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.

Application of time-intensity analysis in model system submitted to homogenization.

The use of the high pressure homogenizer has been studied in fruit juices, but researches in model system for application in fruit nectar are scarce. Therefore, it is necessary to evaluate the application of these technologies and how the homogenization pressure (PH) can interfere in the sensorial profile of the samples. To prepare the solutions we used guar gum (0.1%), organic acids (0.3%), and sucrose (10%), which were later homogenized (0-control, 25 and 50 MPa) at 25 ℃. The rheological behavior and the temporal profile of the samples were evaluated. The model systems presented pseudoplastic behavior without residual tension and were fitted to the Ostwald-de Waele model. The consistency index reduced and the flow behavior index increased with processing. Apparent viscosity also decreased due to homogenization. In the time-intensity sensorial analysis, it was observed that the samples differed among the evaluated parameters, demonstrating that the samples with tartaric acid presented higher intensity for the sour taste. However, for sweetness, no change was observed. In the viscosity attribute, the model systems presented similar temporal profiles. Therefore, it was noted that the homogenization process favored a greater temporal profile of sour taste, making sensory perception more lasting in a model system for fruit nectar.