Master of Science / Department of Food Science / Fadi Aramouni / Despite the expansion of the gluten-free (GF) food market, some GF food items are still characterized by an overall mediocre quality. The effects of different types of egg ingredients (fresh, whites, dried) and carob germ flour (CGF) as well as par-baking technology on the quality of dough-based gluten-free sorghum dinner rolls were evaluated. Gluten-free rolls containing 30% of fresh shell eggs or equivalent of egg products and 10% of CGF on a flour basis were evaluated against a control (no egg, no CGF). The feasibility of partial baking of rolls was studied on control as well as fresh eggs and carob germ flour formulas during 5 baking times (0, 8, 10, 12 and 18 minutes). Breads were evaluated for crumb and crust color, specific volume, cell profile, Texture Profile Analysis (TPA) and consumer acceptability. Results showed that rolls containing egg ingredients had higher specific volumes than control (p<0.05) with an increase from 1.45 cm[superscript]3/g to 1.96 cm[superscript]3/g. Carob germ flour did not have a significant effect on specific volume. Eggs also improved cell elongation and produced significantly darker crust (p<0.05). CGF did not appear to have an effect on cell elongation but increased average cell number when combined with egg ingredients, and greatly impacted rolls texture. The combination of fresh eggs or egg whites with CGF reduced significantly (p<0.05) crumb hardness from 2,074 to 1,404g and 1,468g of force respectively. Par-baked dinner rolls displayed similar color, volume, cell profile and texture trends to conventionally baked rolls. Sensory study revealed that acceptability, organoleptic characteristics and willingness to buy of par-baked dinner rolls could be similar to that of conventional wheat products. This research proved that the addition of eggs and CGF to a GF rolls formulation resulted in better overall quality of the product. Moreover, par-baking of the rolls showed great potential to provide safe, convenient and acceptable GF foods to celiac individuals.

Master of Science / Department of Grain Science and Industry / Rebecca Miller / Sorghum is a vital cereal crop grown in many regions around the world. Tolerance to harsh climates and low moisture conditions are unique traits making sorghum an economical choice in an era of global water scarcity. In recent years, sorghum has gained greater recognition as a gluten-free grain and is a safe alternative for individuals suffering from gluten sensitivities or celiac disease. Still, the lack of gluten proteins does not allow sorghum to form a viscoelastic dough. In this study reducing agents were added to improve functional properties of sorghum kafirins for bread baking. Study objectives were to determine the effect of reducing agents on protein body structure of sorghum kafirins, investigate the influence on the sorghum batter consistency, and evaluate the effects on the physical characteristics of sorghum bread. Protein analysis, accomplished using RP-HPLC, showed reducing agents, L-cysteine and sodium metabisulfite, reduced protein structure; increasing RP-HPLC total peak area up to 747% and 681%, respectively. Batter consistency was obtained using a RVA. Treatments of L-cysteine (2.5% fwb) expressed increased RVA peak viscosity and decreased final viscosity. Samples treated with sodium metabisulfite (500 ppm fwb) had increased peak viscosity, holding strength and final viscosity. Yeast activity of batter treated with ≥3000 ppm (fwb) sodium metabisulfite caused volume loss of 95% yet at 500 ppm (fwb) sodium metabisulfite did not have an effect. Batter with 2.5% (fwb) L-cysteine experienced reduced yeast activity after 20 min. Sorghum bread characteristics were altered. Loaf volume and crumb grain characteristics of bread produced using sodium metabisulfite (500 ppm) were equal to that of the control, while initial texture and staling were improved. The addition of L-cysteine (2.5% fwb) to breads lowered loaf volume but produced softer initial crumb texture and improved in-vitro protein digestibility by 18.8%.

The main objective of the study was to determine the effects of enzymes on quality of breads baked in halogen lamp-microwave combination, microwave and conventional oven. It was also aimed to determine the optimum processing conditions in these ovens. In the first part of the study, as independent variables, baking time, baking temperature for conventional oven / microwave power for microwave oven and microwave power and halogen power for combination oven was used. Weight loss, specific volume, firmness and color of the breads were measured during the study. The optimum baking conditions were determined as 13 min at 200&deg / C in conventional oven, 0.75 min at 100% power in microwave oven, 10 min at 60% power in halogen lamp oven, and 3 min at 30% microwave power and 70% halogen lamp power in halogen lamp-microwave combination oven. In the case of combination oven, specific volume and color values of breads were comparable with the conventionally baked breads but weight loss and firmness of them were still higher. The effects of different enzymes (&amp / #945 / -amylase, xylanase, lipase &amp / protease) were studied to reduce the quality problems of breads baked in microwave and halogen lamp-microwave combination oven. The optimum baking conditions determined for each type of oven in the first part of the study were used in the investigation of the functions of enzymes on bread quality during baking and staling. As a control, no enzyme added breads baked at 200&deg / C for 13 min in conventional oven were used. All the enzymes were found to be effective in reducing initial firmness and increasing specific volume of breads baked in microwave and halogen lamp-microwave combination ovens. However, in conventional baking, the effects of enzymes on crumb firmness were seen mostly during storage. The usage of enzyme protease in the bread formulation resulted in breads with higher volume and darker color in all of the ovens. All of the enzymes were found to be effective to retard the staling of breads baked in conventional, microwave and halogen lamp-microwave combination ovens.

En av Glimek AB:s mest förekommande maskiner är SD-180 som används för degavvägning. Den finns i flera olika varianter. Den enklaste har enbart start- och stoppknapp och en potentiometer för att ställa hastigheten och en mer avancerad variant har en operatörspanel där olika möjligheter till inställningar finns. Konstruktionen på denna maskin hade inte uppdaterats på många år och behövde en uppdatering av användargränssnitt, programvara och elkonstruktion. Arbetet har framförallt koncentrerat sig på användargränssnittet till panelen. En del av arbetet var att undersöka om det var möjligt att utesluta PLC ur konstruktionen och använda en mer avancerad programmerbar frekvensomformare. Eftersom det blev problem med lanseringen av programvara till frekvensomformaren och enbart en mindre bra fungerande demoversion fanns tillgänglig så var detta tyvärr inte möjligt. I arbetet har olika varianter på operatörspaneler utretts. Exempel på flödesdiagram till PLC har också gjorts. / One of Glimek AB's most common machines is the dough divider, SD-180. It is available in many different variants. The simplest has only a start- and stop button and a potentiometer to set the speed. A more advanced version has an operator panel with various options. The design of this machine had not been updated in many years and needed an update of the user interface, software and electrical construction. The thesis has mainly concentrated on the human machine interface. A part of the work was to investigate whether it was possible to exclude the PLC from the design and use a more powerful and programmable frequency inverter.Unfortunately problems arose with the release of the software for the frequency converter. Only a demo version of the software where available and it was not possible to this study because of that. Different variants of human machine interface have been investigated. An example flowchart diagram to the PLC has also been made.

Increasing diagnosis and awareness of celiac disease and gluten intolerance has created a need for developing improved quality gluten-free sandwich breads. Sorghum is a naturally gluten-free grain with ideal baking qualities that is underutilized in the gluten-free baking industry. Research is needed on developing gluten-free breads utilizing sorghum flour that could be used in future research and commercial production. Three objectives were tested. Objectives evaluated feasibility of using egg white foam with leavening agents in yeast-free bread, optimum mixing time in a laboratory control bread utilizing sorghum flour, and maximizing the amount of sorghum flour that could be used in the control formulation. Four comparisons were tested for yeast-free breads and 5 were compared for yeast breads. Volume, hardness, and color were measured using 15 replications. Environmental Scanning Electron Microscopy (ESEM) was performed on selected treatments to evaluate crumb structure. Utilizing egg white foam for gluten-free breads produced acceptable volume, color, crumb structure and hardness compared to commercial gluten-free controls. Using egg white foam eliminates proofing time with increased production speed. Increasing mixing time in gluten-free yeast breads significantly (P<0.05) improved specific volume and overall loaf volume without negatively affecting crumb hardness in 10 and 15 minute mixing treatments. Crumb structure was significantly improved between 5 and 15 minute treatments. Evaluation with ESEM showed reduced clumping of ingredients in the crumb and thinner air cell walls. Specific volume and loaf volume were significantly (P<0.05) higher in 15 minute mixing (2.13 cm^3/g; 1845 cm^3) versus the commercial comparison (2.00 cm^3/g; 923 cm^3). Optimum mixing for yeast bread was 15 minutes and optimum percentage of sorghum used in the flour blend was 60 percent. Increasing the use of commodity grade gluten-free decorticated white sorghum flour will reduce cost of specialty milled ingredients. In future studies mixing for 15 minutes using the laboratory yeast bread formulation containing 60 percent sorghum should be used as the research control as it provided consistent optimum results.

The main objective was to determine the variation of physical properties of different cake formulations during baking in microwave and infrared-microwave combination ovens. In the first part of the study, rheological and dielectric properties of cake batter with different formulations were determined. Different concentrations of fat and different types of emulsifier and fat replacer were used. The variation of formulation had a significant effect on the apparent viscosity of the cake batter. Cake batter was found to show shear thinning and time independent behaviour for all formulations. Dielectric properties of cake batter were dependent on formulation, frequency and temperature. In the second part of the study, physical properties (dielectric properties, volume, texture, color and porosity) of cakes baked in microwave and infrared-microwave combination oven were determined. In addition, starch gelatinization during baking was investigated. For comparison, cakes were also baked in conventional oven. Formulation and baking time were found to affect physical properties and gelatinization degree of cakes. Addition of fat to the formulation was found to increase the dielectric properties and gelatinization degree of microwave and infrared-microwave combination baked cakes. For both microwave and combination baking, cake samples with SimplesseTM had the highest volume but the firmest texture. Addition of maltodextrin resulted in a more uniform structure for infrared-microwave combination baking. There was insufficient gelatinization in microwave baked cakes ranging from 70 to 78% depending on fat content. The gelatinization degree ranged from 88 to 93% in conventionally baked cakes. Combining infrared with microwaves increased gelatinization degree (80-90%).

The objective of this study was to determine the effects of different gums and their combination on quality and staling of breads baked in different ovens. In the first part of the study, the effects of gums (xanthan, guar, k-carrageenan, hydroxypropyl methylcellulose, locust bean gum and their blends) on quality of breads baked in infrared-microwave combination and conventional ovens were investigated. In addition, macro and micro-structure, dielectric and thermal properties and acrylamide content of breads were studied. Xanthan-guar blend addition improved bread quality with increasing specific volume and porosity values and decreasing hardness values of samples. More homogeneous closed-cell structure for conventionally baked control breads and channel formed cell structure for breads baked in infraredmicrowave combination oven were observed. Dielectric properties of breads were found to be a function of gum type. No acrylamide was formed in microwave baked breads. Breads baked in infrared-microwave combination oven had similar acrylamide content with conventionally baked ones. The second part of the study focused on staling. The hardness, retrogradation enthalpy, set back viscosity, FTIR outputs and crystallinity values of microwave-baked samples were found to be the highest. Infraredmicrowave combination heating made it possible to produce breads with similar staling degrees as conventionally baked ones and reduced the conventional baking time of breads by about 39%. Addition of xanthan-guar blend decreased hardness, retrogradation enthalpy and crystallinity values of breads. According to hardness data, in the presence of xanthan-guar blend staling of breads baked in all types of ovens was delayed for 1 day.

The main objective of this study was to design gluten free rice cakes containing different gums and an emulsifier for baking in infrared (IR)-microwave combination oven. In the first part of the study, the effects of different gums (xanthan, guar, xanthan-guar blend, &amp / #954 / -carrageenan, locust bean, hydroxypropyl methylcellulose (HPMC) and xanthan-&amp / #954 / -carrageenan blend) and emulsifier blend (PurawaveTM) on physical properties of cake batters were investigated. In the second part of the study, weight loss, specific volume and texture of the cakes baked in different ovens were determined. Macro and micro-structures of the cakes were investigated both qualitatively and quantitatively by using image analysis and Scanning Electron Microscopy (SEM). In the last part of the study, Response Surface Methodology (RSM) was used to optimize IR-microwave baking conditions and formulation of the cakes. Power law and Casson models were suitable to explain the rheological properties. Xanthan and xanthan-guar gum blends resulted in higher apparent viscosities as compared to other gums. Gum types affected the dielectric properties and gelatinization enthalpies of cake batter. Emulsifier addition increased the volume and porosity but decreased the firmness of the cakes baked in IR-microwave combination oven. More porous cakes were obtained when xanthan and xanthan-guar gum blend were used. Baking method was found to be important in affecting porosity, pore size distribution and microstructure of the cakes. The highest quality gluten-free rice cakes were obtained when the formulation contained xanthan gum and 5.38% emulsifier and baked using 40% microwave power, 60% halogen lamp power for 7 min in IR-microwave combination oven. In addition, baking time was reduced by 76.7% as compared to conventional baking.

The main objective of this study was to optimize processing conditions during halogen lamp-microwave combination baking of cake by using Response Surface Methodology. It was also aimed to compare quality of products baked in microwave-halogen lamp combination oven, halogen lamp oven, microwave oven and conventional oven. In the first part of the study, as independent variables, baking time for conventional oven / microwave power and baking time for microwave oven / halogen lamp power and baking time for halogen lamp oven and microwave power, halogen lamp power and baking time for halogen lamp-microwave combination oven were used. Weight loss, specific volume, firmness and color of the cakes were measured during the study. Cakes baked in conventional oven at 175&deg / C for 24 minutes were determined as the control cakes. Weight loss of cakes increased with increasing independent variables for all oven types. Specific volume and firmness of cakes increased with increasing microwave power, but decreased with upper halogen lamp power. Color formation was achieved in the combination baking but not as much as in the conventional baking. Response Surface Methodology was used to optimize the baking conditions in the second part of the study. Upper and lower halogen lamp powers, microwave power and baking time were used as independent variables. Optimum processing conditions were found as 60% for upper halogen lamp power, 70% for lower halogen lamp power, 30% for microwave power and 5 minutes for baking time. Cakes baked at optimum baking conditions had comparable quality with conventionally baked ones, except color. In short, by the usage of halogen lamp-microwave combination oven it was possible to obtain high quality cakes by reducing of conventional baking time about 79%.

Examensarbete.