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◦C 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 μm) were not a great interference in this case

Structural characteristics of chocolates

PEREGO, PATRIZIA;CONVERTI, ATTILIO;
2012-01-01

Abstract

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◦C 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 μm) were not a great interference in this case
2012
9783905609493
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11567/377782
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