Infrared Microwave Combination Research Articles

Rheological and quality properties of tiger nut containing biscuit dough baked in IR-MW combination oven.

The effects of replacing part of the rice flour (RF) with tiger nut flour (TNF) were studied in gluten-free biscuits. A control biscuit dough containing RF only and 5 formulations containing 10, 20, 30, 40, and 50 % tiger nut flour on a flour basis (10TNF, 20TNF, 30TNF, 40TNF, and 50TNF) were prepared. The rheological and quality properties of biscuits baked both in conventional and infrared-microwave combination (IR-MW) ovens were determined. The rheological results showed that as the TNF ratio increased, G', G" and ƞ* decreased due to the high oil and dietary fiber content of the TNF. Texture analysis results showed that control dough and biscuits showed harder texture because of the damaged starch content of RF. Damaged starch also affected the spread ratio of the biscuits adversely. Weight loss of the biscuits baked in the IR-MW oven was higher than the ones baked in the conventional oven since higher inside pressure occurred in the dough. The color of the conventional baked biscuits was darker than IR-MW baked ones due to the greater extent of Maillard Browning. As the TNF ratio increased, darker biscuits were obtained since TNF has a high amount of sugar, and also its natural color is brown. Given the excellent nutritional and product quality impacts of TNF, it would be appropriate to use it as a raw material substitute in gluten-free biscuits. Furthermore, IR-MW baking was shown to be an appropriate method for biscuit quality when compared to conventional baking. This article is protected by copyright. All rights reserved.

Gluten‐free bakery and pasta products: prevalence and quality improvement

SummaryAn increasing demand of gluten‐free (GF) products is caused by a growing number of diagnosed coeliacs and a consumption trend to eliminate allergenic proteins from diet. Driven by the rapidly growing market, comprehensive understanding of GF products is necessary. The purpose of this review was to concisely present an overview of various approaches to improve physicochemical and sensory qualities of GF bread, cake/muffin and pasta/noodle products. Some novel techniques used in GF products were discussed in this review. These techniques included the use of different alternative flours (including GF cereals, pseudo‐cereals, legume flours, fruit and vegetable powders and seafood powders), functional ingredients (including hydrocolloids and gums, emulsifiers, proteins and dietary fibres) and optimal processing (pretreated flour, infrared–microwave combination baking and extrusion cooking). Some recent novel technologies including transgenesis, enzymolysis and fermentation that have been used on GF products were also discussed.

Effect of Gum Type and Flaxseed Concentration on Quality of Gluten-Free Breads Made from Frozen Dough Baked in Infrared-Microwave Combination Oven

As prevalence of celiac disease increases, the demand for gluten-free products also increases. Researchers are still trying to improve gluten-free bread quality and shelf life to reach the quality of wheat bread. In this study, the aim was to obtain gluten-free breads made from frozen dough with acceptable specific volume, crumb firmness, and color and to investigate the effects of gum type and flaxseed concentration on the quality of gluten-free breads. Three different gum types (guar gum, xanthan gum, locust bean gum) were used. Gums were added to the formulation at 1 % level. Flaxseed was also added to the formulation at different concentrations (0, 2.5, and 5 %). After frozen storage at −20 °C for 10 days, frozen samples were thawed at +4 °C. Thawed samples were then fermented and baked in infrared-microwave (IR-MW) combination oven. The quality parameters (weight loss, specific volume, hardness, and color) of gluten-free breads were determined. In addition to the measurement of hardness of fresh samples, hardness of staled samples during the 72-h storage was also determined to investigate the effects of different formulations in retarding the staling of gluten-free breads. When the effects of gums and flaxseed concentration on the quality of breads were considered, the quality of gluten-free breads formulated with guar gum-5 % flaxseed was found to be better (with lower hardness, higher specific volume, and better color) than the other samples. The results obtained during the 72-h storage also demonstrated that gluten-free breads formulated with guar gum-5 % flaxseed had the lowest hardness values.

Optimization of formulation of soy-cakes baked in infrared-microwave combination oven by response surface methodology.

The aim of present work is to optimize the formulation of a functional cake (soy-cake) to be baked in infrared-microwave combination oven. For this optimization process response surface methodology was utilized. It was also aimed to optimize the processing conditions of the combination baking. The independent variables were the baking time (8, 9, 10min), the soy flour concentration (30, 40, 50%) and the DATEM (diacetyltartaric acid esters of monoglycerides) concentration (0.4, 0.6 and 0.8%). The quality parameters that were examined in the study were specific volume, weight loss, total color change and firmness of the cake samples. The results were analyzed by multiple regression; and the significant linear, quadratic, and interaction terms were used in the second order mathematical model. The optimum baking time, soy-flour concentration and DATEM concentration were found as 9.5min, 30 and 0.72%, respectively. The corresponding responses of the optimum points were almost comparable with those of conventionally baked soy-cakes. So it may be declared that it is possible to produce high quality soy cakes in a very short time by using infrared-microwave combination oven.

Infrared Assisted Microwave Cooking of Atlantic Salmon (Salmo salar)

In this study, infrared–microwave combination heating was used to cook Atlantic salmon (Salmo salar) samples, and the optimum cooking conditions in infrared-microwave combination oven were determined. Response Surface Methodology (RSM) was used to identify optimum values of cooking time (4, 5, 6 minutes), halogen lamp power level (80%, 90%, 100%), and microwave power level (20%, 30%, 40%) regarding of four responses – internal temperature, cooking yield, L* and b* values. A three-factors modified Box–Behnken design was carried out to estimate the model coefficients. The derived secondorder polynomial models sufficiently represented the experimental data. Optimum conditions were predicted as 5 minutes of cooking time, 100% halogen lamp power level, and 30% microwave power level by using the target values obtained in conventional cooking (at 200°C for 15 minutes). This study showed that infrared assisted microwave cooking is a promising alternative method for fish and other seafoods with reduced cooking time and color formation on the surface of salmon.

A Study on Staling Characteristics of Gluten-Free Breads Prepared with Chestnut and Rice Flours

The effects of chestnut flour and a xanthan–guar gum blend–DATEM mixture on staling of gluten-free rice breads baked in conventional and infrared–microwave combination ovens were studied. Staling properties of the bread were assessed using mechanical compression (TA), differential scanning calorimetry, X-ray diffraction, and fourier transform infrared spectroscopy (FT-IR). Hardness, moisture loss, and retrogradation enthalpy values for all bread samples increased significantly during storage. FT-IR spectra showed that the integrated area of peaks around 1,041 and 1,150 cm−1 wave lengths, which are related to the structure of starch retrogradation, increased with storage time. The X-ray diffractograms of aged breads indicated a B-type structure with the appearance of peaks at around 17°, 19.5°, and 22°. An additional peak at 24° was observed in breads stored for longer periods. Higher values of hardness and lower moisture contents were obtained for breads baked in an infrared–microwave combination oven, but the use of infrared–microwave combination oven did not result in excessive hardness after storage. Retrogradation enthalpies and total crystallinity values of breads did not show significant differences with baking type.The replacement of rice flour with chestnut flour and addition of xanthan–guar gum blend–DATEM mixture in formulations significantly delayed staling of gluten-free breads by decreasing moisture loss, hardness, retrogradation enthalpy, and total mass crystallinity.

Image Analysis of Gluten-free Breads Prepared with Chestnut and Rice Flour and Baked in Different Ovens

In this study, the effects of chestnut flour and xanthan–guar gum blend–emulsifier DATEM mixture addition on macro- and microstructure of rice breads baked in conventional and infrared–microwave combination ovens were investigated by using the images obtained by a scanner and scanning electron microscopy (SEM). Pore area fraction, pore size distribution, and roundness values of pores were determined. The highest pore area fraction values were obtained in breads prepared by replacement of 46 % of rice flour with chestnut flour containing xanthan–guar gum blend–DATEM mixture and baked in an infrared–microwave combination oven. On the other hand, rice breads containing no additives or chestnut flour had the lowest pore area fraction values. Infrared–microwave combination baking increased both pore area fraction values and total number of pores. Infrared–microwave combination baking caused approximately 23–28 % increase in number of the small pores (0–5 mm2) in rice breads and 71 % increase in number of the large pores (>10 mm2) in chestnut–rice breads. The fiber content and larger starch granules of chestnut flour contributed towards the stabilization of gas bubbles resulting in better crumb structure. More homogenous pore distributions were observed when additives and an infrared–microwave combination oven were used. When microstructure of gluten-free breads was investigated, it was seen that starch granules in chestnut–rice breads baked in an infrared–microwave combination oven did not disintegrate completely.

Quality of Gluten-Free Bread Formulations Baked in Different Ovens

The objective of this study was to determine the effects of different tigernut flour/rice flour ratios (0:100, 5:95, 10:90, 15:85, 20:80, and 25:75) on quality of gluten-free bread formulations baked in infrared–microwave combination and conventional ovens. The degrees of the starch gelatinization of breads baked in different ovens were also compared. Conventionally baked breads prepared with tigernut flour/rice flour ratio of 10:90 and the infrared–microwave combination-baked breads prepared with tigernut/rice flour ratio of 20:80 had the most acceptable firmness and specific volume values. These breads had also similar color. Tigernut flour had significantly higher gelatinization temperatures and lower gelatinization enthalpy (ΔHg) values than rice flour (p ≤ 0.05). As rice flour was replaced with tigernut flour, lower ΔHg values were observed in dough samples. Breads baked in both conventional and combination oven had sufficient starch gelatinization degrees ranging from 91% to 94% and from 84% to 85%, respectively.

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

SummaryThe 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.

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%).

The effects of gums on macro and micro-structure of breads baked in different ovens

In this study, the effects of gums on macro and micro-structure of breads baked in different ovens (infrared (IR)-microwave combination and conventional) were investigated by the help of image and SEM analysis, respectively. The gums used were xanthan, guar, κ-carrageenan and xanthan-guar blend. The gums were added to the formulation at 0.5% concentration. As a control, no gum added formulations were used. Results of Image analysis demonstrated that xanthan-guar gum blend addition improved bread quality with increasing pore area fractions. It was seen that about 75% of the pores of control breads baked in infrared-microwave combination oven and about 63% of the pores of control breads baked in conventional oven had diameters of above 1000 μm. According to SEM analysis, pores in control breads baked in conventional oven were found to be smaller, and had spherical, oval-like shape as compared to the ones baked in IR-microwave combination oven. Moreover, more homogeneous closed-cell structure was observed for conventionally baked control breads. The pores of breads baked in IR-microwave combination oven were so close to each other which resulted in coalescence of the gas cells to form channels, then the pores were no longer spherical. The starch granules in conventionally baked breads were more distorted and seen as a continuous sheet of gelatinized starch. On the other hand, granular residues and continuous starch structure was observed together in IR-microwave combination heating.

Investigation of physicochemical properties of breads baked in microwave and infrared-microwave combination ovens during storage

Staling of breads baked in different ovens (microwave, infrared-microwave combination and conventional) was investigated with the help of mechanical (compression measurements), physicochemical (DSC, X-ray, FTIR) and rheological (RVA) methods. The effect of xanthan-guar gum blend addition on bread staling was also studied. Xanthan-guar gum blend at 0.5% concentration was used in bread formulation. The gums were mixed at equal concentrations to obtain the blend. After baking, the staling parameters of breads were monitored over 5 days storage. During storage, it was seen that hardness, retrogradation enthalpies, setback viscosity, crystallinity values, and FTIR outputs related to starch retrogradation of bread samples increased, whereas FTIR outputs related to moisture content of samples decreased significantly with time. The hardness, retrogradation enthalpy, setback viscosity, and crystallinity values of microwave-baked samples were found to be highest among other heating modes. Using IR-microwave combination heating made it possible to produce breads with similar staling degrees as conventionally baked ones in terms of retrogradation enthalpy and FTIR outputs related to starch retrogradation. Addition of xanthan-guar gum blend decreased hardness, retrogradation enthalpy and total mass crystallinity values of bread samples showing that staling was delayed.

Optimization of Baking of Rice Cakes in Infrared–Microwave Combination Oven by Response Surface Methodology

In this study, response surface methodology was used to design gluten-free cakes made from rice flour to be baked in infrared-microwave combination oven. Two types of cake formulations containing different types of gums were used in the experiments, which were xanthan gum and xanthan–guar gum blend. The independent variables were emulsifier content (0, 3, and 6% of flour weight), upper halogen lamp power (50, 60, and 70%), and baking time (7, 7.5, and 8 min). Specific volume, surface color change, firmness and weight loss of the cakes were determined for optimization. Cakes formulated with xanthan gum had better quality characteristics than cakes containing xanthan–guar gum blend. Cakes formulated with xanthan gum and 5.28% emulsifier and baked using 60% halogen lamp power for 7 min had the most acceptable quality.

Investigation of Dielectric Properties of Different Cake Formulations during Microwave and Infrared–Microwave Combination Baking

Dielectric properties can be used to understand the behavior of food materials during microwave processing. Dielectric properties influence the level of interaction between food and high frequency electromagnetic energy. Dielectric properties are, therefore, important in the design of foods intended for microwave preparation. In this study, it was aimed to determine the variation of dielectric properties of different cake formulations during baking in microwave and infrared-microwave combination oven. In addition, the effects of formulation and temperature on dielectric properties of cake batter were examined. Dielectric constant and loss factor of cake samples were shown to be dependent on formulation, baking time, and temperature. The increase in baking time and temperature decreased dielectric constant and loss factor of all formulations. Fat content was shown to increase dielectric constant and loss factor of cakes.

A study on the effects of different gums on dielectric properties and quality of breads baked in infrared-microwave combination oven

In this study, the effects of different gums on dielectric properties of doughs and breads baked in infrared-microwave combination oven were investigated. In addition, the quality parameters of breads formulated with different gums baked in infrared-microwave combination oven were determined. The gums used were xanthan, guar, xanthan-guar blend and κ-carrageenan. The gums were added to the formulation at 0.5% concentration. The dielectric properties and quality parameters of breads baked in infrared-microwave combination oven were found to be dependent on gum type. κ-carrageenan resulted in undesirable final bread quality, while xanthan-guar blend addition improved bread quality (high specific volume and porosity, low hardness values). The dielectric properties of bread samples formulated with κ-carrageenan were found to be the highest among the other gum types.

The Effect of Different Formulations on Physical Properties of Cakes Baked with Microwave and Near Infrared-Microwave Combinations

The aim of this study was to determine the effect of different formulations on color and textural characteristics of different cakes during baking in microwave and near infrared-microwave combination ovens. For comparison, cakes were also baked in conventional ovens.Color and hardness for both types of baking schemes were found to be dependent on formulation. Cakes containing Simplesse™ a fat replacer consisting mostly of whey protein, baked in microwave and near infrared-microwave combination ovens were found to be the firmest cakes.

Microwave, infrared and infrared-microwave combination baking of cakes

The objective of the study was to compare the quality of cakes during baking in microwave, infrared (IR) and IR-microwave combination ovens. Quality parameters evaluated were weight loss, specific volume, firmness and colour of cakes. As control, conventionally baked cakes were used. Cakes baked in a microwave oven had the lowest quality. It was possible to achieve surface colour formation in cakes by IR and IR-microwave combination baking. IR-microwave combination baking reduced weight loss and firmness while it increased the volume of microwave baked breads. Halogen lamp-microwave combination oven produced cakes having similar firmness and colour values with conventionally baked ones. The best conditions for baking of cakes in IR-microwave combination oven was 5 min at 70% halogen lamp and at 50% microwave power levels. When an IR-microwave combination oven was used at this condition conventional baking time of cakes was reduced by about 75%.