Structural characteristics of chocolates

Chocolate is a suspension of solid particles (sugar, cocoa solids and milk solids) in a continuous fat phase. Chocolate manufacturing is complex and requires a combination of several ingredients and technological operations to achieve the desired rheological, textural and melting qualities. Cocoa nibs contribute which around 30 % of the final chocolate fat content. Particle size distribution is a key determinant of the flow (rheological) properties in chocolates with a direct influence on sensory perception. Quality in finished chocolates is highly dependent on inherent size distribution of solid particles, composition of fat phase and emulsifiers. The rheological parameters (yield stress and plastic viscosity) of chocolates is usually quantified during processing, mainly through Casson model. The aim of this study was to evaluate structural chocolates characteristics made with different fat content and particles size by three steps test. The rheological behavior of the formulations was determined by a Haake MARS rheometer at 40\u25e6C with the test (CR) taken in three steps: (1) 0,00 1/s a 65,00 1/s, t = 180 s; (2) 65,00 1/s, t = 60 s; (3) 65,00 1/s a 0,00 1/s, t = 180 s. Fat content and quality as well particles size were determined. The chocolate samples were prepared using traditional process. The results of rheological studies showed the interference of fat content and particles size on the initial tension of the products. The sample with lower fat content and larger particle size showed higher yield stress and greater hysteresis area, with larger thixotropy, indicating the relationship of these parameters with the fat content and particle size. The viscosity has only a slight increase; this difference was not significant factor in practice, pointing out that both the applied variation of fat (36 - 42 %) as the particles size (18 - 22 \u3bcm) were not a great interference in this cas

Leavening bread dough

Dough of bread is prepared from mixture of flour wheat, water, salt and yeast. By contacting water and suffering mechanical kneading the flour gets properties, almost exclusively, to produce a cohesive dough and viscoelasticity, containing gluten-forming proteins. The mixing process through which the dough of bread is produced, is essential for its development after fermentation and the final quality of finished bread. Gluten is important to create an extensible framework implied in gas retention during fermentation. The Baker's yeast used in baking is Saccharomyces cerevisiae, whose most important function in bread-making is to leaven the dough during the baking process. Dough expansion results from yeast action in catabolizing glucose to alcohol and carbon dioxide