Casson Viscosity Research Articles

Effects of surface modification of sucrose particles on chocolate morphology and fat bloom during storage

In this study, a new bloom-reducing approach, modifying the surface of crystalline sugar was introduced and confirmed through two methods (circularity and Casson viscosity). Targeting the effects of sucrose shape on bloom, model chocolates were formulated with 2 sucrose surfaces (before and after modification) at 3 sucrose volume fractions (0.15, 0.50, and 0.75) in the nonfat particle phase. Bloom was evaluated by changes in whiteness index (ΔWI) and white area percentage (WA%), accompanied by polymorphic transition evaluations. Surface morphology during storage was also evaluated by scanning electron microscopy (SEM) to quantify surface roughness and porosity. Bloom and SEM results both showed similar trends: smoothing sucrose particle surface as well as reducing sucrose fraction volume significantly reduced bloom and surface morphological (roughness and porosity) change, indicating that sucrose surface modification may have a significant impact on the particulate microstructures in chocolate thus impeding bloom formation during storage.

Effects of individual phospholipids on chocolate model systems: Particulate interaction, crystallization behavior, and fat bloom during storage

To investigate the effects of phospholipids (PLs) in chocolate, model systems were designed by adding 0.3%, 0.5%, and 0.8% (w/w) phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylserine (PS) to the control system (0.0% PL). Bloom behaviors were quantified by changes in whiteness index (ΔWI), white area percentage (WA%) and surface morphology over 28-day accelerated storage. Bloom was significantly retarded in all PL systems (p < 0.0001), especially showing almost no visual bloom in PE and PS systems during 28-day storage: ΔWI was reduced to below 1.5 (16.97 for the control) and WA% was reduced to below 10% (99.47% for the control). This reduction in bloom was further confirmed by low surface roughness and porosity. Particle interactions (quantified by Casson viscosity and sedimentation volume) were significantly reduced (p < 0.0001) and amount of crystallization (quantified by differential scanning calorimetry and oscillatory rheology) were significantly increased in all PL systems (p < 0.05). These results suggest that PLs can improve the microstructural stability of the nonfat particle phase and the crystalline fat phase, thereby reducing fat migration and preventing bloom formation.

Optimization of Hazelnut Spread Based on Total or Partial Substitution of Palm Oil.

Palm oil is widely used in the manufacturing of hazelnut-based spreads due to its unique fatty acid and triacylglycerol profile and, thus, its crystallization behaviour, which makes it suitable for use in fat-based spreadable products. An interesting solution that enables the replacement of palm oil is given by oleogels made with high nutritional quality oil. In this study, the influence of the replacement of palm oil with different glycerol monostearate/olive oil-based oleogels, as well as the influence of the different amounts of GMS employed in oleogel preparation, on the oil binding capacity, spreadability, and rheological and sensory parameters of hazelnut cocoa spreads was investigated. A design of experiment (DoE) approach, with the adoption of the D-optimal design, was used to plan the cocoa hazelnut spread formulations, with the aim being to identify the optimal formulation with desirable quality parameters in terms of Casson's viscosity, spreadability, and oil binding capacity. The resulting optimized formulation was identified in a spread characterized by a total replacement of palm oil with an oleogel made of 95% olive oil and 5% GMS.

Fortification of chocolate with microencapsulated fish oil: Effect of protein wall material on physicochemical properties of microcapsules and chocolate matrix

Protein stabilized fish oil microcapsules were incorporated into chocolates in order to design fortified product which could bear the nutritional claim “source of or high omega-3 fatty acids”. Protein wall material (soy, whey and potato) influenced microcapsules and chocolate performance. Soy protein resulted in the smallest microcapsules with the lowest content of surface oil. Peroxide values were low even after 14 days of microcapsules storage. Incorporation of microcapsules into chocolate led to increase in Casson viscosity and breaking force as well as decrease in melting enthalpy, due to prevalence of particle–particle over fat-fat interactions. Increase in microcapsules concentration resulted in chocolate with poorer snap and higher tendency to fat bloom formation. Whey protein microcapsules, having the largest diameter, resulted in chocolate with the lowest breaking force and melting enthalpy and the highest whitening index. In general, microcapsules addition did not require chocolate production modification and led to sensory acceptable product.

Reduced-fat chocolate spreads developed by water-in-oleogel emulsions

This paper reports the successful development of low-fat chocolate spreads using water-in-oleogel emulsions. Glycerol monostearate (20% wt) was incorporated into corn oil to fabricate the oleogel phase and then water was mixed with oleogel at weight ratios of 0:100, 45:55, 50:50, and 55:45 (water: oleogel) to produce water-in-oleogel emulsions. The chocolate spreads prepared with water-in-oleogel emulsions were analyzed and compared in terms of physical, rheological, and sensory characteristics. It was found that the emulsion made at 45:55 water: oleogel ratio (45% replacement of oleogel with water), resulted in chocolate with quite similar microstructural integrity, water activity, Casson viscosity, yield stress, linear viscoelastic region, firmness, and spreadability to the reference sample (100% of oleogel). Moreover, the reduced-fat chocolate spread displayed comparable (if not superior) sensory scores and acceptability to the full-fat sample. In conclusion, water-in-oleogel emulsion displayed the potential for use in the formulation of reduced-fat chocolate spread. • Water-in-oleogel emulsions were produced at various weight ratios (0–55% water). • Oleogel-based emulsions were used in preparation of reduced-fat chocolate spreads. • A sample with 45% lower fat had properties close to the full-fat chocolate. • Fat reduction led to higher aroma, flavor, and acceptability scores in chocolates.

Physiological and Metabolic Adaptation to Heat Stress at Different Altitudes in Yaks.

Yaks have strong adaptability to extremely cold and hypoxic conditions but are susceptible to high ambient temperature when yaks are raised in low-altitude areas during the high-temperature season. Twenty-four adult male yaks with similar weights and ages were randomly divided into TN (Thermoneutral, altitude = 3464 m), LHS (Light heat stress, altitude = 1960 m), and MHS (Medium heat stress, altitude = 906 m) groups to evaluate adaptation strategies to HS. Non-targeted and targeted metabolomics were applied to investigate the effects of different extents of HS on yaks. LHS- and MHS-yaks showed higher rectal temperatures and respiratory rates than TN-yaks. MHS-yaks had higher levels of red blood cells (RBCs), hemoglobin (Hb), whole blood relative index of middle shear at a shear rate of 5 S-1 (WMS), whole blood relative index of high shear at a shear rate of 200 S-1 (WHS), Casson viscosity (CV), middle shear flow resistance at a shear rate of 5 S-1 (MSFR), and high shear flow resistance at a shear rate of 200 S-1 (HSFR) as compared to TN- and LHS-yaks. Differential metabolites and metabolic pathways, including fatty acid metabolism, lipid metabolism, glucose metabolism, and amino acid metabolism, were altered by HS. Metabolites in the glucose metabolism pathway in LHS- and MHS-yaks were lower than those in TN-yaks. However, LHS-yaks showed higher levels of metabolites in the HIF-1 signaling pathway compared to TN- and MHS-yaks. Most of the tricarboxylic acid cycle (TCA) intermediates and fatty acids were significantly decreased in MHS-yaks compared to the other two groups. As a whole, yaks raised at a low altitude (25.6 °C) suffered from severe HS, but they adapted to HS with vasodilatation for dissipating heat and the increased antioxidants and metabolite levels of energy substrates.

Cocoa Spread with Grape Seed Oil and Encapsulated Grape Seed Extract: Impact on Physical Properties, Sensory Characteristics and Polyphenol Content.

The aim of this study was to utilize grape pomace, as a polyphenol-rich by-product of wine production, in the manufacture of enriched cocoa spread. The formulation of the cocoa spread has been modified by substitution of refined sunflower oil with cold-pressed grape seed oil. The spread with grape seed oil (Cg) was further enriched with grape seed extract encapsulated on maltodextrins (E), where 10% and 15% of E was added to Cg obtaining the samples Cg10 and Cg15. The results showed an increase in volume-weighted mean in spread samples, from 19.17 μm in Cg to 19.71 μm in Cg10 and 21.04 μm in Cg15. Casson yield stress and Casson viscosity significantly (p ˂ 0.05) increased from 16.41 Pa and 1.58 Pa·s in Cg to 29.45 Pa and 5.70 Pa·s in Cg15 due to the reduction of the fat-phase content in enriched spreads. The addition of E had no significant effect on the melting temperature (Tpeak) of the enriched spreads, while increasing the amount of E significantly (p ˂ 0.05) increased their hardness. The incorporation of grape seed oil in the cocoa spread formulation contributed to an increase in total polyphenols and flavonoids. Moreover, the addition of 10% and 15% of E to Cg resulted in approximately 1.5× and 2× higher content of phenolic compounds in Cg10 and Cg15 compared to control spread with sunflower oil (Cs). Flavonoids increased from 0.43 mg CE/g in Cs to 0.74 mg CE/g in Cg 10 and 1.24 mg CE/g in Cg15. Encapsulates positively affected sensory characteristics of enriched spread samples by reducing their grape seed oil aroma and sweetness.

Rheological and tribological characterization of different commercial hazelnut-based spreads.

Five commercial hazelnut/cocoa spreads with different compositions were tested by rheology/tribology. The impact of each formulation on the structural/lubricant performances was investigated. Rotational/oscillatory rheology was chosen to assess material behavior during flow. Viscosity variation as a function of temperature and chamber geometry was evaluated. Oscillatory mode tests were carried out to obtain information on product viscoelasticity. Tribological analysis was performed at different temperatures aiming at simulating the chewing/swallowing process. All samples were categorized as pseudo-plastic and viscoelastic materials, with the elastic component prevailing over the viscous one. Major differences were detected in terms of consistency index, depending on the total lipid content. Temperature increase enhanced spread fluidity with a decreasing viscosity according to the Arrhenius model (R2 > 0.942) and greater values of activation energy reflecting higher sensitivity to microstructural changes. An inverse relationship between Casson viscosity and sugar/fat ratio highlighted additional correlations between structural parameters and spread formulation. Tribological measurements at 25°C highlighted that, at the initial eating stage, the friction factor (0.112-0.262 at sliding velocity of 8× 10-6 m/s) was strongly affected by either the amounts of solid fat or hazelnut percentage. Tribological data corroborated the theory for which tribology and rheology cover different domains.

Variational multiscale stabilized finite element analysis of non-Newtonian Casson fluid flow model fully coupled with Transport equation with variable diffusion coefficients

This paper presents a new subgrid multiscale stabilized formulation for non-Newtonian Casson fluid flow model tightly coupled with variable diffusion coefficients Advection–Diffusion–Reaction equation (VADR). Both the subscales are chosen to be time dependent and the stabilized formulation has been reached through the complete elimination of the unresolvable scales in terms of the coarse scale solution. Hence the resultant formulation emerges as a set of equations involving only the coarse scale solution instead of multiple scales and makes the formulation simpler to handle. In this study the shear-rate dependent Casson viscosity coefficient is assumed to be a function of the solute mass concentration, resulting in a two way coupling. This paper investigates the stability and the convergence properties of the stabilized finite element solution, without imposing any additional regularity condition other than the admissible space requirement on it. The proposed expressions of the stabilization parameters play a significant role in obtaining optimal order of convergences. During various theoretical derivations the estimations of the non-linear apparent viscosity coefficient have been carefully carried out assuming sufficiently regular exact solution. The performance of the scheme has been numerically validated with lid driven cavity problem. The theoretically established rate of convergence results are appropriately verified through numerical studies. In addition the transient Casson fluid flow behavior in a flow past square cylinder has been analyzed thoroughly.

Effect of inulin, fructo-oligosaccharide, trehalose or maltodextrin (M10 and M30) on the physicochemical and sensory properties of dark compound chocolate

The sucrose-free dark chocolate development is receiving attention due to increasing market demand for foods with reduced sugar. This study aimed to determine the physical and sensory properties, and the storage stability of sucrose-free dark compound chocolate by replacing the sucrose with inulin, Fructo-oligosaccharides (FOS), trehalose, or maltodextrin (M10 and M30) on a volume basis along with stevioside as a sweetening agent. Melting and crystallization properties, particle size, moisture content, rheological behaviour, hardness, bloom formation and sensory evaluation were examined using differential scanning calorimetry, particle size analyser, rheometer, and texture analysis, respectively. Sucrose substitution had no significant impact on the melting and crystallization behaviour in a compound chocolate model system. However, all sucrose-free dark compound chocolate displayed lower Casson viscosity, yield value and hardness than sucrose-containing dark compound chocolate, which may because the weaker particle-particle interaction in sucrose-free dark compound chocolate. Sucrose-free dark compound chocolate had lower sweetness (P < 0.05) and stronger bitterness (P < 0.05) compared to the sucrose compound chocolate. Trehalose was the most suitable sucrose replacer in dark compound chocolate because it resulted in similar rheological and sensory properties as the sucrose-containing dark compound chocolate and greater resistance to bloom formation after 12 weeks of storage.

Effects of composition, temperature and shear rate on chocolate milk rheology: an empirical modeling approach incorporating yield behavior

Abstract This study elucidates the effects of composition and temperature on the rheological behavior of chocolate milk formulation. The fat [0.5, 1 and 1.5 g] and xanthan gum contents [0.05, 0.1 and 0.15 g] varied and shear stress-strain rate data were recorded at varying temperature [21.4, 65 and 80 °C]. All compositions showed predominantly a pseudoplastic behavior [i.e., pseudoplasticity index, n &lt; 1] with a strong influence on composition and temperature. Three semi-empirical rheological models, i.e. Power-law, Herschel–Bulkely, and Casson models were fitted on the data using an in-house developed computer program for the best statistical fit. The pseudoplasticity index [n] varied with the composition that initially decreased with temperature and subsequently increased. The other model parameters such as consistency index [k], Casson and Herschel–Bulkely yield stress, and Casson viscosity [at a specified rate i.e., 34.7 s−1] were computed through model fitting and correlated to the microstructural changes inside the fluid keeping in view the composition and temperature. This study helps in correlating chocolate milk processing and quality control based on complex microstructure to the rheological parameters measured at simulated temperatures and shear rates.

Carob powder as cocoa substitute in milk and dark compound chocolate formulation.

In the current research, the possibility of using carob powder as a substitute for cocoa powder in milk and dark compound chocolates was investigated. Five chocolate samples containing carob powder (20, 40, 60, 80 and 100%) along with control were produced and the physico-chemical analyzes were measured. Chocolate samples were assessed for sensory acceptance by a hedonic scale. The outcomes indicated that chocolate formulations with lower content of carob powder presented higher quality in terms of color parameters, mean particle size and hardness (values close to control). The addition of carob powder resulted in decreased yield stress in dark chocolates. Also dark chocolate formulations containing high levels of carob powder recorded Casson viscosity values similar to control. Moreover, the milk chocolates containing 40% carob powder illustrated no significant differences in sensory properties with control. However acceptance of the dark chocolate samples was similar to control in all attributes. The results proved that it is possible to utilize carob powder to replace cocoa powder in chocolate production in order to improve nutritional values (higher fiber and fewer calories) with agreeable sensory attributes.

Enrichment of dark chocolate with vitamin D3 (free or liposome) and assessment quality parameters.

Liposomes are suitable carrier for bioactive components. Ethanol injection method was chosen for preparation liposomes included vitamin D3 for addition into dark chocolate [5µg/serving (10g)]. Assessment the quality of prepared liposomes were performed by measurement particle size distribution, zeta potential, loading efficiency and FTIR. Loading efficiency was 62.58 ± 1.2%. It could be concluded the chosen method for liposome preparation was suitable. In vitro release of vitamin D3 from liposome structure showed the release follow Korsmeyer-Peppas model. Fortified chocolate properties included Differential Scanning Calorimeter (DSC), color indexes, casson viscosity and sensory properties were evaluated. According to the results, there was no significant changes in all tested properties in fortified chocolate than control sample. Vitamin D3 retention during storage time (0, 15, 30, 45, 60 and 70days) were evaluated and results revealed there was better retention of vitamin D3 in fortified samples with liposomes than free vitamin D3. Observation showed addition both forms of vitamin D3 (free or liposome) had no significant impact on color indexes, rheological properties, DSC parameters as well as sensory characteristics.

Properties of dark chocolate enriched with free and encapsulated chlorogenic acids extracted from green coffee

Abstract To increase the functionality of dark chocolate, chlorogenic acids extracted from green coffee were added in free or encapsulated forms at different concentration (10, 20, 30, 40 and 50 mg/5 kg of free chlorogenic acids and equal quantity of encapsulated form). The extraction of chlorogenic acids was carried out by maceration of ground green coffee beans in distilled water (30 min at 80 °C), then, cooling, filtration and adsorption by active carbon were done. The final step was filtration and desorption from active carbon and rotary drying (at 60 °C and 120 rpm). Encapsulation of chlorogenic acids was done by coacervation of pectin and gelatin. For quality assessment, several analysis on chocolate samples were performed included color index and melting behavior by Differential Scanning Calorimeter. Flow behavior of the chocolate samples melted at 40 °C was determined using stress or strain controlled rheometer. The microstructure of the chocolate samples was analyzed by Scanning Electron Microscope technique at 500-1000x magnification. Particle size distribution and sensory evaluation was also performed. Results showed addition of free and encapsulated forms of chlorogenic acids decreased Tonset, Tpeak and ΔH of dark chocolate. Casson viscosity increased in the case of addition chlorogenic acids. Color indexes of chocolate samples were influenced by addition of chlorogenic acids. Particle size distribution decreased with addition of free form and increased when encapsulated form was added. Sensory characteristics were also influenced by chocolate formulation and samples included encapsulated chlorogenic acids exhibit better sensory properties than samples enriched with free form.

Determining casson yield value, casson viscosity and thixotropy of molten Chocolate using viscometer

Flow properties of chocolate highly determine mouthfeel and consumer acceptance. Aside from these, they are also important factors in determining the incorporation of chocolate in food products. This work investigated the possibility of using viscometer to determine the flow properties of molten chocolate. The data obtained from viscometer was fitted to Casson Model. Afterwards, Casson yield value and Casson viscosity were then derived. To observe the homogeneity of molten chocolate, thixotropy value was also determined. In this study, molten chocolate was produced using a stone melanger as an alternative processing method. Four grinding durations, namely 4, 8, 12, and 16 hours, were used to produce 4 types of dark chocolate. The results showed that viscometer was able to determine the value of Casson Model parameters, eventhough the shear rate reached was only approximately 45 s−1. Using this approach, it can be observed that the Casson Yield Value and Casson Viscosity increased as the grinding durations were increased.

Enrichment of white chocolate with blackberry juice encapsulate: Impact on physical properties, sensory characteristics and polyphenol content

White chocolate does not contain fat-free cocoa solids and thus lacks bioactive components. In the present study, white chocolate was enriched with encapsulated blackberry juice in concentrations: 60 g kg−1, 80 g kg−1, and 100 g kg−1. The results showed an increase of volume weighted mean in enriched chocolates with increasing the concentration of encapsulate from 13.06 μm in white chocolate to 18.05 μm in chocolate with 100 g kg−1 of encapsulate. Casson viscosity of chocolate mass increased at the same time (from 0.63 Pa in white chocolate to 1.22 Pa in chocolate with a maximum concentration of encapsulate) due to an increase of specific surfaces of solid particles in chocolate. Internal structure and surface gloss in chocolate with 100 g kg−1 of encapsulate are also affected where the lack of free fat phase caused mat color on the surface. However, the addition of encapsulated blackberry juice to white chocolate led to the creation of new type of enriched chocolate with attractive color and blackberry taste. Total polyphenol content (mg GAE/100 g) of white chocolate is increased from 40.75 to 75.06, 145.86, and 153.95 in chocolates with 60 g kg−1, 80 g kg−1, and 100 g kg−1 of encapsulate, respectively.

Sensory preference and bloom stability of chocolate containing cocoa butter substitute from coconut oil

Coconut oil (CNO) is a main source of cocoa butter substitute (CBS). CBS is proposed to improve the appearance, taste of chocolate and increase the stability of chocolate against bloom formation. Therefore, the objective of the research was to determine the effects of CNO substituted at different levels (0%, 1.5%, 3.0% and 4.5%) on physicochemical, sensory acceptance and bloom stability of the chocolate. The TAG composition differed among the chocolate produced. Substitution of CNO in chocolate formulations reduced the melting profile, Tonset (30.72–28.98 °C), Tpeak (36.64–34.39 °C), and Tendset (40.31–36.36 °C). The rheological behavior, Casson yield and Casson viscosity of the chocolate also decreased. The Casson yield and Casson viscosity decreased as amount of CNO substituted increased. In sensory profiling, the scores for the color of chocolate did not differ significantly with control chocolate. However, the glossiness, taste and overall acceptability of chocolate C was more preferred by consumers with the highest amount of CNO (4.5%) substitution. The chocolate containing CNO shows slower rate of bloom formation during storage compared to control chocolate. Chocolate C had the highest stability against bloom formation. This study suggested that CNO substitution at 4.5% has the potential to improve appearance and taste of the chocolate with less effects on the melting profile and rheological behavior. In addition, application of CNO as CBS able to increase the stability of chocolate against bloom formation.

Rheological, fat bloom, and sensory acceptability effects of mango kernel fat and palm olein blends on chocolate-flavored coatings

The effects of replacing cocoa butter with different percentages and proportions of a mango kernel fat/palm olein (MKF/POL) blend, are reported. Samples were prepared by melting together mango kernel fat, palm olein, cocoa butter and cocoa mass and powdered sugar combinated. The samples were milled, conched, tempered, and molded to obtain three sets of seven samples as follows: one control omitting mango kernel fat and palm olein, and six samples with cocoa butter replacement of 15 and 22.5% and MKF/POL ratios of 2.3, 4.0, and 9.0. Casson viscosity, Casson yield stress, fat bloom and sensory acceptability were all measured. In fact, all samples had achieved a low Casson viscosity (ηCA) and Casson yield stress (τ_oCA), which indicates molding and enrobing as appropriate uses. In addition, some significant differences (p ≤ 0.05) were found among samples. Fat bloom was accelerated in the samples relative to control, but high MKF proportions tended to retard appearance of fat bloom. No differences were observed in organoleptic properties between samples and control.

Influence of autologous blood transfusion in liver transplantation in patients with hepatitis B on the function and hemorheology of red blood cells.

The present study aimed to characterize the function and hemorheology of red blood cells (RBCs) recovered during liver transplantation surgery in patients with hepatitis B and decompensation. A total of 15 hepatitis B patients with decompensation who underwent liver transplantation surgery were included in the present study. Blood samples were recovered during the liver transplantation surgery using an Autologous Blood Recovery System. The morphology and structure of RBCs were characterized and compared between pre-operative and recovered blood samples. In addition, the physiological functions of RBCs were measured and compared between pre-operative and recovered blood samples. No significant differences in the morphological score, 2,3-diphosphoglycerate, Na+K+-ATPase, Ca2+-ATPase, Mg2+-ATPase, malondialdehyde and osmotic fragility were identified between RBCs in the pre-operative and recovered blood samples. The level of free hemoglobin in RBCs of the recovered blood samples was significantly higher than in the pre-operative blood samples (P<0.05). Medium- and high-shear blood viscosities in the recovered blood samples were significantly lower than those observed in the pre-operative blood samples (P<0.05). Casson viscosity in the recovered blood samples was significantly higher compared with the pre-operative blood samples. However, no significant differences (P>0.05) in the low-shear blood viscosity, plasma viscosity, relative blood viscosity, erythrocyte aggregation index or Casson yield stress were identified between recovered and pre-operative blood samples. These findings suggested that autologous blood transfusion in liver transplantation surgery in patients with hepatitis B and decompensation had no significant influence on the morphology, structure, function and hemorheology of RBCs.

Investigating the rheological, microstructural and textural properties of chocolates sweetened with palm sap-based sugar by partial replacement

Palm sugar, a natural alternative sweetener which can be made from the nectar of several species of palm tree flowers, recently gains more interest. Due to its physicochemical characteristics, utilisation of palm sugar as chocolate sweetener results in different quality attributes of chocolate. In this work, a thorough investigation about the influence of palm sugar on the rheological, microstructural and textural characteristics of chocolate was carried out through partial replacement of sucrose as chocolate sweetener. Accordingly, five sucrose–palm sugar blends with different palm sugar (PS) proportion, namely PS0, PS25, PS50, PS75, and PS100 were used as chocolate sweetener. The results showed that the Casson yield value of chocolate containing palm sugar was lower than the Casson yield value of chocolate sweetened with pure sucrose which could be attributed to the presence of agglomerates in the chocolate suspension. However, palm sugar-sweetened chocolate exhibited a higher Casson viscosity and thixotropy which could be mainly attributed to the presence of glucose and fructose and the relatively high moisture content. These factors also influenced the hardness of the chocolate to some extent. A lower melting temperature and enthalpy value of the sugar phase in chocolate were observed by DSC, whereas visualisation using SEM, polarised and normal light microscopy indicated increased agglomeration due to the presence of moisture, amorphous sugar and chemical “impurities”. Rheological behaviour of molten chocolate, hardness and polarised–normalised light microscopy were evaluated at a constant temperature of 40, 20, and 50 °C, respectively, while the melting profile was measured from 20 to 200 °C at a rate of 5 °C/min.