The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform

Simona Romani - One of the best experts on this subject based on the ideXlab platform.

  • Microstructural and rheological characteristics of dark, Milk and white Chocolate: A comparative study
    Journal of Food Engineering, 2016
    Co-Authors: Virginia Glicerina, Marco Dalla Rosa, Francis Balestra, Simona Romani
    Abstract:

    Three different Chocolate types: dark, Milk and white were characterized and compared for the microstructural and rheological (fundamental and empirical) characteristics. A light microscope coupled to an image analysis system was employed in order to evaluate the particle size, the network structure and the distance between particles of each matrix. Rheological parameters (yield stress, viscosity, thixotropy) were evaluated by using a stress-strain rheometer, while mechanical properties (consistency and cohesiveness) were analysed using a texture analyzer. The Power law, Casson and Windhab rheological models were used in order to better explain the rheological behaviour of Chocolate samples. Results showed that white Chocolate, with the highest amount of fat in formulation, had the smallest sized particles, the less aggregate structure and the lowest yield stress, viscosity and thixotropic values. Dark Chocolate samples instead presented the highest aggregate structure, with less void spaces between particles that involved the highest rheological parameter values. Milk Chocolate matrix exhibited intermediate microstructural and rheological characteristics compared to dark and white Chocolate ones.

  • Microstructural and Rheological Properties of White Chocolate During Processing
    Food and Bioprocess Technology, 2015
    Co-Authors: Virginia Glicerina, Francis Balestra, Marco Dalla Rosa, Simona Romani
    Abstract:

    The relationship between the microstructural and rheological properties of white Chocolate was studied during the main steps (mixing, pre-refining, refining, conching and tempering) of the manufacturing process. Laser light diffraction and light microscope techniques were used to study the particle size distribution (PSD) and the modifications of the network structure of the samples. Rheological parameters in terms of yield stress, apparent viscosity and thixotropy were evaluated by using a stress-strain controlled rheometer. The Casson and Windhab rheological models, which are widely used for dark and Milk Chocolate matrices, were used in order to explain better the rheological values obtained from the flow curves . Particle analysis revealed significant changes in the network structure during process. In particular, from the mixed sample to the refined one, a reduction in particle size was found; Sauter ( D[3.2]) and Feret diameters decreased, the former from 18.6 to 6.67 μm and the latter from 320 to 33 μm. Consequently, an increase in the matrix aggregation was observed. The white Chocolate samples obtained from the conching and tempering steps were characterized by the statistically lowest values of yield stress and apparent viscosity and by the weak structure. Moreover, the samples were well discriminated by both rheological models applied. [ABSTRACT FROM AUTHOR]

  • Effect of manufacturing process on the microstructural and rheological properties of Milk Chocolate
    2015
    Co-Authors: Virginia Glicerina, Francis Balestra, Dalla M. Rosa, Simona Romani
    Abstract:

    The effect of different process steps on microstructural, rheological and visual properties of Milk Chocolate was studied. Each process step affects the microstructural characteristics of Milk Chocolate, involving modifications on its macroscopic properties, such as rheological attributes. Milk Chocolate samples were obtained at each phase of the manufacture process: mixing, pre-refining, refining, conching and tempering. Microstructural properties (network structure and particle size) and rheological parameters (yield stress, apparent viscosity, thixotropy, G′ and G″) were evaluated by using respectively an environmental scanning electron microscope (ESEM), and a controlled strain-stress rheometer. Colorimetric analyses (L∗, h° and C∗) were also performed. ESEM analysis revealed important changes in the network structure during process, with a reduction in particle size and an increase in the voids between aggregates, from the mixing to the refining step. Moreover, an increase of all rheological analyzed parameters from mixed sample to the refined one was found. Samples obtained from the conching and tempering steps were characterized by the lowest statistically significantly values of all rheological parameters. This could be related to the changes in the structure aggregation evidenced by ESEM analysis. From colour results, the samples with the finest particles appeared lighter and more saturated than those with coarse particles

Genc Polat D. - One of the best experts on this subject based on the ideXlab platform.

  • Effects of polyols on the quality characteristics of sucrose-free Milk Chocolate produced in a ball mill
    RSC Advances, 2019
    Co-Authors: Homayouni Rad A., Rasouli Pirouzian H., Toker O.s., Genc Polat D.
    Abstract:

    Sucrose-free Milk Chocolates containing different types of bulk (isomalt, xylitol and maltitol) and high intensity (Stevia) sweeteners were produced by using a ball mill. The main quality characteristics of the formulated Chocolates were evaluated and compared with those of the conventional sample containing sucrose. The Casson model was the best fitting model for the rheological data. Casson viscosity and Casson yield stress were significantly affected by the type of bulking agent in Chocolates formulated with xylitol (p < 0.05). However xylitol notably improved the overall acceptability according to the sensory analysis results. Chocolates containing the sucrose replacers demonstrated lower Tonset values and higher enthalpy than the control sample. Sucrose-free Chocolates illustrated a higher degree of particle agglomeration. Bulk sweeteners meanwhile seem to have high potential for Milk Chocolate production with low calorie values by using the ball mill technique. Industrial applications: the production of sucrose-free Chocolates with conventional methods requires a lot of time and energy. Recently, using alternative methods for Chocolate production has been raising interest in many small industries. This study proposed a ball mill method for the preparation of sucrose-free Milk Chocolates with physiochemical properties almost ranging in the standard limit defined for Chocolate. Although using the ball mill method presents a more cost-effective technique for Chocolate production and provides shorter processing times for small Chocolate industries, it seems to be less efficient in evaporating moisture than the conventional processing. Challenges are still ahead for upgrading this alternative technique to be efficient in evaporating more moisture during operation ending in a high quality product

Nevzat Konar - One of the best experts on this subject based on the ideXlab platform.

  • Application of simplex lattice mixture design for optimization of sucrose-free Milk Chocolate produced in a ball mill
    Lwt - Food Science and Technology, 2019
    Co-Authors: Aziz Homayouni Rad, Omer Said Toker, Haniyeh Rasouli Pirouzian, Nevzat Konar
    Abstract:

    Abstract The aim of this study was to define optimal conditions by using Simplex lattice mixture design for the formulation of sucrose-free Chocolate produced in a ball mill. Milk Chocolate mass were made using three different polyols including maltitol, xylitol and isomalt along with Stevia as high potency sweetener. The influences of polyols mixtures as sucrose substitutes on rheological properties and main physical quality parameters were investigated. According to the results, the fitted models demonstrated a high coefficient of determination (≥93%). The optimization of the variables illustrated that utilizing 11.16% w/w maltitol, 8.9% w/w xylitol and 12.93% w/w isomalt produced the optimum Milk Chocolate with the highest desirability (1.00) without unwanted variations in the rheological and quality characteristics. Also the optimum formulation was produced to validate the optimum model. The sensory analysis of the optimized formulation satisfied the consumer demand.

  • rheological and physical properties of inulin containing Milk Chocolate prepared at different process conditions
    Cyta-journal of Food, 2014
    Co-Authors: Nevzat Konar, Bilge Ozhan, Nevzat Artik, Sevim Dalabasmaz, Ender Sinan Poyrazoglu
    Abstract:

    In the present study, the effects of inulin as a prebiotic substance at various levels (PSL) (0, 60, 90 and 120 g/kg) in Milk Chocolate, as well as the use of varying conching time (CT) (3.50, 4.0 and 4.50 h) and refining conditions (20.0, 25.0 and 28.0 µm as the mean particle size, D[4,3]) in the sample preparation process were examined with respect to changes in the physical (colour, hardness, water activity) and rheological properties of the samples. Specific surface area (SSA) and largest particle size (D90) values increased with increasing values of PSL; however, intended D[4,3] values were reached for all PSL values. CT, PSL and PSD (particle size distribution) had no significant effect on the brightness and chroma in the inulin-containing Milk Chocolate; however, it has been found that hardness, water activity, yield stress and viscosity produced significant changes (P < 0.01).

  • influence of conching temperature and some bulk sweeteners on physical and rheological properties of prebiotic Milk Chocolate containing inulin
    European Food Research and Technology, 2013
    Co-Authors: Nevzat Konar
    Abstract:

    Changes in food consumption habits and the developments set forth in the area of health and nutrition also change consumer expectations and demands. Sugar-free foodstuffs and products that have prebiotic activity are among the primary features of such expectations and demands. In the present study, the effects of substituting fine sugar with isomalt and maltitol in Milk Chocolate samples that contain inulin (9.0 % w/w), which is a substance with prebiotic activity, and the use of varying conching temperatures (CT) (50, 55 and 60 °C) in the sample preparation process on their physical (colour, hardness, water activity) and rheological properties were examined. Rheological data were obtained using the Herschel–Bulkley model which showed the best fitting for predicting rheology. It was determined that all properties included within the scope of the study are affected by the use of different bulk sweeteners or varying CT (P < 0.01). While colour properties, such as brightness (L*), hue angle (h°), water activity (aw) and rate index properties varied in a narrow range, it was determined that the yield stress and viscosity properties, which are among the important quality parameters of Chocolate and can have determining effects on sensory properties, manifest variations within a broad range, depending on the CT and the bulk sweeteners used. It was concluded that maltitol is a more suitable fine sugar substitute in Milk Chocolates containing inulin.

Virginia Glicerina - One of the best experts on this subject based on the ideXlab platform.

  • Microstructural and rheological characteristics of dark, Milk and white Chocolate: A comparative study
    Journal of Food Engineering, 2016
    Co-Authors: Virginia Glicerina, Marco Dalla Rosa, Francis Balestra, Simona Romani
    Abstract:

    Three different Chocolate types: dark, Milk and white were characterized and compared for the microstructural and rheological (fundamental and empirical) characteristics. A light microscope coupled to an image analysis system was employed in order to evaluate the particle size, the network structure and the distance between particles of each matrix. Rheological parameters (yield stress, viscosity, thixotropy) were evaluated by using a stress-strain rheometer, while mechanical properties (consistency and cohesiveness) were analysed using a texture analyzer. The Power law, Casson and Windhab rheological models were used in order to better explain the rheological behaviour of Chocolate samples. Results showed that white Chocolate, with the highest amount of fat in formulation, had the smallest sized particles, the less aggregate structure and the lowest yield stress, viscosity and thixotropic values. Dark Chocolate samples instead presented the highest aggregate structure, with less void spaces between particles that involved the highest rheological parameter values. Milk Chocolate matrix exhibited intermediate microstructural and rheological characteristics compared to dark and white Chocolate ones.

  • Microstructural and Rheological Properties of White Chocolate During Processing
    Food and Bioprocess Technology, 2015
    Co-Authors: Virginia Glicerina, Francis Balestra, Marco Dalla Rosa, Simona Romani
    Abstract:

    The relationship between the microstructural and rheological properties of white Chocolate was studied during the main steps (mixing, pre-refining, refining, conching and tempering) of the manufacturing process. Laser light diffraction and light microscope techniques were used to study the particle size distribution (PSD) and the modifications of the network structure of the samples. Rheological parameters in terms of yield stress, apparent viscosity and thixotropy were evaluated by using a stress-strain controlled rheometer. The Casson and Windhab rheological models, which are widely used for dark and Milk Chocolate matrices, were used in order to explain better the rheological values obtained from the flow curves . Particle analysis revealed significant changes in the network structure during process. In particular, from the mixed sample to the refined one, a reduction in particle size was found; Sauter ( D[3.2]) and Feret diameters decreased, the former from 18.6 to 6.67 μm and the latter from 320 to 33 μm. Consequently, an increase in the matrix aggregation was observed. The white Chocolate samples obtained from the conching and tempering steps were characterized by the statistically lowest values of yield stress and apparent viscosity and by the weak structure. Moreover, the samples were well discriminated by both rheological models applied. [ABSTRACT FROM AUTHOR]

  • Effect of manufacturing process on the microstructural and rheological properties of Milk Chocolate
    2015
    Co-Authors: Virginia Glicerina, Francis Balestra, Dalla M. Rosa, Simona Romani
    Abstract:

    The effect of different process steps on microstructural, rheological and visual properties of Milk Chocolate was studied. Each process step affects the microstructural characteristics of Milk Chocolate, involving modifications on its macroscopic properties, such as rheological attributes. Milk Chocolate samples were obtained at each phase of the manufacture process: mixing, pre-refining, refining, conching and tempering. Microstructural properties (network structure and particle size) and rheological parameters (yield stress, apparent viscosity, thixotropy, G′ and G″) were evaluated by using respectively an environmental scanning electron microscope (ESEM), and a controlled strain-stress rheometer. Colorimetric analyses (L∗, h° and C∗) were also performed. ESEM analysis revealed important changes in the network structure during process, with a reduction in particle size and an increase in the voids between aggregates, from the mixing to the refining step. Moreover, an increase of all rheological analyzed parameters from mixed sample to the refined one was found. Samples obtained from the conching and tempering steps were characterized by the lowest statistically significantly values of all rheological parameters. This could be related to the changes in the structure aggregation evidenced by ESEM analysis. From colour results, the samples with the finest particles appeared lighter and more saturated than those with coarse particles

Homayouni Rad A. - One of the best experts on this subject based on the ideXlab platform.

  • Effects of polyols on the quality characteristics of sucrose-free Milk Chocolate produced in a ball mill
    RSC Advances, 2019
    Co-Authors: Homayouni Rad A., Rasouli Pirouzian H., Toker O.s., Genc Polat D.
    Abstract:

    Sucrose-free Milk Chocolates containing different types of bulk (isomalt, xylitol and maltitol) and high intensity (Stevia) sweeteners were produced by using a ball mill. The main quality characteristics of the formulated Chocolates were evaluated and compared with those of the conventional sample containing sucrose. The Casson model was the best fitting model for the rheological data. Casson viscosity and Casson yield stress were significantly affected by the type of bulking agent in Chocolates formulated with xylitol (p < 0.05). However xylitol notably improved the overall acceptability according to the sensory analysis results. Chocolates containing the sucrose replacers demonstrated lower Tonset values and higher enthalpy than the control sample. Sucrose-free Chocolates illustrated a higher degree of particle agglomeration. Bulk sweeteners meanwhile seem to have high potential for Milk Chocolate production with low calorie values by using the ball mill technique. Industrial applications: the production of sucrose-free Chocolates with conventional methods requires a lot of time and energy. Recently, using alternative methods for Chocolate production has been raising interest in many small industries. This study proposed a ball mill method for the preparation of sucrose-free Milk Chocolates with physiochemical properties almost ranging in the standard limit defined for Chocolate. Although using the ball mill method presents a more cost-effective technique for Chocolate production and provides shorter processing times for small Chocolate industries, it seems to be less efficient in evaporating moisture than the conventional processing. Challenges are still ahead for upgrading this alternative technique to be efficient in evaporating more moisture during operation ending in a high quality product