Magnetic Resonance Imaging for Nondestructive Analysis of Wine Grapes

Abstract

Magnetic resonance imaging (MRI) was used to study the growth and ripening of grape berries for three varieties. The results show that this technique allows the visualization of internal characteristics of berries using noninvasive procedures in order to obtain the volume and degrees Brix distribution within a cluster. Samples of Cabernet Sauvignon, Carmenère, and Chardonnay varieties collected over the 2002 season were analyzed. Calibration models were developed to correlate soluble solids (degrees Brix) against spin-lattice relaxation time t(1) and spin-spin relaxation time t(2). The correlation of degrees Brix and t(1) was R(2) = 0.75 for Cabernet Sauvignon, R(2) = 0.8 for Carmenère, and R(2) = 0.65 for Chardonnay. In the case of t(2) the correlation was significantly lower. Reconstruction techniques for the three-dimensional representation of clusters were developed, allowing an interactive visualization of the bunches. The method also provides volume measurements of single berries and their distribution within the cluster with an accuracy of 3% and R(2) = 0.98. These results show the potential of MRI in the wine industry for both monitoring and research. Not only does it provide quantitative information about the berries such as volume and degrees Brix distributions, but it can also be used to support the sampling procedures by providing a better cluster characterization.

Potential uses of LF‐NMR and MRI in the study of water dynamics and quality measurement of fruits and vegetables

“…Fruit softening due to variations in the fruit tissue's structure during storage was depicted through changes in the tissue's water status (Le´tal, ). In addition, MRI has been implemented in quantitative assessments and studies of physiological changes such as fruit firmness and solid solubility (an attribute associated with the status of water) during maturation and storage as a function of relaxation times (Andaur, Guesalaga, Agosin, Guarini, & Irarrázaval, ; Zhou & Li, ). The percentage of soluble solids is generally utilized as a measure of ripeness since in the process of ripening the starch breaks down into sugars (Marigheto, Wright, & Hills, ).…”

Non-destructive technologies for fruit and vegetable size determination – A review

“…9). Andaur et al (2004), who used MRI to measure wine grapes, developed reconstruction techniques for 3-D representation of berry clusters. Size distribution of berries is important to predict extractability in grapes because the wine-making parameter of extractability is a function of the skin-to-flesh ratio, so it is inversely proportional to the volume of the berries.…”

Metabolic and histopathological alterations of Jatropha mosaic begomovirus-infected Jatropha curcas L. by HR-MAS NMR spectroscopy and magnetic resonance imaging

“…MRI provides a high promise in understanding physiological state and function of tissues based on water distribution and highly resolved spatial information about anatomy and water distribution and magnetic environment of water in plant tissues (Chen et al 1989;Clark et al 1997;Donker and Van 1999). The method has been used to quantitatively assess and study physiological changes such as Wrmness and solubility of solids in fruit during maturation and storage as a function of the relaxation times (Andaur et al 2004). The investigations on metabolic changes with respect to anatomical alterations due to viral infection and nature of spread of disease in J. curcas have not been studied earlier.…”