Caracterização reológica e sensorial de sobremesa láctea diet contendo concentrado protéico de soro

• Autor(a) principal: Vidigal, Márcia Cristina Teixeira Ribeiro
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2873
• topic: Concentrado protéico; Textura; Análise sensorial; Protein concentrate; Texture; Sensory analysis; CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::CIENCIA DE ALIMENTOS

Addition of whey protein concentrate in non-fat dairy desserts is an alternative for consumers seeking low-calorie products, in addition to contain high nutritional value proteins. The objective of this work was to study the effect of whey protein concentrate (WPC) addition in non-fat dairy desserts, correlate instrumental and sensory measures and evaluate product acceptability. Four formulations of dairy dessert without fat were developed with different concentrations of WPS (0% (control), 1.5% (WPC1.5), 3.0% (WPC3.0) and 4.5% (WPC4.5)). The instrumental color of flan samples was evaluated and the parameters L* (brightness), a* (red-green component), b*(yellow-blue component), h* (hue) and C* (chroma) were obtained. The instrumental texture was evaluated by TPA and rheology. Rheological parameters were run at 10 and 25ºC. The sensory characterization of samples was carried out through Quantitative Descriptive Analysis (ADQ). The acceptance of the four samples was evaluated by ninety four consumers. Data were analyzed by Internal Preferential Map. Significant differences (p <0.0001) were detected in the values of the color parameters among the samples. Samples containing 3.0% and 4.5% of WPC were the darkest and yellowish. Concerning the instrumental texture, the formulations containing WPC (WPC1.5, WPC3.0 and WPC4.5) showed higher firmness, springiness, chewiness and gumminess values in relation to control sample. The samples showed time-dependent behavior and experimental data were fitted to the kinetic model proposed by Figoni & Shoemaker. The time-dependent parameters &#964; e (shear stress equilibrium value which is reached after a long enough shear time), &#964; o (initial shear stress), &#964; e - &#964; o (the amount of break-down structure for shearing) and Ki (kinetic constant of structural destruction) were obtained. Experimental data of flow curves were fitted to Hershel-Bulkley model and yield stress (&#964; o), flow index (nH) and apparent viscosity at 10s-1 (&#951;10) were obtained. The increase in WPC concentration raised the &#964; e - &#964; o, &#964; o and &#951;10. The attributes obtained by QDA for evaluation of the desserts were: color, firmness, resistance to cut, shine, consistence, gumminess, aroma and vanilla flavor. Significant differences (p<0.0001) were found among samples for all attributes. The formulations containing 3.0 and 4.5% of WPC showed higher intensity of all attributes of appearance, texture, flavor and aroma. Formulations with WPC1.5 and WPC3.0 were the most accept, confirming that addition of WPC in these concentrations favored the acceptability of the non-fat dairy dessert, providing characteristics of texture, flavor and aroma pleasant to the consumer. All instrumental color parameters correlated with the sensory color. Parameters of flow behavior &#964; o, KH and &#951;10, time-dependent parameters&#964; e- &#964; o and Ki and instrumental firmness (TPA) were correlated with sensory consistency. The correlation between instrumental and sensory measures provides practical information during the development and quality control of foods since the instrumental parameters are more easily obtained. Data obtained in this study led to the conclusion that a WPC concentration of 1.5% and 3.0% of WPC were effective, improving texture, flavor and aroma of dairy desserts, and, therefore, encouraging acceptability.