Use of non-destructive instrumental techniques to evaluate effects of gamma irradiation, quality and sensory attributes in orange juice

• Autor(a) principal: Bizzani, Marilia
• Data de Publicação: 2021
• Tipo de documento: Tese
• Idioma: eng
• Título da fonte: Biblioteca Digital de Teses e Dissertações da USP
• Texto Completo: https://www.teses.usp.br/teses/disponiveis/11/11141/tde-21052021-094731/
• topic: Análise sensorial; Chemometrics; Citros; Citrus; Conservação por irradiação; Irradiation conservation; MIR; MIR; NIR; NIR; Quimiometria; RMN-DT; Sensory analysis; TD-NMR

The citrus sector is one of the most traditional in Brazilian agribusiness and accounts for 34% of orange production worldwide. However, together with the competitiveness of the current market, orange production has been greatly impacted by climatic variations. In this context, we notice the importance of tools that analyze orange juice on a large scale and quickly in scenarios of high productivity, as well as ensuring quality control in times of low product supply. Related to the quality of orange juice, there are some factors such as the use of conservation methods and the presence of sensory attributes. Among food preservation methods, irradiation can be an alternative in the conservation of fruit juices, but measuring the effects of irradiation is a challenge. Regarding the sensory attributes, the method of quantitative descriptive analysis (ADQ) is capable of providing a complete sensory description of a product, however it requires a long period of training of tasters. In this context, instrumental analyzes such as time domain nuclear magnetic resonance (TD-NMR) and medium-infrared (MIR) and near (NIR) spectroscopy have been explored in intact fruits and juices demonstrating a correlation with quality parameters associated with sensory perception and control of processes. However, clean, fast and non-destructive technologies in combination with irradiation processes and sensory attributes were weakly explored in the literature. Therefore, the present study discusses in the first chapter: the use of non-destructive instrumental methods such as TD-NMR, MIR and NIR to analyze irradiated orange juice. In the following chapters, the studies were directed to assess the quality of orange juice using the ADQ method and its relationship with instrumental methods (TD-NMR, MIR and NIR). The results demonstrated a good performance in the classification of non-irradiated and irradiated samples using the spectral data of MIR and TD-NMR. The study of the relationship between non-destructive instrumental methods and ADQ showed better performance in the classification models for the descriptors yellow, natural flavor, aroma freshness, aroma and flavor cooked with predictive skills valid between 70% and 87% using the MIR spectral data. On the other hand, the classification models based on TD-NMR data reached 79% of correctness in the classification of yellow color and 72% in the body classification of orange juice. Thus, the extensive study of the analytical methods of NMR-DT, MIR and NIR showed great advances in the field of study of the quality of fruit juices and quick and clean analyzes coupled with multivariate statistical techniques for food analysis.