Estudo da influência do sabor e da cor na percepção da textura estaladiça em snacks

Mestrado em Engenharia Alimentar - Instituto Superior de Agronomia

Crispness is one of the most important sensory attributes related with the quality of low moisture solid food products. It can be defined as the perceived force through which the products are separated into two or more distinct pieces during a single bite with the incisors, emitting a characteristic noise. Most of the commercialized snacks have different colors, tastes and smells. The taste and smell have been shown to interact and the texture impact on taste has been studied. It is well known that the color greatly impacts the ability of people to identify food. The aim of this work was to create healthier snacks (non-fried), and to evaluate the influence of the color, taste and smell in the perception of crispness, sensory hardness and consumers’ acceptance. There are several ways to obtain crispness in snacks, but the more relevant are dehydration, extrusion and microwave expansion. In the present study, the method used to prepare snacks was to mix Tapioca flour with water, to cook and then dehydrate this mix in a food dehydrator and in a microwave. The colorants used were, blue, green, orange and red, and the tastes were the four basic ones - sweet, acid, bitter, salty - and the umami. The colorants were added to the dough before cooking and the tastes by submersion in a water solution containing each taste. After many attempts, it was not possible to fix the aromas to the snacks. The snacks were analyzed physically with Kramer-shear tests with a texturometer, and sensory by mostly an untrained consumers’ panel using descriptive scales with discontinuous structure in the analytical testing. The water content of the snacks was also evaluated. Statistical analysis of the results (moisture content, Kramer-shear tests and sensory analysis) was carried out with the SPSS program (one-way analysis of variance), and Statistica, version 5, was used to handle multivariate analysis of data. The moisture content data indicated that, after exposure to the microwave, the snacks presented significantly different water amounts, which indicates that they dehydrate in different ways, maybe because of their structure or different shapes. The Kramer-shear tests results showed that only the colored snacks had different peak numbers indicating that they were slightly different according to crispness. The sensory analysis results indicated that the colors affected only the acceptance while the tastes influenced the hardness perception and also the acceptance by the consumers. The hardness measured by instrumental texture analysis showed to be related with the sensory hardness detected by the consumers. Some of the panelists were influenced by the snack color, feeling tastes related with the colors but absent in the samples. For example, the red color was related to the perception of strawberry taste and the green color to mint taste. The multivariate analysis (principal component analysis and cluster analysis) of data, including Kramer-shear tests and sensory analysis results, showed two distinct groups: one containing the snacks of different tastes, except the bitter sample, and the other with the snacks of different colors plus the bitter snack. The snacks preferred by the consumers were those with the orange color and the salty or sweet snacks. The panelists identified the samples with the bitter taste, with the green color and non-colored snacks as the hardest. Therefore, these samples were rejected by the consumers. The colored snacks were considered crispier and the flavored snacks as less hard, except the bitter ones.