RESUMO
In the present work it was analyzed the water mobility by characterizing the thermo-gravimetric analysis of the cookie dough with the incorporation of dietary fibers. The fibers analyzed were: inulin (IN), oat fiber (OF), high amylose maize starch (RSII) and phosphate distarch-phosphate (RSIV). Four tests were performed: thermo-gravimetric analysis (TGA), pasting profile analysis using water and a solution of 50% sucrose as a solvent, and the study of the ultrastructure of the flour and fiber by SEM and particle size distribution. Changes in the thermo-gravimetric profile were explained by the pasting profile of composites and the ultrastructure of the wheat flour and fibers. OF and IN incorporation changed substantially dough water loss profile and rate. The addition of fibers produced a decrease in the starch pasting profile and inulin showed the highest reduction since less water was available for the hydration of wheat flour starch granules.
Assuntos
Fibras na Dieta , Água/química , Farinha , Amido , Temperatura , TriticumRESUMO
The effect of fiber addition on the distribution and mobility of protons in biscuits is studied by using low resolution time domain nuclear magnetic resonance (TD-NMR). The proportion of flour is reduced in order to incorporate inulin and oat fiber. NMR temperature dependent experiments are carried out in order to gain insight on the processes occurring in biscuit baking. Proton populations were identified measuring spin-spin relaxation times (T2). The major change in the relaxation profiles upon incorporation of fibers corresponds to mobile water molecules, which appear to be related to dough spreading behavior and biscuit quality. Biscuit samples baked in a commercial oven were studied by two dimensional spin-lattice/spin-spin (T1-T2) relaxation maps. The T1/T2 ratio is used as an indicator of the population mobility, where changes in the mobility of water in contact with flour components as starch, proteins and pentosans are observed.
Assuntos
Fibras na Dieta/análise , Farinha/análise , Espectroscopia de Ressonância Magnética/métodos , Prótons , Avena/química , Proteínas Alimentares/química , Tecnologia de Alimentos , Inulina/química , Amido/química , Água/químicaRESUMO
In this work we evaluated the efficacy and safety of a bread formulation containing chitosan in dyslipidemic type 2 diabetic subjects. For this purpose a total of 18 patients were allowed to incorporate to their habitual diets 120 g/day of bread containing 2% (wt/wt) chitosan (chitosan group, n= 9) or standard bread (control group, n= 9). Before the study and after 12 weeks on the modified diet, the following parameters were evaluated: body weight, plasma cholesterol, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, triglyceride, and hemoglobin A(1c) (HbA(1c)). Compared with the control group, the patients receiving chitosan-containing bread decreased their mean levels of LDL-cholesterol and significantly increased their mean levels of HDL-cholesterol at the end of the study. There were no significant differences in the body weight, serum triglyceride, and HbA(1c). These results suggest that chitosan incorporated into bread formulations could improve the lipoprotein balance similar to typical biliary salts trappers, increasing the HDL- and lowering the LDL-cholesterol, without changing the triglyceride levels. These results warrant further studies over a longer period of time to evaluate if a persistent improvement in levels of lipoproteins can be attained with this strategy.
Assuntos
Pão , Quitina/análogos & derivados , Quitina/administração & dosagem , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Diabetes Mellitus Tipo 2/dietoterapia , Hiperlipidemias/dietoterapia , Glicemia/metabolismo , Peso Corporal/efeitos dos fármacos , Quitina/efeitos adversos , Quitosana , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/complicações , Aditivos Alimentares/farmacologia , Aditivos Alimentares/uso terapêutico , Hemoglobinas Glicadas/análise , Humanos , Hiperlipidemias/sangue , Hiperlipidemias/complicações , Resultado do Tratamento , Triglicerídeos/sangueRESUMO
The effects of freezing and storage in frozen conditions on bread quality, crumb properties, and aggregative behavior of glutenins were analyzed. The effect of different additives on bread quality was also studied. The results obtained showed that freezing and storage at -18 degrees C decreased the bread quality. Samples stored in frozen conditions supplemented with diacetyl-tartaric acid ester of monoglycerides, gluten, and guar gum produced breads of greater volume and more open crumb structure than those prepared with the base formulation (without additives). All additives analyzed increased the proof time. Crumb firmness increased with dough frozen storage and bread aging time at 4 degrees C. A decrease in the amount of glutenin subunits of high molecular mass was observed by electrophoresis analysis of the SDS-soluble proteins aggregates extracted from the frozen dough. This result suggested that the protein matrix of bread underwent depolymerization during storage in frozen conditions.