Rafael Silva Cadena

Manufacture of low-sodium Minas fresh cheese: Effect of the partial replacement of sodium chloride with potassium chloride

We investigated the effect of sodium reduction by partial substitution of sodium chloride (NaCl) with potassium chloride (KCl) on the manufacture of Minas fresh cheese during 21 d of refrigerated storage. Four treatments of low-sodium Minas fresh cheese were manufactured, with partial replacement of NaCl by KCl at 0, 25, 50, and 75% (wt/wt), respectively. The cheeses showed differences in the content of moisture, ash, protein, salt, and lipid contents, as well as on the extent of proteolysis and hardness throughout the storage period. However, no difference was observed among treatments within each storage day tested. The partial substitution of NaCl by KCl decreased up to 51.8% the sodium concentration of the cheeses produced. The consumer test indicated that it is possible to manufacture a low-sodium Minas fresh cheese that is acceptable to consumers by partial substitution of NaCl by KCl at 25% (wt/wt) in the salting step.

Reduced fat and sugar vanilla ice creams: Sensory profiling and external preference mapping

The aims of this study were (1) to map sensory attributes of vanilla ice cream with reduced fat and sugar, and (2) to determine drivers of liking by applying external preference mapping and reveal the relationship between descriptive attributes and hedonic judgments using the partial least squares method. Descriptive sensory profiles (n=11) and consumer test (n=117) of 6 samples of vanilla ice cream (3 traditional and 3 with reduced fat and sugar) were determined. The attributes brightness and sweet aftertaste for sample and creaminess (appearance and texture) and sweet aroma contributed positively to the acceptance of ice cream samples. The attributes aeration, powdered milk aroma and flavor, and white chocolate aroma and flavor contributed positively to the acceptance of the ice creams. The attributes hydrogenated fat aroma and flavor were responsible for the lower acceptance of samples. The reduction in fat and sugar did not necessarily cause a decrease in acceptance. The most important factors were selection of the appropriate sweetener system and the use of good quality raw material.

Effect of the inoculation level of Lactobacillus acidophilus in probiotic cheese on the physicochemical features and sensory performance compared with commercial cheeses.

The complex metabolism of probiotic bacteria requires several technological options to guarantee the functionally of probiotic dairy foods during the shelf life. This research aimed to evaluate the effect of the supplementation of increasing amounts of Lactobacillus acidophilus (0, 0.4, or 0.8 g/L of milk) on the physicochemical parameters and sensory acceptance of Minas fresh cheese. In addition, the sensory acceptance of probiotic cheeses was assessed using a consumer test and compared with commercial cheeses (conventional and probiotic). High counts (9.11 to 9.42 log cfu/g) of L. acidophilus were observed throughout the shelf life, which contributed to the maintenance of its probiotic status and resulted in lower pH values and greater production of organic acids. The probiotic cheeses presented lower scores for appearance, aroma, and texture compared with conventional cheeses. Internal preference mapping explained almost 60% of the total variation of the data and showed a large number of consumers concentrated near the conventional cheeses, demonstrating greater preference for these samples. The findings indicated that some negative sensory effects could occur when high level of supplementation with L. acidophilus is used in probiotic cheese processing.

Comparison of rapid sensory characterization methodologies for the development of functional yogurts

Functional food development is a long, complex, expensive and risky process. Methodologies that provide reliable information about the sensory characteristics of the developed products in short time frames can speed up the product development process and contribute to the success of the developed products in the marketplace. In this context, the aim of the present work was to compare three rapid methodologies for sensory characterization with descriptive analysis during the development of low-fat functional yogurts, enriched with probiotics and prebiotics. Eight low-fat probiotic yogurts enriched with a prebiotic ingredient were formulated following a 23 full factorial design with the following factors: sugar concentration, prebiotic ingredient and stabilizer concentration. A panel of 9 trained assessors evaluated samples using descriptive analysis. Besides, the yogurts were evaluated by 3 groups of 81 consumers using three rapid methodologies: check-all-that-apply (CATA) questions, projective mapping and polarized sensory positioning. The three rapid methodologies provided similar information on the main differences among samples. However, several differences can be highlighted. Sample configurations from CATA questions were the most similar to those provided by descriptive analysis, whereas projective mapping provided the least similar configurations. The three methodologies also differed in their ability to detect differences among samples due to formulation variables and the stability of sample configurations.

Monitoring the authenticity of low-fat yogurts by an artificial neural network

The growing consumption of low- and reduced-fat dairy products demands routine control of their authenticity by health agencies. The usual analyses of fat in dairy products are very simple laboratory methods; however, they require manipulation and use of reagents of a corrosive nature, such as sulfuric acid, to break the chemical bounds between fat and proteins. Additionally, they generate chemical residues that require an appropriate destination. In this work, the use of an artificial neural network based on simple instrumental analyses, such as pH, color, and hardness (inputs) is proposed for the classification of commercial yogurts in the low- and reduced-fat categories (outputs). A total of 108 strawberry-flavored yogurts (48 probiotic low-fat, 36 low-fat, and 24 full-fat yogurts) belonging to several commercial brands and from different batches were used in this research. The statistical analysis showed different features for each yogurt category; thus, a database was built and a neural model was trained with the Levenberg-Marquardt algorithm by using the neural network toolbox of the software MATLAB 7.0.1. Validation with unseen data pairs showed that the proposed model was 100% efficient. Because the instrumental analyses do not require any sample preparation and do not produce any chemical residues, the proposed procedure is a fast and interesting approach to monitoring the authenticity of these products.

Perfil sensorial e aceitação de bebida láctea achocolatada

Abstract The sensory profile of three commercial brands of milk chocolate beverage was obtained using the Quantitative Descriptive Analysis (QDA). Twelve descriptive terms, their definitions, and reference samples were generated by a selected and trained panel. The statistical analysis included the Analysis of Variance (ANOVA), Tukey’s Test for means, and Principal Component Analysis (PCA). Brand A showed strong sweetness taste, aroma, and caramel flavor, whereas the predominant characteristics of brand B were the brown color, viscosity, and very intense sandiness. Brand C differed from the others for presenting stronger aroma and milk flavor. An acceptance test was also performed to evaluate the samples thoroughly in terms of the intensity of the ideal sweetness and buying intention. All brands presented high acceptability, and there was no significant difference between them. Keywords: chocolate milk beverage; sensory analysis; descriptive quantitative analysis; acceptance; sweetness.