Milk Chocolate Samples Research Articles

Improving particle size distribution and flow properties of milk chocolate produced by ball mill and blending

Chocolate mass is produced by roller refining and conching or alternatively by ball milling. Grinding can generate varying particle size distributions (PSD), which again influence flow parameters. The latter are very important for downstream processing as well as mouthfeel and consumer acceptance of the final product. The objective of the work was to influence and control PSD and flow properties of ball mill chocolate. Various milk chocolate samples were produced in laboratory and pilot scale, and their PSD and flow properties were measured. First, it was tried to pre-grind milk and cocoa particles to very small size and then to produce coarser sugar particles in order to achieve a bimodal PSD. This should increase package density, which makes more fat available for the flow process. The attempt did not work very well for various practical reasons. Secondly, when instead fine and coarse fractions of the same particle composition were blended, it was possible to achieve bimodal PSDs as they are known from roller-refined products. The lowest values for flow parameters were achieved with a mix of 63 % coarse and 37 % fine particles as predicted in the literature. Thirdly, it was tested to blend roller-refined and ball-milled samples. It was possible to use one-third of the latter without considerably changing flow properties. This opens up various practical possibilities for the industry, e.g. line extension and productivity increase with relatively little effort and investment.

Using polydextrose as a prebiotic substance in milk chocolate: effects of process parameters on physical and rheological properties

Polydextrose, a functional food ingredient, is potentially a prebiotic substance. The rise in diet-related illness has led consumers to take a greater interest in the ingredients of food products. In the present study, in an effort to obtain a prebiotic milk chocolate, the effects of various levels of polydextrose (0, 60, 90 and 120 g/kg) and the use of varying conching times (CT) (3.50, 4.0 and 4.50 h) and refining conditions (20.0, 25.0 and 28.0 µm mean particle size, D[4,3]) in the sample preparation process were examined and analysed with respect to the physical and rheological properties of milk chocolate samples. The use and amount of polydextrose and CT and particle size had statistically significant effects with different magnitudes and directions on the physical and rheological properties of the samples. The samples containing polydextrose significantly differed from the control samples, especially with respect to their rheological properties (p < 0,01).

Impact of fat content during grinding on particle size distribution and flow properties of milk chocolate

Consumer acceptance depends on taste and mouth feeling. Processing can generate varying particle size distributions (PSD), which again influence flow parameters. Chocolate can be produced by roller refining and conching or alternatively by ball milling. Fat content during milling is an important parameter of both processes. The aim of this project was to elucidate relationship between this processing parameter, PSD and flow properties, so they can be controlled. Milk chocolate samples were produced in pilot scale and measured. The results showed that varying fat contents influences PSD for both processing types. Higher fat contents resulted in bimodal distributions for roller refining. Small particles fill voids between big ones, improve packing density and liberate fat for flowing. Nevertheless, fat content during refining should not be too high either, as downstream conching requires low initial content. Pre-dried raw materials were used for ball milling, since this process offers few possibilities to evaporate water and undesired volatiles, unlike conventional conching. Samples showed narrower, multi-modal PSDs. The lack of fine particles decreases packing density and results in higher viscosity at medium and high shear rates. Viscosity at low shear can be less than for roller refined products, which is a consequence of reduced specific surface. Unlike roller refiners, the PSDs became broader at lower fat contents. Almost bimodal PSDs were achieved in lab scale at very low fat contents. Under industrial conditions, the mass must be pumpable for milling. This is a restriction for influencing properties via PSD and needs further optimization.

Ethylcellulose solvent substitution method of preparing heat resistant chocolate

In the present study a structuring technique was developed to produce chocolate which resists deformation at temperatures above 40°C. It was hypothesized that by adding ethylcellulose (EC) solubilized in ethanol (EtOH) to chocolate and evaporating the EtOH an organogel could be formed in situ with the fat phase of the chocolate. Heat resistant chocolate (HRC) was produced by mixing a 20% EC in EtOH solution with molten chocolate. The EtOH was evaporated and the resulting chocolate was incubated at 40°C for 2h and tested for hardness. The effect of various EC viscosities (4, 10, 20, 22, and 45cP) and concentrations ranging from 1.0 to 2.2% on different types of chocolates was studied. Milk chocolate containing 1.9% EC had a hardness of 26.0N whereas the control chocolate was too soft to be tested. Further experiments revealed that white and dark chocolates had hardnesses of 29.5 and 10.5N, respectively. The hardness of the chocolate was dependent on the chocolate formulation and concentration of EC, and independent of EC viscosity. It was observed that the addition and evaporation of EtOH from the compound milk chocolate samples led to an increase in the lightness of the chocolate surface if the EtOH was evaporated at temperatures of 40°C or higher. Addition of EC to chocolate represents a new strategy for the manufacture of HRC. Future work should focus on determining the mechanism by which heat resistance is achieved in these chocolates.

Oral processing of two milk chocolate samples

Oral processing of two milk chocolates, identical in composition and viscosity, was investigated to understand the textural behaviour. Previous studies had shown differences in mouthcoating and related attributes such as time of clearance from the oral cavity to be most discriminating between the samples. Properties of panellists' saliva, with regard to protein concentration and profile before and after eating the two chocolates, were included in the analysis but did not reveal any correlation with texture perception. The microstructure of the chocolate samples following oral processing, which resembled an emulsion as the chocolate phase inverts in-mouth, was clearly different and the sample that was found to be more mouthcoating appeared less flocculated after 20 chews. The differences in flocculation behaviour were mirrored in the volume based particle size distributions acquired with a laser diffraction particle size analyser. The less mouthcoating and more flocculated sample showed a clear bimodal size distribution with peaks at around 40 and 500 μm, for 10 and 20 chews, compared to a smaller and then diminishing second peak for the other sample following 10 and 20 chews, respectively. The corresponding mean particle diameters after 20 chews were 184 ± 23 and 141 ± 10 μm for the less and more mouthcoating samples, respectively. Also, more of the mouthcoating sample had melted after both 10 and 20 chews (80 ± 8% compared to 72 ± 10% for 20 chews). Finally, the friction behaviour between a soft and hard surface (elastopolymer/steel) and at in-mouth temperature was investigated using a commercial tribology attachment on a rotational rheometer. Complex material behaviour was revealed. Observations included an unusual increase in friction coefficient at very low sliding speeds, initially overlapping for both samples, to a threefold higher value for the more mouthcoating sample. This was followed by a commonly observed decrease in friction coefficient with increasing sliding speed (mixed and elasto-hydrodynamic regime), steeper in the case of the more mouthcoating sample until the differences between the two samples became negligible at a sliding speed of ≈0.2 mm s(-1). The stark differences in the tribological behaviour in these regimes begin to allow correlation of data from sensory and physical measurements based on insight into the underlying material behaviour. The complex picture also included comparable behaviour of both samples in the late stages of the elasto-hydrodynamic regime and the early stages of the hydrodynamic regime, until a change of slope was observed and then, at higher sliding speeds, the less mouthcoating sample showed higher friction coefficients. In conclusion, this research uncovered novel correlations of a complex food composite between the sensory behaviour and the physical material properties relating to melting and friction behaviour.

‘Bouba’ and ‘Kiki’ in Namibia? A remote culture make similar shape–sound matches, but different shape–taste matches to westerners

Western participants consistently match certain shapes with particular speech sounds, tastes, and flavours. Here we demonstrate that the ‘Bouba–Kiki effect’, a well-known shape–sound symbolism effect commonly observed in Western participants, is also observable in the Himba of Northern Namibia, a remote population with little exposure to Western cultural and environmental influences, and who do not use a written language. However, in contrast to Westerners, the Himba did not map carbonation (in a sample of sparkling water) onto an angular (as opposed to a rounded) shape. Furthermore, they also tended to match less bitter (i.e., milk) chocolate samples to angular rather than rounded shapes; the opposite mapping to that shown by Westerners. Together, these results show that cultural–environmental as well as phylogenetic factors play a central role in shaping our repertoire of crossmodal correspondences.

Influence of conching temperature and some bulk sweeteners on physical and rheological properties of prebiotic milk chocolate containing inulin

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.

“Bouba” and “Kiki” in Namibia? A remote culture make similar shape–sound matches, but different shape–taste matches to Westerners

Western participants consistently match certain shapes with particular speech sounds, tastes, and flavours. Here we demonstrate that the “Bouba-Kiki effect”, a well-known shape–sound symbolism effect commonly observed in Western participants, is also observable in the Himba of Northern Namibia, a remote population with little exposure to Western cultural and environmental influences, and who do not use a written language. However, in contrast to Westerners, the Himba did not map carbonation (in a sample of sparkling water) onto an angular (as opposed to a rounded) shape. Furthermore, they also tended to match less bitter (i.e., milk) chocolate samples to angular rather than rounded shapes; the opposite mapping to that shown by Westerners. Together, these results show that cultural–environmental as well as phylogenetic factors play a central role in shaping our repertoire of crossmodal correspondences.

Chocolate and Cocoa Products as A Source of Essential Elements in Nutrition

In order to test current quality and nutritional merits of chocolate, 54 dark, plain and milk chocolate samples as well as cocoa were collected from the Austrian market and analyzed for many nutrient, essential and non essential elements, including the non-metals B, Si, S, and I. The cocoa contents ranged from 20-100%. Among the nonwanted trace elements, nickel was Gaussian distributed with a rather high mean of 4.9 mg/kg. Cd largely ranged below 0.20 mg/kg, but a few were higher, reaching 0.90 mg/kg. Contrary to previous studies, the same sample set was used to determine the contents of several element groups to look for interelement effects. Compared with element levels met in other sweets, element contents in chocolate were significantly higher. Many trace elements, like B-Co-Cr-Cu-Fe-Mn-Zn, ranged at levels met in green plants. Nickel concentrations were surprisingly high and about Gaussian distributed. Silicon was frequently higher than aluminium. Contaminants Pb, As, V, and Tl were very low, Cd was variable. Factor analysis grouped the element concentrations into B-Co-Cu-Mg-Mn-Ni- P-S-Zn, Al-Cr- Fe-Si, and Ca-J-Na, which might represent a component from the cocoa bean, its outer shell, and milk. Contrary to other sweets, consumption of 100 g of chocolate satisfies the recommended daily intake for Cr-Cu-Fe, and 300 g for Mg and Zn, which is particularly important for the adequate trace element supply of children and vegans.

DETERMINATION OF FAT CONTENTS WITH SUPERCRITICAL CO2 EXTRACTION IN TWO COMMERCIAL POWDER CHOCOLATE PRODUCTS: COMPARISON WITH NP‐1719

ABSTRACTFat content is an important variable in chocolate and cocoa powder production. Current Association of Official Analytical Chemists‐approved methods may require up to 18 h for determination of fat content data, like Portuguese Norma, NP ‐1719. Supercritical carbon dioxide (SC‐CO2) extraction of fats from chocolate products eliminates solvent and solvent disposal costs and exposure to hazardous reagents.SC‐CO2 fluid extraction of extracts from samples of commercial powder milk chocolate, 5–6 g, was carried out in a modified commercial flow apparatus, at temperatures from 313.15 to 353.15 K, pressures up to 60.0 MPa and flow rates from 0.16 kg/h to 0.47 kg/h of CO2. Percent fat values were determined gravimetrically by collecting the extract into a preweighed trap.Recoveries using a 20‐ to 25‐min supercritical fluid extraction method were between 98 and 100% of NP‐1719 values with standard deviations on replicates ranging from 0.4 to 0.6%. The main compounds identified in the extracts were palmitic acid (28–30%), stearic acid (30–33%), oleic acid (29–30%) and linoleic acid (2–4%).The possibility of replacement of NP‐1719 method by a SC‐CO2 extraction was demonstrated.PRACTICAL APPLICATIONSCarbon dioxide is the most used supercritical solvent for application in the food and related industries (mainly because it is noninflammable, cheap and nontoxic). With this solvent, it is possible to obtain solvent‐free extracts and to avoid the degradation of thermally labile components; therefore, the natural odor and aroma of the starting material are retained. The operational optimization studies and the important properties of the extracts expected to be present are lines of research. In this case study, with applications to the industry as analytical technique, we can improve the time required to determine the total fat content and characterize the components present in two different commercial powder chocolate products.

Rapid Raman mapping for chocolate analysis

Raman microspectroscopy mapping capabilities have advanced significantly and have been applied to cell and pharmaceutical tablet formulation analysis. Bulk Raman investigations of food and their constituents have been carried out but little work exists on the application of Raman mapping capabilities to food. Here, we assess the applicability of Raman microspectroscopy mapping to the analysis of chocolate and examine both white and milk chocolate samples. It was found that the sucrose, lactose and fat constituents of white chocolate could be extracted and spatially resolved, indicating that the sucrose and lactose formed particles within a matrix of ‘fats’. Fluorescence from cocoa solids present in milk chocolate prevented chemical mapping with the instrumentation used. Raman mapping should provide a powerful analytical technique for the analysis and development of food products.

New Ni(II) Ion-Selective Electrode Based on the N-S Schiff Base Ligand as Neutral Carrier in PVC Matrix

A nickel(II) [Ni(II)] ion-selective electrode was prepared by incorporating a new N-S Schiff base ligand, glyoxal-bis(S-benzyldithiocarbazate) (GBSB), as a neutral carrier into the PVC matrix. The proposed electrode exhibits an excellent near-Nernstian response for Ni2+ ions, ranging from 2.8 × 10−7 to 1.0 × 10−1 mol/L with a detection limit of 1.2 × 10−7 mol/L and a slope of 31.9 ± 0.3 mV/dec in pH 4.0 nitrate buffer solution at 25°C. It has an appropriate response time and suitable reproducibility and can be used for at least 3 months. The operational pH range of the proposed electrode is 4.0–7.5. The response mechanism is discussed in view of the alternating current (AC) impedance technique. In addition, the electrode was successfully used as an indicator electrode in potentiometric titration of Ni2+ ion and in the direct determination of Ni2+ ion in milk power and chocolate samples.

Gas-Liquid Chromatographic Determination of Milk Fat and Cocoa Butter Equivalents in Milk Chocolate: Interlaboratory Study

A collaborative trial was conducted to validate an analytical approach comprising method procedures for determination of milk fat and the detection and quantification of cocoa butter equivalents (CBEs) in milk chocolate. The whole approach is based on (1) comprehensive databases covering the triacylglycerol composition of a wide range of authentic milk fat, cocoa butter, and CBE samples and 947 gravimetrically prepared mixtures thereof; (2) the availability of a certified cocoa butter reference material for calibration; (3) an evaluation algorithm, which allows reliable quantitation of the milk fat content in chocolate; (4) a subsequent correction to take account of the triacylglycerols derived from milk fat; (5) mathematical expressions to detect the presence of CBEs in milk chocolate; and (6) a multivariate statistical formula to quantitate the amount of CBEs in milk chocolate. Twelve laboratories participated in the validation study. CBE admixtures were detected down to a level of 0.5 g CBE/100 g milk chocolate, without false-positive or -negative results. The applied quantitation model performed well at the statutory limit of 5% CBE addition to milk chocolate, with a prediction error of 0.7%, and HorRat values ranging from 0.8 to 1.5. The relative standard deviation for reproducibility (RSDR) values for quantitation of CBEs in analyses of chocolate fat solutions ranged from 2.2 to 3.8% and for analyses of real chocolate samples, from 4.1 to 4.7%, demonstrating that the whole approach, based solely on chocolate fat blends, is applicable to real milk chocolate samples.

Chocolate authenticity control concerning compliance with the conditions for adding cocoa butter equivalents as laid down by Directive 2000/36 EC

Chocolate samples (22 in total, including 11 samples of milk chocolate) were bought from retail store in Prague and tested for their CBEs contents in relation to the declaration of CBE addition on the product labels. The modified method of Padley and Timms was employed for determining selected triglycerides (C50, C52 and C54). The presence of CBEs in chocolate was evaluated using the following relationship: %C50 &amp;lt; 44.095 &amp;ndash; (0.737 &amp;times; %C54). The content of CBE in chocolate was determined using the method of Young, modified by the replacement of the original graphical procedure with the numerical processing of the results. 19 samples i.e. 90% of the total, satisfied the requirements of Directive 2000/36/EC. In view that no official methods for CBE detection and quantification in chocolate have been published up to now and older methods were used in this work, the results published here should be considered as indicative and satisfying the requirements for screening only. &amp;nbsp; &amp;nbsp; &amp;nbsp;

Tolerance of symptomatic lactose malabsorbers to lactose in milk chocolate.

To study tolerance to lactose in milk chocolate among symptomatic lactose maldigesters. Randomized cross-over study. Twenty-seven adult lactose maldigesters with symptomatic lactose intolerance. A 100 g chocolate sample prepared with whole milk (12 g lactose), whole-milk powder (12 g lactose), low-lactose milk powder (2 g lactose) or lactose-free milk powder was eaten after an overnight fast. Gastrointestinal symptoms (flatulence, abdominal bloating, abdominal pain, borgorygmi and nausea) were recorded in a questionnaire during the following 8 h. Bowel movements and stool consistency were also registered during the test day. The numbers of persons reporting different gastrointestinal symptoms or any of the symptoms did not differ significantly after eating the chocolate samples. No statistical differences were found in the estimated strength of the different symptoms or the total strength of all symptoms combined. Differences in the bowel frequency and stool consistency were also non-significant. Lactose malabsorbers with self-reported lactose intolerence did not differ in their response to milk chocolate samples containing different amounts of lactose.

A COMPARISON OF COMMERCIALLY AVAILABLE PEANUT ELISA TEST KITS ON THE ANALYSIS OF SAMPLES OF DARK AND MILK CHOCOLATE

ABSTRACT Reactions to peanut proteins by certain sensitive members of the population can result in dramatic and potentially catastrophic consequences. While peanut is not the only food known to cause allergies, it is the one that is most closely monitored. To address concerns related to peanut in food products, four commercial test kits have been developed to quantitatively analyze for peanut protein in finished products. This manuscript describes a study undertaken to compare these kits on reference samples of dark and milk chocolate containing known amounts of peanut. The results are mixed with the data suggesting that all kits were suitable for qualitative screening but were not suitable for general quantitative assays.

COMPARISON OF MONADIC AND SIMULTANEOUS SAMPLE PRESENTATION MODES IN A DESCRIPTIVE ANALYSIS OF MILK CHOCOLATE

Monadic (one sample served at a time, and all attributes rated for that sample) and simultaneous multiple (4 samples served together, and attributes rated one at a time across samples) presentation and evaluation procedures were compared in terms of descriptive profile generated, panel performance (ability to discriminate, reproducibility, concept alignment) and session duration, in a descriptive analysis of 9 milk chocolate samples by a panel of 18 trained judges. The sensory profiles obtained with the two presentation modes were very similar (as assessed by spider web and principal component plots). Time‐wise, the simultaneous presentation procedure took significantly longer to complete (p&lt;0.001). Judges discriminated slightly better and were more reproducible with the simultaneous presentation mode, but quality of concept alignment did not differ between the two procedures. We conclude each method has its advantages and limitations, and choice of presentation procedure should be based on the type of descriptive analysis carried out and the time frame available.

MULTIVARIATE ANALYSIS OF CONVENTIONAL PROFILING DATA: A COMPARISON OF A BRITISH AND A NORWEGIAN TRAINED PANEL

ABSTRACT.Many studies have shown that conventional profiling provides reproducible and meaningful results. However, comparison of the technique as used in different countries appears to be nonexistent. In addition, data analysis is often approached differently, and this aspect is also addressed. This paper describes a study to compare the results obtained from profiling milk chocolate samples, using trained panels in Britain and Norway. Data were analyzed using principal component analysis, generalized Procrustes analysis and partial least squares regression. Results indicate that the underlying perceptual structure of the sample spaces obtained from both panels were similar, however, the emphasis on the underlying sensory dimensions differed. Moreover, it was possible to calibrate the two profiles, which has implications for marketing products for export, as well as providing a potential tool for panel monitoring and calibration across cultures.

Collaborative Study of the International Office of Cocoa, Chocolate, and Sugar Confectionery on the Use of Motility Enrichment for Salmonella Detection in Cocoa and Chocolate

A comparative collaborative study was performed in 15 laboratories to validate the use of motility enrichment on Modified Semisolid Rappaport-Vassiliadis (MSRV) medium for Salmonella detection in cocoa and chocolate products. The use of MSRV was compared with a cultural procedure using Rappaport-Vassiliadis broth and selenite cystine broth as selective enrichments. Artificially contaminated milk chocolate samples as well as Salmonella reference capsules added to Salmonella-free cocoa and milk chocolate were used as test samples. Motility enrichment produced 347 positive test results compared to 320 for the cultural procedure. For samples containing a lactose positive Salmonella strain, motility enrichment was far more productive than the cultural procedure, while for the other samples no significant statistical difference in the productivity of both procedures was observed at the 5% level.

Rapid High Pressure Liquid Chromatographic Determination of Carbohydrates in Milk Chocolate Products

Abstract A high pressure liquid chromatographic method is described for determining 4 carbohydrates in milk chocolate products. The carbohydrates are extracted with water, chromatographed on a small particle packing with acetonitrile-water (80+20) mobile phase, and quantitated by a refractive index detector and digital integrator. The relationship between peak area and concentration was linear. Retention times and peak areas were reproducible. This procedure was successfully applied to several milk chocolate samples and is rapid and more accurate and precise than the official methods.