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     

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.     

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.     

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.     

Comparison of pound cake baked in a two cycle microwave-toaster oven and in conventional oven

The industrial and domestic use of microwaves has increased considerably over the past few decades. New researches about the interaction of different ingredients with microwave energy, has provided insight that is helping to improve the quality of microwave-baked products. The aim of this work was to determine the best potency and baking time conditions for pound cake and apply the image analysis methodology to analyze the structure of pound cake baked in a two cycle microwave-toaster oven compared with a conventionally baked. Weight loss, density, water activity, moisture, luminosity and seven parameters of Image Analysis were measured as baking quality parameters. Optimal baking conditions for the two-cycle microwave-toaster oven were obtained using surface response analysis. The best baking conditions resulted in a low power for the first cycle (204 W for 120 s), a high power for the second cycle (937 W for 70 s), and a toasting time of 5:30 min at 200 °C. Image analysis showed a 7% reduction in the crumb cell number of the cake baked with microwaves as compared to the conventional. The two cycle microwave-toaster oven generated a product with a higher volume (11%) and higher luminosity (2%) than the conventional process. Both of them were equally preferred by consumers, scoring 4.6 (I like very much) in a hedonic sensory test.     

Optimization of halogen lamp–microwave combination baking of cakes: a response surface methodology study

The main objective of this study was to optimize processing conditions during halogen lamp–microwave combination baking of cake by using response surface methodology. The independent variables were the power of the upper halogen lamp (50, 60, and 70%), the power of the lower halogen lamp (50, 60, and 70%), the power of the microwaves (30, 40, and 50%), and the baking time (4, 5, and 6 min). Weight loss, specific volume, color, and the texture profile of the cakes were determined. The upper halogen lamp power, the microwave power, and the baking time were found to have a significant effect on the weight loss, the specific volume, and the firmness of the cakes. Cakes baked for 5 min at 60% upper halogen lamp power, 70% lower halogen lamp power, and 30% microwave power had quality comparable with conventionally baked ones, except for color. By the usage of a halogen lamp–microwave combination oven it was possible to obtain high-quality cakes by reducing the conventional baking time by about 79%.     

A model approach to starch and protein functionality in a pound cake system

Different modified wheat starches were used in a model pound cake recipe. The properties of the starches were linked to differences in batter viscosity, cake height and protein extractability during baking, collapse during cooling and final cake quality. The impact of incorporation of 30% cross-linked (CL) starches on batter properties during baking was much smaller than that of incorporation of the same level of hydroxypropylated (HP) starches. Incorporation of HP starches with various degrees of modification in the recipe caused batter viscosity during baking to start rising from 92 or 88 °C rather than at 96 °C and diminished oven rise significantly. Furthermore, the extractability of the protein in cakes containing HP starch was significantly higher. During cooling, control cake collapsed less than did CL starch-containing cake, which itself collapsed significantly less than did HP starch-containing cake. Presumably, most of the cake collapse takes place before the starch gel is formed during cooling. Protein and starch apparently function in determining cake quality, by providing the cell walls with structural material and high resistance to collapse. Starch does not prevent cake collapse, but still co-determines crumb structure, whereas a strong correlation was found between the gel-forming capacity of starch blends and intrinsic crumb firmness (r = 0.99). Furthermore, a strong negative correlation was found between springiness and percentage of extractable protein in final cakes (r = −0.95). We conclude that the combination of a protein network, formed during baking, with a starch gel, formed during cooling, makes up the crumb cell walls and determines cake quality.     

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.     

A Study on Degree of Starch Gelatinization in Cakes Baked in Three Different Ovens

The main objective of the study was to determine the effects of different baking ovens and different cake formulations on the degree of starch gelatinization during cake baking. Baking was performed in microwave, infrared–microwave combination, and conventional ovens. Starch gelatinization levels of fat free, 25% fat, and 25% Simplesse™-containing cake samples were examined using differential scanning calorimeter (DSC) and rapid visco analyzer (RVA). Both DSC and RVA results showed that increasing baking time increased gelatinization level for all baking types significantly. It was also found that the effect of fat content on starch gelatinization was different depending on the type of baking. Addition of fat reduced the degree of starch gelatinization in conventional baking. However, fat enhanced the gelatinization in microwave and infrared–microwave combination ovens. Usage of Simplesse™ as a fat replacer decreased the starch gelatinization in all types of baking significantly. There was insufficient starch gelatinization in microwave-baked cakes in which the degree of gelatinization ranged from 55% to 78% depending on formulation. On the other hand, it ranged from 85% to 93% in conventionally baked cakes. Combining infrared with microwaves increased degree of starch gelatinization (70–90%).     

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     

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.     

Quantitative analysis of macro and micro-structure of gluten-free rice cakes containing different types of gums baked in different ovens

The effects of different gums on macro-structure of gluten-free rice cakes baked in conventional and infrared–microwave (IR–MW) combination ovens were investigated by using the images obtained by scanner and scanning electron microscopy in this study. The gum types used were xanthan, guar, locust bean, κ-carrageenan and xanthan–guar blend. Cake containing no gum was used as control. It was observed that both addition of different types of gums affected the pore area fraction and percent number of pores of the rice cakes. The highest pore area fraction was obtained in cakes containing xanthan and xanthan–guar blend. Cakes baked in IR–MW combination oven had higher porosity than those baked in conventional oven. Micro-structure of gluten-free rice cakes was also analyzed. According to these results, conventionally baked cakes showed more starch granule deformations. Both granular starch residues and deformed starch structure were observed together in cakes baked in IR–MW combination oven. All of the starch granules did not lose their identity and did not disintegrate completely.     

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.     

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.     

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.     

Effects of different emulsifier types,fat contents,and gum types on retardation of staling of microwave‐baked cakes

The effects of different types of emulsifiers, gums, and fat contents on the retardation of staling of microwave‐baked cakes were investigated. First, different types of emulsifiers (DATEM, Lecigran, and Purawave) at three different fat contents (50%, 25%, and 0%) were added to cake formulations to retard staling of microwave‐baked cakes. Then, three types of gums (guar gum, xanthan gum, and methylcellulose) were added to the optimum formulations chosen. As a control, cakes formulated without any emulsifier or gum addition and baked in an conventional oven at 175°C for 25 min was used. Weight loss, firmness, soluble starch and amylose content of the cakes were used as the indicators of staling criteria. Cakes were baked in a microwave oven for 1.5 min at 100% power. Variation of staling parameters during storage of cakes followed zero‐order kinetics. Use of emulsifiers and gums helped to retard staling of microwave‐baked cakes. Fat content was found to be a significant factor in affecting variation of firmness and weight loss of the cakes during storage. DATEM and Purawave were the most effective emulsifier types. Using gums in combination with emulsifiers gave better moisture retention and softer cakes than using gums alone.     

Partial Replacement of Egg White Proteins with Whey Proteins in Angel Food Cakes

This study was conducted to investigate the effects of partial replacement of egg white proteins (EWP) with whey protein isolate (WPI) on the appearance, structure, texture, and sensory properties of angel food cakes baked in conventional and microwave/conventional ovens. Factors studied were: 1) replacement of 25% or 50% of EWP with WPI; 2) added xanthan gum (XG), methyl cellulose (MC), cupric sulfate (Cu⁺²) or sodium phosphate (PHOS); and 3) conventional vs microwave/conventional oven baking. EWP replacement cakes without additives were generally inferior to 100% EWP control cakes, whereas EWP replacement cakes with added XG were most similar to 100% EWP control cakes with respect to appearance, texture, and sensory properties and those with added MC exhibited air cell size distributions that most closely resembled control cakes. The other additives and microwave/ conventional vs conventional baking had minor effects on the quality of EWP replacement cakes.     

Monitoring the Effects of Ingredients and Baking Methods on Quality of Gluten-Free Cakes by Time-Domain (TD) NMR Relaxometry

Gluten-free products exhibit some undesirable features due to the absence of the gluten network. Effects of ingredient interactions and baking type on the food matrix have not clearly been explored. The objective of this study was to investigate the effect of ingredient and baking types on the quality characteristics of cake by using nuclear magnetic resonance (NMR) relaxometry. Carob bean flour containing gluten-free cakes formulated either with hydroxypropyl methylcellulose (HPMC) or whey protein were baked in both conventional and microwave–infrared combination ovens. Specific gravity of batters was measured and cakes were analyzed in terms of weight loss, hardness, and specific volume. Microstructure of cakes was investigated by scanning electron microscopy (SEM). NMR relaxometry was used to support the information about water retention, and water–food matrix interactions. Cakes baked in microwave–infrared (MW-IR) combination oven had some undesirable characteristics due to higher weight loss and insufficient gelatinization of starch which was supported by SEM results. Compartments of relaxation data also indicated two specific proton pools for MW-IR-baked samples, which represented gelatinized and ungelatinized parts of the cakes. Spin–spin relaxation times (T₂) were found to be good indicators for explaining the physical state and distribution of water inside the samples, having Pearson correlation of 0.96, 0.86, and ??0.98 (p?<?0.05) between monoexponential T₂ values and hardness, specific volume, and moisture, respectively.     

An instrumented oven for the monitoring of thermal reactions during the baking of sponge cake

An electric convective oven was conceived and equipped to allow monitoring thermal reactions during the baking of sponge cake. High total heat fluxes of between 6000 and 9000 W m⁻² were recorded under baking temperatures of 140-200 °C. The mapping of thermal conditions indicated satisfactory thermal homogeneity, with average temperature variations of 5 °C and maximum relative variations of the convective heat transfer coefficient of 15% on the thermal domain investigated. Internal heat and mass transfers, the extent of thermal reactions within the sponge cake and repeatability of the baking operation were all characterized by experimental measurements. Some of the main operating variables were monitored in the cake (core and surface temperatures, moisture content, levels of chemical reactants and products) and others in the baking atmosphere (temperature, humidity and concentrations of volatile compounds). Specific non-disruptive sampling devices were designed to extract data from cakes and the oven atmosphere in order to follow the kinetics of thermal reactions during the baking operation. Three phases could be identified during baking, corresponding to the relative importance of conductive and evaporative internal heat transfer regimes and to macroscopic changes in the cake structure with formation of a crust. The progress of thermal reactions was monitored with satisfactory precision in both the cake and the baking vapors: relative standard deviations of 2% and 8.7% were obtained respectively for the water content and hydroxymethylfurfural (HMF) content of three replicates during a baking operation.     

Effect of Flour Type and Baking Temperature on Cake Dynamic Height Profile Measurements During Baking

A dynamic height profile method using digital imaging of cakes at 2 min intervals during baking was used to analyze changes in volume during baking for cakes made with three different flour types (plain flour, heat-treated cake flour, and strong white flour) and baked at three different temperatures (175°C, 190°C, and 205°C). The cakes made from the different flours showed, with some exceptions, a similar trend in the shape and development of the top contour during baking. In the first 4–6 min of baking, there was relatively little expansion followed by a period of rapid expansion to the maximum volume and a period of contraction up to the end of baking. For the three flour types, volume peaked at 16–17 min for the medium and high baking temperatures and at 20 min for the low baking temperature. Cakes made from heat-treated cake flour and strong white flour baked at low and high temperatures produced cakes where the center of the cake was lower than the surrounding pins resulting in a final undesirable dimpled cake contour. A higher baking temperature caused the cake to rise more rapidly. Baking at high temperature produced cakes which shrank the most (P < 0.001) during cooling. Among all combinations of flour type and different temperature treatments, cake made from heat-treated cake flour baked at the middle temperature produced the best final cake in terms of a final dome-shape contour, an appreciable volume during baking, less volume shrinkage during baking, and maximum cross-sectional area of the half cake after 1 h cooling.