Content uploaded by Miroslav Jůzl
Author content
All content in this area was uploaded by Miroslav Jůzl on Jun 08, 2016
Content may be subject to copyright.
A preview of the PDF is not available
The effect of storage temperature on the quality and formation of blooming defects in chocolate confectionery
Abstract and Figures
The study aimed at assessing changes in the quality of certain types of chocolate products over the storage period with particular focus on the formation and development of fat and sugar bloom in chocolate products. Seven products were selected in collaboration with a chocolate factory to undergo monitoring and analysis and stored at four temperature regimens (6 °C, 12 °C, 20 °C and 30 °C). Five samplings were carried out over the storing period (18 weeks) for evaluation of the dynamics of changes in their quality. Each sampling was accompanied by sensory evaluation; selected physical attributes were also analysed: Changes in colour (ΔE*ab) within the CIE (L*a*b) system and changes in hardness using the TIRAtest 27025. The results showed a significant effect of storing temperature on the intensity of changes in the quality of products. The results of sensory evaluation of selected products showed that the highest quality for the majority of descriptors was achieved by products stored at temperatures of 6 °C and 12 °C. As regards samples stored under the temperature regimen of 20 °C, the products started to show visible differences, caused primarily by the formation of fat bloom while storing at 30 °C proved to be extremely unsuitable for all the tested products. Since storing temperatures of 6, 12 and 20 °C did not considerably affect hardness and colour of each product, no distinct changes occurred under such temperature regimens. From the aspect of analytical measurements of colour and hardness of each product, storing at temperatures of 20 °C can be termed appropriate. In all the analyses, the effect of the temperature regimen of 30 °C was significantly negative due to defects caused by blooms on the chocolate, meaning that such temperatures are not advisable for storing chocolate products, even over a short term.
Figures - uploaded by Miroslav Jůzl
Author content
All figure content in this area was uploaded by Miroslav Jůzl
Content may be subject to copyright.
... Even after ten weeks from the production date, the product's texture stored at 6 °C can be preserved and retains its original attributes. It should keep chocolate products at 12 °C [38]. Ref. ...
... The addition of oil-based additives to chocolate can significantly inhibit the growth of fat blooms. [25] Fat replacemen t Chocolate products containing 6.0 % w/w cocoa butter stearin and 0.15 % w/w sorbitan monostearate can delay fat blooms by 15-45 days [26] Fat replacemen t Chocolate products containing 7.5 % DAG cocoa butter can prevent oil migration caused by a fat bloom [38] Processing treatment Compared to conventional tempering, the Well-tempered β-VI pre-crystallization stage inhibited fat bloom and migration. [29] Processing treatment Using a portable NIR spectrometer in conjunction with a chemometric device, different temperatures can cause changes in the shape of fat polymorphs, resulting in the appearance of fat blooms [43] Processing treatment ...
... significantly reduce the bloom rate in chocolate Processing treatment It is possible to keep chocolate products from blooming by adding maltitol and tagatose sweeteners [31] Processing treatment White chocolate products with stevia and sucralose sweeteners can prevent lower fat blooms if the stevia sweetener content is equal to or greater than the sucralose sweetener content [32] Processing treatment Re-tempering chocolate products can increase fat bloom resistance [34] Processing treatment Without tempering chocolate products, blooming can occur on the 25th day of storage [44] Processing treatment Insufficient tempering time and space for phase separation (particles and fat) resulted in the formation of blooms in chocolate [35] Chocolate storage conditions When chocolate is stored at 20-32 °C, it can bloom [36] Chocolate storage conditions Blooming was observed on the first day of storage at 35 °C. However, after seven days, the sensory quality of chocolate had deteriorated [37] Chocolate storage conditions 12 °C is the optimal temperature for storing chocolate products during their storage period [38] ...
One of the indications of chocolate product degradation is blooming. It is distinguished by the loss of surface shine, which is replaced by a white coating. These effects are caused by insufficient processing, inappropriate chocolate content, and incompatible storage conditions. It can alter these characteristics to enhance chocolate's resistance to blooming and its texture, flavor, and appearance. Several factors must be considered when creating blooming-resistant chocolate, such as chocolate particle size, fat content, processing techniques, and storage conditions. This concise review will discuss fat blooming in chocolate, from its formation to its contributing factors and methods for resolving it.
... As chocolate is a continuous lipid phase, the structural changes in its fat matter may alter volatile release, thus changing the flavor profile of the chocolate [11,14,17,47,48,56,57,66]. As a consequence, chocolates and the related ingredients under study were chemically checked during the 18 months of storage for peroxide and acidity values, polyphenols, and vitamin E [67]. ...
... In the milk chocolate (M sample), brightness and snap increased over time (Figure 2), whereas the intensity of brightness remained constant in D, where the snap became less intense from t0 to t4 (Figure 2a). This was in accordance with Machálková et al. [66], who found a slight deterioration of some mechanical descriptors in the chocolate samples stored at 20 • C. The firmness did not change significantly in D and M samples (Figure 2a,b), while the melting dropped in G and M chocolate (Figure 2c,b). In this regard, Thamke et al. [68] concluded that chocolate with a lower cocoa content was characterized by the greatest melting and creaminess, while the product with the highest cocoa content was characterized as dry dough. ...
... Although D chocolate showed an important loss of polyphenols ( Figure 1B), it maintained the highest content at the end of storage (t4) when the astringency was perceived to be at a medium level, contrary to M and G chocolate (Figure 2b,c). Studies [11][12][13]66,67] have already observed the depletion of polyphenols in cocoa-based products during storage, correlating this loss with their oxidation in the corresponding quinones, which might lead to increases in bitterness, as outlined in D chocolate (Figure 2a). In the same sample, starting from t2, some panelists marked descriptors related to oxidation as "pungent", "closed", "cork", and "dried fig". ...
Background:
While there has been an increasing interest in the health properties of chocolate, limited research has looked into the changes of antioxidants occurring in the time span from production to the best before date, which was a period of 18 months in this study.
Methods:
Humidity, ash, pH, acidity, fiber, carotenoids, retinols, tocopherols, sugars, proteins, theobromine, caffeine, polyphenols, fats, the peroxide value, organic acids, and volatile compounds, along with the sensory profile, were monitored at 18-week intervals for 18 months under conditions simulating a factory warehouse or a point of sale.
Results:
At the end of the storage period, more polyphenols were lost (64% and 87%) than vitamin E (5% and 14%) in cocoa mass and cocoa powder, respectively. Conversely, a greater loss in vitamin E (34% and 86%) than in polyphenols (19% and 47%) was shown in the hazelnut paste and gianduja chocolate, respectively. The sensory profiling of cocoa mass, cocoa powder, and hazelnut paste revealed increases in grittiness and astringency, as well as decreases in melting, bitterness, and toasted aroma. Moreover, in the hazelnut paste and gianduja chocolate, oiliness increased with a toasted and caramel aroma. Furthermore, dark chocolate was more gritty, acidic, and bitter. Milk chocolate lost its nutty aroma but maintained its sweetness and creaminess.
Conclusions:
These results should contribute an important reference for companies and consumers, in order to preserve the antioxidants and understand how antioxidants and sensory properties change from the date of production until the best before date.
... Penetration test was used to determine hardness of the chocolate disks and adhesiveness, defined as the work required to pull the sample away from a surface [30][31][32]. Hardness of chocolate is a good parameter that points out proper control of temperature and stability of the fat crystal network formed during tempering process [33,34]. Treated samples (VeC and SuSDC) showed hardness values lower to the control samples (MiC and DaC), respectively (Table 5). ...
The main physicochemical characteristics of novel artisanal chocolates (both dark and milky) intended for vegan consumers or for those requiring assumption of fewer simple sugars, were analysed. Replacement of milk (with coconut copra, almonds, and soy protein isolates), and sucrose (with coconut sugars, stevia and erythritol, respectively) in dark chocolate, were accounted for by means of texture analysis, rheology, water activity, fatty acid composition, differential scanning calorimetry (DSC) and fast field cycling (FFC) nuclear magnetic resonance (NMR) relaxometry. The vegan sample (i.e., the milk-less one) showed lower values of hardness and adhesiveness as well as a larger peak in the melting behavior at the calorimetric evaluation (DSC). Moreover, the absence of milk resulted in the halving of the yield stress and a decrease in both the apparent and Casson’s viscosity. In the sample of chocolate with less sucrose, the peak temperatures measured at the DSC indicate crystallization of cocoa butter in its best form (Vβ2), unlike in dark chocolate, due to the different sugar composition. Similarly, the Casson yield stress (τ0), increased significantly (almost 70%), with the substitution of sugar. Finally, the results of NMR FFC relaxometry made it possible to identify aggregates of different sizes, laying the basis for its use as a rapid, non-destructive method for chocolate analysis.
... Hardness of chocolate is a good parameter that points out proper control of temperature and stability of the fat crystal network formed during tempering process [24,25]. All treatments (VeC and SuSC) showed hardness values lower compared to the control samples (MiC and DaC) ( Table 4). ...
The confectionery industry is increasingly adopting new solutions and possible formulations to expand the ranges of chocolate products that support food styles linked to either cultural or health choices. The chemical-physical characteristics of chocolates (dark and milk) produced with traditional formulations or intended for vegan or demanding less simple sugars consumers (with a 10% reduction in calorific value), were analysed. The effects of the substitution of milk with coconut copra, almond and isolated soy proteins, and the replacement of sucrose with coconut sugars, stevia and erythritol, have been accounted for by analysing texture, rheology and water activity, differential scanning calorimetry (DSC) and fast field cycling (FFC) nuclear magnetic resonance (NMR) relaxometry. The plant-based sample showed lower values for hardness and adhesiveness in the texture analysis, and a larger peak in the melting behaviour at the DSC. Moreover, the substitution of milk powder caused more than a halving of the yield stress and a similar decrease in apparent and Casson viscosity. The crystallisation of cocoa butter in the substituted-sugar sample involved the β V form, the most desirable crystal form in high-quality chocolate. Results by FFC NMR relaxometry allowed identification of differently sized aggregates whose chemical nature is discussed. FFC NMR relaxometry data confirm those by rheological and DSC investigations.
... Sugar bloom on the one hand is often provoked by humid storage or rapid temperature changes and leads to the loss of surface gloss. Fat bloom on the other side is also known to cause quality related issues visible as a fine whitish layer [82]. Growth of microorganisms is, however, of minor importance in this product group. ...
In both public and private sectors, one can notice a strong interest in the topic of sustainable food and packaging. For a long time, the spotlight for optimization was placed on well-known examples of high environmental impacts, whether regarding indirect resource use (e.g., meat, dairy) or problems in waste management. Staple and hedonistic foods such as cereals and confectionary have gained less attention. However, these products and their packaging solutions are likewise of worldwide ecologic and economic relevance, accounting for high resource input, production amounts, as well as food losses and waste. This review provides a profound elaboration of the status quo in cereal and confectionary packaging, essential for practitioners to improve sustainability in the sector. Here, we present packaging functions and properties along with related product characteristics and decay mechanisms in the subcategories of cereals and cereal products, confectionary and bakery wares alongside ready-to-eat savories and snacks. Moreover, we offer an overview to formerly and recently used packaging concepts as well as established and modern shelf-life extending technologies, expanding upon our knowledge to thoroughly understand the packaging's purpose ; we conclude that a comparison of the environmental burden share between product and packaging is necessary to properly derive the need for action(s), such as packaging redesign. Citation: Bauer, A.-S.; Leppik, K.; Galić, K.; Anestopoulos, I.; Panayiotidis, M.I.; Agriopoulou, S.; Milousi, M.; Uysal-Unalan, I.; Varzakas, T.; Krauter, V. Cereal and
... al. [40], structural changes induced by temperature, or the process of moisture removal, can cause a decrease in the monolayer moisture content. This is as a result of reduction in the number of active polar sites due to chemical and physical changes [41]. Moreover, Labuza et. ...
The study was aimed at establishing storage stability indices of a traditional smoke dried product kamsa, produced from beef. The sample was produced using a standardized method and stored over a period of six months. Data for sorption studies was generated between the temperature ranges of 33.8oC to 50oC for adsorption and desorption using the gravimetric method. The data was analyzed using the Guggeinheim Anderson de Boer (GAB) and the Brunaeur Emmett Teller (BET) model equations. A nonlinear regression analysis method was used to evaluate the constants of the sorption equations. From the results using the GAB model, the monolayer moisture content (Mo) decreased from 0.021 to 0.008gH2O/g solids; the value of the constant K, increased from 0.587 to 1.052; and the value of CG decreased from 2.481 to 2.154. For desorption, the value of Mo decreased from 0.021 to 0.004g H2O/g solids; K increased from 0.587 to 1.035; CG increased from 2.173 to 2.646. The model gave low percent standard error values. The correlation coefficient (R) values obtained for both adsorption and desorption ranged from 0.998 to 0.999, and 0.991 to 1.000, respectively. The Mo values using the BET model at 33.8oC for both adsorption and desorption were 0.055, 0.055, 0.052, 0.049, 0.058, 0.055g H2O/g solid; and 0.057, 0.057, 0.052, 0049, 0.052, 0.057g H2O/g solid, respectively. At 50oC, the adsorption and desorption monolayer moisture values were 0.039, 0.047, 0.049, 0.049, 0.052, 0.058 gH2O/g solids; and 0.054, 0.047, 0.052, 0.052, 0.039, 0.052 gH2O/g solids, respectively. The study concluded that, the GAB model was more suitable in describing the sorption characteristics of Kamsa within the prescribed water activity and temperature ranges.
... al. [40], structural changes induced by temperature, or the process of moisture removal, can cause a decrease in the monolayer moisture content. This is as a result of reduction in the number of active polar sites due to chemical and physical changes [41]. Moreover, Labuza et. ...
The study was aimed at establishing storage stability indices of a traditional smoke dried product kamsa, produced from beef. The sample was produced using a standardized method and stored over a period of six months. Data for sorption studies was generated between the temperature ranges of 33.8oC to 50oC for adsorption and desorption using the gravimetric method. The data was analyzed using the Guggeinheim Anderson de Boer (GAB) and the Brunaeur Emmett Teller (BET) model equations. A nonlinear regression analysis method was used to evaluate the constants of the sorption equations. From the results using the GAB model, the monolayer moisture content (Mo) decreased from 0.021 to 0.008gH2O/g solids; the value of the constant K, increased from 0.587 to 1.052; and the value of CG decreased from 2.481 to 2.154. For desorption, the value of Mo decreased from 0.021 to 0.004g H2O/g solids; K increased from 0.587 to 1.035; CG increased from 2.173 to 2.646. The model gave low percent standard error values. The correlation coefficient (R) values obtained for both adsorption and desorption ranged from 0.998 to 0.999, and 0.991 to 1.000, respectively. The Mo values using the BET model at 33.8oC for both adsorption and desorption were 0.055, 0.055, 0.052, 0.049, 0.058, 0.055g H2O/g solid; and 0.057, 0.057, 0.052, 0049, 0.052, 0.057g H2O/g solid, respectively. At 50oC, the adsorption and desorption monolayer moisture values were 0.039, 0.047, 0.049, 0.049, 0.052, 0.058 gH2O/g solids; and 0.054, 0.047, 0.052, 0.052, 0.039, 0.052 gH2O/g solids, respectively. The study concluded that, the GAB model was more suitable in describing the sorption characteristics of Kamsa within the prescribed water activity and temperature ranges.
... Therefore, its high consumption can contribute to body mass gain. For this reason, its intake should be thought of in the context of a healthy diet, i.e., in moderate amounts only (20-25 g a day) [30,31]. ...
Chocolate is one of the most desired confectionery products in the world. Its production technology includes a series of processes conducted in appropriate conditions of the temperature and time. Most of these operations contribute to the degradation of valuable, natural and desired bioactive compounds; hence, producers search for novel technologies and solutions that would enable minimizing these losses. In 2012, the EFSA confirmed advantages of components within cocoa powder to health. This review is focused on analyzing the effect of particular stages of the production process, with consideration given over to the kind of raw ingredients of the finished product on the bioactive compound’s make-up in the products made in cocoa beans products subjected to the “traditional” process using both high and low temperatures. Due to the high temperature used during roasting, it is witch is one of the main processes affecting both the quality and sensory properties of the cocoa beans and products made from them. Each variety differs in size and beans color, resistance to the climatic resistance, and beans composition. Collected data allow us to establish which stages and which processes require further studies and analyses to be most useful for chocolate manufacturers not only in terms of the manufacturing repeatability of products, but also in developing an assortment of products having a positive effect on human health and well-being.
Couverture chocolate is highly demanded by consumers. Dark couverture chocolate is known as chocolate with high proportion of cocoa. There are several parameters that need to be considered to ensure the quality of this chocolate. One of the important chocolate qualities is hardness. In chocolate making, which is affected by the tempering process. Generally, the tempering process is carried out manually or automatically. Manual tempering is done by hand and is difficult to control the process temperature. Therefore, an automatic tempering machine was chosen in this study by controlling the tank and tempering temperatures. The purpose of the research was to optimize the combined effect between tank temperatures and tempering temperatures of the automatic tempering machine on the chocolate hardness parameter. Different ranges of the tank and tempering temperatures were applied to the chocolate mass processed in the machine. Chocolate hardness during storage was in the range 12.27 to 20.19 N/mm² in 45oC tank and 32.5oC tempering temperature. The optimum of the tank and tempering temperatures were 45oC-32.5oC (A), 48oC-32.5oC (B), and 50oC-31.5oC (C) which resulted in different k values and glossy appearances. The k values for A, B, and C were -0.00195; -0.0024; and -0.0031, respectively. While the determination coefficients for A, B, and C were 0.8970; 0.8887; and 0.9013, respectively.
In this study it was found that the complex microstructure of chocolate was modified by the addition of whey into original milk chocolate. A decreasing particle size diameter of the dispersed cocoa fat particles with increasing whey content followed by dynamic light scattering measurements was confirmed. Changes of the chocolate fat crystallinity through disrupting the highly ordered cocoa fat dense crystal aggregates to the less developed ones deformed by the inclusion of whey particles into the complex chocolate mass were simultaneously confirmed. These morphology changes affected the thermal and rheological behaviour of the studied samples by decreasing the melting peak temperature as well as Casson's plastic viscosity with increasing whey content. Furthermore, a gradual decrease of the hardness, thus reflecting the plasticising effect of the whey particles on the complex crystalline structure of the chocolate, was observed. The latter fact was also confirmed by the decreased acoustic emissions during chocolate breakage, thus indicating the change of the fracture process from brittle to more ductile.
The kinetics of cocoa butter crystallisation during solidification and resulting compactness of structure during storage for different chocolate model systems were investigated with respect to solid particle addition (sugar and cocoa particles) and pre-crystallization process (seeded/non-seeded). Confocal laser scanning microscopy (CLSM) was used to monitor microstructural evolution during solidification and image analysis were applied in order to quantify the kinetics. In order to quantify the compactness of structure during storage the migration rate of small-molecules was measured at different length scales. On the meso-scale, FRAP (Fluorescence Recovery After Photobleaching) was utilized to quantify local migration rate solely in the fat phase, whilst HPLC (High Performance Liquid Chromatography) measurements were performed to assess the global migration of same molecules on a macro scale. Both techniques were used in combination with microstructure characterization using CLSM and supported by differential scanning calorimeter melting curves for estimating cocoa butter polymorphism. During solidification, seeded samples tended to form multiple nucleation sites, inducing rapid growth of a crystal network. The non-seeded samples showed an altering structure, with some domains developing large spherical crystals while in other domains a more heterogeneous microstructure resulted. For the non-seeded samples, the impact of solid particles on the crystallization kinetics was also most pronounced. Both FRAP and HPLC analysis proved to generate relevant information of the effect of pre-crystallization and solid particles on compactness of structure during storage. FRAP-measurements gave detailed information of the hetero- or homogeneity in microstructure within the cocoa butter whilst the HPLC clearly showed the impact of solid particles. The combination of the two techniques revealed that a compact and homogeneous structure obtained through fast crystallization during solidification is required in order to retard global migration in confectionery systems. (c) 2011 Published by Elsevier B.V. Selection and/or peer-review under responsibility of 11th International Congress on Engineering and Food (ICEF 11) Executive Committee.
A combination of digital camera, computer and graphic software can provide a less expensive and more versatile technique to determine the changes of colour on chocolate's surface in fat bloom assessment compared to instrumental colour measurement. Both techniques were applied and compared to measure the colour profiles at various locations on the surface of bloomed chocolates. Pearson correlation coefficients and sample paired t-test on whiteness index (WI) and L*a*b* values were calculated. The value of WI of chocolate samples from instrumental technique was in the range of 35.8-44.3 with a coefficient of variance (CV) ranging from 0.0 to 0.9%. Meanwhile, digital image technique gave a WI value ranging from 35.1 to 45.1 with a CV from 0.1 to 14.2%, respectively. A highly significant correlation was found for the means of WI (R21/4 0.821) and L* (R2 1/4 0.788) values between instrumental and digital image technique. b* value of digital image also had significant correlation with the instrumental data (R21/4 0.756). However, there were significantly different measurements in the values obtained (p
Blooming or the migration of fat to the surface of chocolate results in color changes and development of non-uniform color patterns. These phenomena were assessed during storage of milk chocolate tablets (cycling temp. between 16 and 28 °C for 52 days) by a computer vision system and image analysis. Eight features were extracted from images (L*, a* and b* values, whiteness index, chroma, hue, % bloom and energy of Fourier). Major changes occurred after day 36 of storage, coincidental with visual perception. Initially, white specks emerged on the brown background but were superseded by the development of a whitish color extending over most of the surface. L*, whiteness index, a* and chroma correlated well with values taken with a commercial colorimeter (R2>0.70). Changes in image texture (energy of Fourier) followed a similar trend as color changes. The sequential forward selection strategy allowed correct classification of 97.8% of samples into four classes with only five features. The computer vision system has the capability to quantify overall changes as well as particular features over the whole chocolate surface thus enabling customization and standardization for quality assessment.
A storage trial was conducted to observe the effect of typical northern Australia climatic conditions on a military ration chocolate (RC). The results indicate that sensory quality decreased during storage; after seven days the chocolate was no longer of acceptable appearance. Deterioration in RC sensory quality was strongly correlated with decreases in visual acceptance (appearance) and increases in degree of blooming. Instrumental colour measurements were also strongly correlated with sensory ratings. Visual and microscopic observations provide evidence for movement of fat to and across the surface of the RC, behaviour that may be explained in terms of the phase transition theory of fat blooming. DSC thermographs provide evidence of a shift from predominantly polymorph form V in a fresh RC sample to a greater proportion of form VI in bloomed storage samples. The study provides a baseline against which efforts to improve the quality of RC may be evaluated.
a b s t r a c t The partial replacement of cocoa butter (CB) with milk fat (MF) strongly influences micro-scale topo-graphic evolution and fat phase crystallisation in milk chocolate. Adding MF reduces the incidence of large surface crystals and the number and diameter of amorphous, welled CB deposits ('cones'), with a concurrent decrease in initial surface roughness (p < 0.05) and rate of surface coarsening. Presence of MF also slows the solidification of the cones into disorganised crystalline masses. Finally, MF reduces the initial solid fat content, and slows the rate of change in whiteness index, as well as the form V to VI polymorphic transition. Fat crystal growth is accelerated by repeated temperature-cycling (26–29 °C) compared to isothermal conditioning (26 °C). However, cone hardening occurs more rapidly when isothermally-stored. Irrespective of fat composition and storage conditions, fat crystal growth, welling and ultimately fat bloom begin only at specific locations on the chocolate surface, suggesting that chocolate's microstructural heterogeneity is responsible for distinct surface fat crystallisation pathways.