Emprego da Ressonância Magnética Nuclear no domínio do tempo para estudo de matrizes vegetais

Abstract

Time-Domain Nuclear Magnetic Resonance (TD-NMR) is a non-destructive and non-invasive analytical technique, well-established in several industrial and scientific sectors. This work presents a literature review on the application of TD-NMR for the analysis of plant matrices and plant-based products, addressing its instrumental evolution, the fundamental concepts of the technique, contemporary instrumentation, the pulse sequences employed, and its main applications. Different magnet formats were explored, such as parallel plates, Halbach cylinders, and portable MOUSE-type scanners, which allow for analyses ranging from laboratory routine to in-process measurements. Pulse sequences, such as Carr-Purcell-Meiboom-Gill (CPMG) and Inversion-Recovery (IR), are discussed as tools for measuring 𝑇2 and 𝑇1 relaxation times, which correlate with the macroscopic properties of the samples. The review details the application of TD-NMR in the analysis of oils and fats to determine oil content, solid fat content (SFC), detect adulterations, and monitor oxidative stability. In the study of fruits, the technique is employed to assess the degree of maturation, detect adulterations in juices, and quantify the crystallinity of sugars. Finally, the application of the technique in the analysis of wood is explored to characterize the different water compartments and evaluate the effectiveness of thermal and chemical modification treatments. TD-NMR establishes itself as a fast, robust, and sustainable tool for quality control in the most diverse sectors, especially the agro-industry, providing simple and powerful solutions.