Full text
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| Author(s): |
Pedro Renann Lopes França
Total Authors: 1
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| Document type: | Master's Dissertation |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia de Alimentos |
| Defense date: | 2021-03-19 |
| Examining board members: |
Juliana Azevedo Lima Pallone;
Rafael Augustus de Oliveira
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| Advisor: | Louise Emy kurozawa |
| Abstract | |
Red beet (Beta vulgaris L.) has a high nutritional value and is usually consumed after being processed, for example, dried. Despite its benefits, its quality is reduced in different aspects during drying process. Thus, this work aimed to analyze the drying process and the quality of red beet cubes subjected to hot air drying (HAD), in terms of total betalain content (BT), color, and shrinkage, using infrared thermography (IRT), computer vision system (CVS), and near infrared spectroscopy (NIR) in portable equipment. The drying kinetics at different temperatures (40, 50, 60, and 70°C) was well described by the Page and Fick models, considering the shrinkage. A probable formation of a dry and rigid layer around the product dried at 70°C may have contributed to lower moisture removal when compared to the sample dried at 60°C. The cubes heated almost uniformly during the drying process until the thermal equilibrium was achieved. At the end of the drying process, betalain retention was 49.8±1.6%; 43.7±1.7%; 35.3±3.3%; 25.7±3.1%, for temperatures of 40, 50, 60 and 70°C, respectively. The kinetic and thermodynamic parameters indicated showed that the increase in temperature provided a greater loss of BT due to a favorable formation of the activated complex in the degradation reaction. Using a computer vision system (CVS), the increase in temperature also promoted greater color deterioration of the product dried at 70°C. The color variation in terms of L*, chroma, hue angle, and ?E was well related to the degradation of BT by a multivariate linear regression, with R2 of 0.90. The cubes showed a shrinkage of 79.4±1.4%; 80.7±2.0%; 82.0±0.5%, and 85.4±0.3% at temperatures of 40, 50, 60, and 70°C, respectively. Regardless of temperature, the shrinkage behavior was very close, in which the Suzuki model described it well. Thus, in general the temperature of 40°C provided lower quality changes in the red beet. The use of portable NIR was effective in the analysis of BT and moisture contents, obtaining a predictive model of reduced PLSR with values of R2Cal, R2Pred, and RPD of 0.909, 0898, and 3.16 for moisture content; and 0.811, 0.191, and 2.19 for BT content. Therefore, the imaging tools (IRT and CVS) and the portable NIR were efficient in the evaluation of the drying of red beet cubes, representing important tools for the in situ control of its drying (AU) | |
| FAPESP's process: | 19/23032-1 - Study of the relation between the formation of glass transition zones and betalain loss during convective drying of beetroot |
| Grantee: | Pedro Renann Lopes de França |
| Support Opportunities: | Scholarships in Brazil - Master |