Non-invasive detection of internal flesh breakdown in intact Palmer mangoes using time-domain nuclear magnetic resonance relaxometry

The advent of new compact, bench-top, inexpensive and more user-friendly low-field nuclear magnetic resonance spectrometers in the last decade opens new opportunities for new non-destructive and non-invasive analytical methods to study physical-chemical properties of the internal parts of fruits. Correlations of the internal chemical environment with NMR relaxometry signals is an important parameter for food quality control, however, differently from controlled processed food, internal fruits environment has not always a straight correlation with relaxometry signals. In this paper we demonstrate that Time Domain-NMR signals combined with chemometrics analysis are a powerful tool for studies and industrial control of the internal quality of Palmer mangoes, providing tools to evaluate the fruit ripeness and internal flesh breakdown, which are highly difficult to be detected in intact fruits by other analytical methods. Results shows that combining transverse relaxation time distribution with Principal Component Analysis it is possible to classify three groups: unripe mangoes, ripe mangoes, and ripe mangoes with physiological defects.