research is needed to optimize baking conditions for cakes formulated with less than 75 mL/100 mL LEW.     

Effects of Microwave/Convection Baking and Pan Characteristics on Cake Quality

The quality of devil's food cake baked in a microwave/convection oven using different oven conditions and pan characteristics was assessed by sensory and objective methods. The most important factors were the number of layers baked at a given time and the baking pan characteristics, followed by initial oven temperatures. Crust color, moistness and cake symmetry were affected by these conditions. For example, single layers received a lower sensory score and had sticky and less red crusts than double layers. Cakes baked in glass-polyester microware pans were peaked, whereas those baked in aluminum pans were flat. Although slight differences in quality were found by both sensory and objective evaluations, all cakes were acceptable.     

Apparent Heat Transfer in a Forced Convection Oven and Properties of Baked Food

Parameters for expressing the heating performance and baking results of sponge cakes dependent on heating performance in a forced convection oven were studied. The heating performance of a forced convection oven may be expressed by the apparent heat transfer coefficient which was measured at various air temperatures and velocities. Both the air velocity and temperature of the circulating air affected the apparent heat transfer coefficient in a forced convection oven and determined the final properties of the baked food. The effects of these parameters on sponge cakes baked in the forced convection oven were observed.     

Effect of oven temperature profile and different baking conditions on final cake quality

This study discusses the effect of airflow on oven temperature profiles, the internal cake temperature and the final cake quality. It was found that the presence of airflow reduced the oscillation in the oven temperature profile from 12.98–30.27% to 3.17–4.02%. The bottom of the oven chamber experienced the greatest reduction in temperature oscillation in the presence of airflow. During the second stage of baking with airflow, the heating rate was increased from 5.07 to 7.52 °C min^?1 and 8.35 °C min^?1 to the increase of the baking temperature from 160 to 170 °C and 180 °C, respectively. The cake volume expansion rate was also increased 5–10% during second stage when baking with airflow condition. The cakes baked in the presence of airflow had a more porous crumb texture and lower moisture content compared to the cakes baked without airflow.     

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.     

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.     

Relative importance of moisture migration and amylopectin retrogradation for pound cake crumb firming

Moisture migration largely impacts cake crumb firmness during storage at ambient temperature. To study the importance of phenomena other than crumb to crust moisture migration and to exclude moisture and temperature gradients during baking, crustless cakes were baked using an electrical resistance oven (ERO). Cake crumb firming was evaluated by texture analysis. First, ERO cakes with properties similar to those baked conventionally were produced. Cake batter moisture content (MC) was adjusted to ensure complete starch gelatinisation in the baking process. In cakes baked conventionally, most of the increase in crumb firmness during storage was caused by moisture migration. Proton nuclear magnetic resonance (¹H NMR) showed that the population containing protons of crystalline starch grew during cake storage. These and differential scanning calorimetry (DSC) data pointed to only limited amylopectin retrogradation. The limited increase in amylopectin retrogradation during cake storage cannot solely account for the significant firming of ERO cakes and, hence, other phenomena are involved in cake firming.     

Effect of Radio Frequency Postdrying of Partially Baked Cookies on Acrylamide Content,Texture, and Color of the Final Product

Abstract: Effect of radio frequency (RF) postdrying of partially baked cookies on acrylamide content, texture, and color of the final product was investigated in this study. Control cookies were prepared by baking in a conventional oven at 205 °C for 11 min. Cookies partially baked for 8 and 9 min were postdried in a 27.12 MHz RF tunnel oven until attainment of the moisture content of control cookies. Internal temperature of cookies was monitored during the experiments to better explain the results. Cookies were analyzed for acrylamide content using a liquid chromatography‐mass spectrometry (LC‐MS) method. Texture measurements were performed using a Texture Analyzer, while digital image analysis was used for color measurement. The results showed that RF postdrying of partially baked cookies resulted in lower acrylamide levels (107.3 ng/g for control cookies, 74.6 ng/g upon RF postdrying of cookies partially baked for 9 min, 51.1 ng/g upon RF postdrying of cookies partially baked for 8 min). Instrumental texture analysis showed no significant difference among the texture of cookies, whereas RF postdried samples had a lower degree of browning. According to sensory evaluation results, control had a more crumbly texture, and RF postdried sample that was conventionally baked for 8 min had a slightly uncooked flavor. Practical Application: Combining radio frequency and conventional baking may provide cookie manufacturers with ability to make cookies with lower levels of acrylamide.     

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     

Optimization of bread baking in a halogen lamp–microwave combination oven by response surface methodology

The main objective of this study was to optimize the baking conditions of bread in a halogen lamp–microwave combination oven. Independent variables were the baking time (4, 4.5, 5, 5.5, and 6 min), the power of the microwaves (20, 30, 40, 50, and 60%), and the power of the upper and lower halogen lamps (40, 50, 60, 70, and 80%). The quality parameters measured were the weight loss, the color, the specific volume, the porosity, and the texture profile of the breads. For the optimization, the response surface methodology was used. Baking time, upper halogen lamp power, and microwave power were found to be significant in affecting most of the quality parameters. On the other hand, the lower halogen lamp power was found to be an insignificant factor. The optimum baking conditions in the halogen lamp–microwave combination oven were determined as 5 min of baking time at 70% upper halogen lamp power, 50% lower halogen lamp power, and 20% microwave power. Breads baked at the optimum condition had comparable quality with conventionally baked ones. When the halogen lamp–microwave combination oven was used, the conventional baking time of breads was reduced by 60%.     

IDENTIFICATION OF IMPORTANT PRODUCTION VARIABLES AFFECTING HARD PRETZEL QUALITY

The objective of this study was to determine the importance of raw material and processing variables that influence pretzel quality by utilizing a screening experiment design. Eleven variables were selected based on preliminary experiments, and a two‐level‐11‐factor (2 ¹¹ ) fractional factorial experimental design was used to screen the variables. Several responses were measured for dough before and after extrusion, for half‐baked and fully baked pretzels. These responses are important indicators of consistency and quality during pretzel processing. Results indicated that flour protein content, the amount of water added to make dough and dough mixing time were important variables influencing dough behavior. Caustic concentration affected brightness of half‐baked pretzels but did not influence the color of the final product. Baking time was the most important factor for both half‐baked product and final product qualities. The hardness of fully baked pretzels was influenced by baking time, temperature in baking oven zone 1, drying time and drying temperature. The color of final products was significantly influenced by baking time, while both baking time and drying temperature affected the moisture content of the final product. A key observation was that none of the raw material or dough processing parameters, within the range tested, influenced final pretzel quality as defined by pretzel moisture content, hardness or color.