The influence of conching time on the sensory profile and consumer acceptance of milk chocolates enriched with freeze-dried blueberry (Vaccinium spp.).

Conching is a processing stage of industrial chocolate manufacture that is essential to the development of the sensory and rheological properties of the finished product. It promotes the physicochemical changes leading to flavor, aroma, and flowability refinement by continuously heating, aerating, shearing, and homogenizing chocolate mass during an extended time length. Conching duration is a key processing parameter that depends on the type of chocolate, the quality of primary ingredients, the conche's configuration, and the desired sensory outcome in the chocolate. Shorter cycles are often beneficial to manufacturers, due to increased productivity and reduced energy consumption, but they may be insufficient to fully develop chocolate's desired sensory properties. The present study aimed to shed light on the trade-off between product quality and process efficiency by assessing if varying conching durations were associated with statistically significant differences in the sensory profile and consumer acceptance of milk chocolates with freeze-dried blueberry. Samples were produced under an alternative method of conching prior to ball mill refining, with times investigated being 6, 12, 24, 36, 48, and 72 h, and were subsequently submitted to Quantitative Descriptive Analysis and consumer acceptance test. No statistically significant differences in either sensory profiles or consumer acceptance ratings of samples were observed, with the exception of hedonic values for aroma, indicating that a 6-h conching cycle was already enough to develop the sensory properties of the milk chocolate with freeze-dried blueberry. The feasibility of shorter conching times suggests a potential for energy saving and increased productivity in the production of milk chocolates following the conching prior to ball mill refining concept.

The role of conching in chocolate flavor development: A review.

Chocolate is an indulgent product whose consumption is mostly motivated by its alluring sensory properties. Among them, flavor stands as the key driver for consumer preference and purchase intention. Flavor is a complex multimodal perception whose discrimination depends mostly on the retronasal aromas associated with the presence of odor-active compounds in the matrix. The development of chocolate flavor relies on several factors, ranging from intrinsic properties of raw materials to formulation and processing conditions. As the last step of liquid chocolate manufacture, conching develops proper fluidity/texture and finetunes flavor, by means of intensive mixing and continuous heating of chocolate mass for several hours. Time and temperature are the main parameters determining the extent of conching effects upon flavor, despite factors such as ventilation, energy input onto chocolate mass, and configuration of conching machine being also relevant to some of the physicochemical mechanisms involved in flavor modification. Overall, conching impacts chocolate flavor by either changing the concentration of key odor-active compounds or modifying their distribution throughout the matrix, affecting their binding to other components and, ultimately, their rate of release during ingestion. The present review aims to gather evidence on the physicochemical transformations promoted by conching responsible for flavor enhancement and overall sensory quality of chocolates.

Effect of the homogenization process on the sensory and rheological properties in model system.

High pressure homogenization has been used for preparation and stabilization of emulsions and suspensions, promoting physical changes in products, such as viscosity change. However, its use in model systems for fruit nectar is innovative. This study aimed to evaluate the effect of the processing in high pressure homogenizer on the rheological behavior and the sensory attributes in model system of gellan gum. Gellan gum (0.05%), organic acids (0.3%), and sucrose (10%) were used to prepare the solutions, which were subsequently homogenized (0-control, 25 and 50 MPa) at 25°C. Rheological and sensory analyses were performed. The samples presented pseudoplastic behavior without residual stress and were characterized by the Ostwald-de-Waele model. The homogenization pressure (PH ) altered the viscosity of the model systems, reduced the consistency index and apparent viscosity, and increased the flow behavior index. The stimuli sour taste and viscosity differed among the parameters evaluated in the time-intensity analysis. No differences were observed for the maximum intensity of viscosity between the treated samples (25 and 50 MPa), which exhibited a similar temporal profile. Therefore, studies on the rheological and sensory behavior are fundamental to product development and process optimization. The present study shows new trends on the use of the high pressure homogenizer and the sensory profile in model systems that can be used for fruit nectar. This study evaluated the sensory attributes through the time-intensity analysis. The sensory data indicate that the homogenization pressure altered the viscosity perception, but did not alter the perception of the acid taste for the same organic acid used. Sensory as well as rheological data present new alternatives for product development. These findings are interesting for future research, equipment design, and process optimization.

Dynamic profiling of different ready-to-drink fermented dairy products: A comparative study using Temporal Check-All-That-Apply (TCATA), Temporal Dominance of Sensations (TDS) and Progressive Profile (PP).

Despite the several differences in ingredients, processes and nutritional values, dairy foods as yogurts, fermented milks and milk beverages are widely accepted worldwide, and although they have their sensory profiling normally covered by descriptive analyses, the temporal perception involved during the consumption are rarely considered. In this sense, the present work aimed to assess the dynamic sensory profile of three categories of fermented dairy products using different temporal methodologies: Temporal Dominance of Sensations (TDS), Progressive Profiling (PP), Temporal CATA (TCATA), and compare the results obtained. The findings showed that the different sensory characteristics among the products are basically related to their commercial identity. Regarding the methods, all of them collected the variations between samples with great correlation between data. In addition, to detect differences in intensities, TCATA showed to be the most sensitive method in detecting textural changes. When using PP, a balanced experimental design considering the number of attributes, time intervals, and food matrix must be weighed. The findings are of interest to guide sensory and consumer practitioners involved in the dairy production to formulate/reformulate their products and help them choosing the most suitable dynamic method to temporally evaluate them.

Consumers' perceptions toward 3 different fermented dairy products: Insights from focus groups, word association, and projective mapping.

Yogurts, fermented milk beverages, and fermented milks have great similarity and are widely accepted by Brazilian population, but the factors that influence their choice and consumption are unknown. In this sense, the present study aimed to identify the main aspects involved in consumers' perception of 3 different products, comparing the findings by using the 2 fast qualitative methods, word association and projective mapping, and a standard method, focus group. The tasks were performed by different participants through graphic stimuli (word association and projective mapping) and focus interviews (focus group). Results showed that all the 3 methodologies identified numerous intrinsic and extrinsic factors that influence the consumer choices regarding fermented dairy products. Major dimensions were closely related to the sensory aspects, emotional factors, perception of benefits, and composition, among others. It is noteworthy that the stimuli related to fermented milk beverages evoked rejecting responses, possibly due to the dissociation between information and consumers' expectation. Although minor differences were observed between the number and type of dimensions that were obtained, similar conclusions can be drawn from all 3 sensory methods, which shows the relevance of qualitative and projective methods for investigation of consumers' perception. These findings can help dairy companies to provide subsidies and guidelines for the reformulation of their products, marketing strategies, and improvement in the communication between producers and consumers from different fermented dairy products.

Consumer-based product characterization using Pivot Profile, Projective Mapping and Check-all-that-apply (CATA): A comparative case with Greek yogurt samples.

Product characterization has been a primary concern for the food industry, and methodologies based on consumers' perceptions have become popular and widely used by industries to replace classical methods. Although there are several studies on other methods, the potential of reference-based one such as Pivot Profile is still little explored. Therefore, the aims of this study were to characterize Greek yogurt samples according to consumers' perceptions using three different methodologies: Pivot Profile (PP), Check-all-that-apply (CATA), and Projective Mapping (PM), and to assess which method is easier for consumers to describe products. The rapid methodologies assessed were equally effective in characterizing the different samples; however, some drawbacks evidenced in the study can help in targeting and choosing the best method to perform the sensory characterization. Pivot Profile showed some advantages, bypassing some limitations presented by the other methods. In addition, its experimental versatility also allows for broad applications evidencing the PP technique as a promising tool for routine use. Some implications of using it were also discussed. We suggest the supplemental use of Multidimensional Alignment (MDA) as it shows more accurately the correlations between attributes and samples, especially in the case of PP data.

The Influence of the Rebaudioside A Content of Stevia (Stevia rebaudiana Bertoni) on the Determination of Sweetness Equivalence in Bittersweet Chocolates, Using the Time-Intensity Analysis.

The consumption of diet products has increased greatly in recent years. The objectives of the study were to develop a bittersweet chocolate added inulin and stevias with different rebaudioside A contents (60%, 80%, and 97%). Five chocolate samples were formulated with different sucrose concentrations to determine the ideal sucrose concentration for bittersweet chocolate. The use of just-about-right scale identified an ideal sucrose concentration of 47.5% (w/w). The sweetness equivalence in sugar-free bittersweet chocolates was determined by the time-intensity method by 14 selected and trained judges. The data collected during each session of sensory evaluation furnished the following parameters in relation to the sweet stimulus: Imax (maximum intensity recorded), Timax (time at which the maximum intensity was recorded), Area (area of time × intensity curve), and Ttot (total duration time of the stimulus). The time-intensity analysis indicated that the percentages of rebaudioside A did not interfere with the sweetness intensity of the sweetener stevia in bittersweet chocolate and there was no significant difference in the concentrations tested (0.16%, 0.22%, 0.27%) of each stevia, in relation to the parameters evaluated. In addition, the reduction in fat content did not alter the perception of the sweetness intensity of the samples. These results showed important information to research and development of chocolate products. Therefore, the use of the lowest stevia concentration tested (0.16%) is the most indicated for use, since this quantity was sufficient to reach the ideal sweetness of the product, so there was no point in adding more.

Novel and successful free comments method for sensory characterization of chocolate ice cream: A comparative study between pivot profile and comment analysis.

Rapid sensory profiling methods have gained space in the sensory evaluation field. Techniques using direct analysis of the terms generated by consumers are considered easy to perform, without specific training requirements, thus improving knowledge about consumer perceptions on various products. This study aimed to determine the sensory profile of different commercial samples of chocolate ice cream, labeled as conventional and light or diet, using the "comment analysis" and "pivot profile" methods, based on consumers' perceptions. In the comment analysis task, consumers responded to 2 separate open questions describing the sensory attributes they liked or disliked in each sample. In the pivot profile method, samples were served in pairs (consisting of a coded sample and pivot), and consumers indicated the higher and lower intensity attributes in the target sample compared with the pivot. We observed that both methods were able to characterize the different chocolate ice cream samples using consumer perception, with high correlation results and configurational similarity (regression vector coefficient=0.917) between them. However, it is worth emphasizing that comment analysis is performed intuitively by consumers, whereas the pivot profile method showed high analytical and discriminative power even using consumers, proving to be a promising technique for routine application when classical descriptive methods cannot be used.

Manufacture of probiotic Minas Frescal cheese with Lactobacillus casei Zhang.

In this study, the addition of Lactobacillus casei Zhang in the manufacture of Minas Frescal cheese was investigated. Minas Frescal cheeses supplemented with probiotic bacteria (Lactobacillus casei Zhang) were produced by enzymatic coagulation and direct acidification and were subjected to physicochemical (pH, proteolysis, lactic acid, and acetic acid), microbiological (probiotic and lactic bacteria counts), and rheological analyses (uniaxial compression and creep test), instrumental color determination (luminosity, yellow intensity, and red intensity) and sensory acceptance test. The addition of L. casei Zhang resulted in low pH values and high proteolysis indexes during storage (from 5.38 to 4.94 and 0.470 to 0.702, respectively). Additionally, the cheese protocol was not a hurdle for growth of L. casei Zhang, as the population reached 8.16 and 9.02 log cfu/g by means of the direct acidification and enzymatic coagulation protocol, respectively, after 21 d of refrigerated storage. The rheology data showed that all samples presented a more viscous-like behavior, which rigidity tended to decrease during storage and lower luminosity values were also observed. Increased consumer acceptance was observed for the control sample produced by direct acidification (7.8), whereas the cheeses containing L. casei Zhang presented lower values for all sensory attributes, especially flavor and overall liking (5.37 and 4.61 for enzymatic coagulation and 5.57 and 4.72 for direct acidification, respectively). Overall, the addition of L. casei Zhang led to changes in all parameters and affected negatively the sensory acceptance. The optimization of L. casei Zhang dosage during the manufacturing of probiotic Minas Frescal cheese should be performed.

Prebiotic Low Sugar Chocolate Dairy Desserts: Physical and Optical Characteristics and Performance of PARAFAC and PCA Preference Map.

The addition of prebiotic and sweeteners in chocolate dairy desserts opens up new opportunities to develop dairy desserts that besides having a lower calorie intake still has functional properties. In this study, prebiotic low sugar dairy desserts were evaluated by 120 consumers using a 9-point hedonic scale, in relation to the attributes of appearance, aroma, flavor, texture, and overall liking. Internal preference map using parallel factor analysis (PARAFAC) and principal component analysis (PCA) was performed using the consumer data. In addition, physical (texture profile) and optical (instrumental color) analyses were also performed. Prebiotic dairy desserts containing sucrose and sucralose were equally liked by the consumers. These samples were characterized by firmness and gumminess, which can be considered drivers of liking by the consumers. Optimization of the prebiotic low sugar dessert formulation should take in account the choice of ingredients that contribute in a positive manner for these parameters. PARAFAC allowed the extraction of more relevant information in relation to PCA, demonstrating that consumer acceptance analysis can be evaluated by simultaneously considering several attributes. Multiple factor analysis reported Rv value of 0.964, suggesting excellent concordance for both methods.

Microencapsulation of aspartame by double emulsion followed by complex coacervation to provide protection and prolong sweetness.

The objective of this work was to microencapsulate aspartame by double emulsion followed by complex coacervation, aiming to protect it and control its release. Six treatments were prepared using sunflower oil to prepare the primary emulsion and gelatin and gum Arabic as the wall materials. The microcapsules were evaluated structurally with respect to their sorption isotherms and release into water (36°C and 80°C). The microcapsules were multinucleated, not very water-soluble or hygroscopic and showed reduced rates of equilibrium moisture content and release at both temperatures. FTIR confirmed complexation between the wall materials and the intact nature of aspartame. The results indicated it was possible to encapsulate aspartame with the techniques employed and that these protected the sweetener even at 80°C. The reduced solubility and low release rates indicated the enormous potential of the vehicle developed in controlling the release of the aspartame into the food, thus prolonging its sweetness.

Sensory acceptance and survival of probiotic bacteria in ice cream produced with different overrun levels.

The effect of different overrun levels on the sensory acceptance and survival of probiotic bacteria in ice cream was investigated. Vanilla ice creams supplemented with Lactobacillus acidophilus were processed with overruns of 45%, 60%, and 90%. Viable probiotic bacterial counts and sensory acceptance were assessed. All the ice creams presented a minimum count of 6 log CFU/g at the end of 60 d of frozen storage. However, higher overrun levels negatively influenced cell viability, being reported a decrease of 2 log CFU/g for the 90% overrun treatment. In addition, it was not reported an influence about acceptability with respect to appearance, aroma, and taste of the ice creams (P > 0.05). Overall, the results suggest that lower overrun levels should be adopted during the manufacture of ice cream in order to maintain its probiotic status through the shelf life.

Sensory Analysis: Relevance for Prebiotic, Probiotic, and Synbiotic Product Development.

Sensory analysis represents a decisive step during the various stages of food product development. For probiotic, prebiotic, and synbiotic foods, which have shown continuous and significant consumption in the functional food category, the choice of an appropriate technique allows obtaining relevant sensory information that contributes to consumer acceptance. This review focuses on the importance of sensory analytical techniques in prebiotic and probiotic food product development. Examples of the most known sensory methodologies applied to these important functional foods are presented, as well as some considerations about consumer attitudes that can influence acceptance of these products. Moreover, applications of such techniques on functional product evaluation are provided.