Application of near Infrared Spectroscopy to the Quality Control of Citrus Fruits and Mango
Author
Blasco, José; Lorente, Delia; Cortés, Victoria; Talens, Pau; Cubero, Sergio; Munera, Sandra; Aleixos, NuriaDate
2016Cita bibliográfica
Blasco, J., Lorente, D., Cortes, V., Talens, P., Cubero, S., Munera, S., & Aleixos, N. (2016). Application of near infrared spectroscopy to the quality control of citrus fruits and mango. NIR news, 27(7), 4-7.Abstract
NIR spectroscopy is a proved tool to measure the optical properties of the samples, which are
related to their chemical and textural properties. This technology can be used for determining
the internal and external quality of fruits. Accordingly, many studies have been reported for
long time to assess the quality of different fresh fruits by using reflectance measurements
acquired with visible-NIR spectroscopy. We have been working on the estimation of the quality
of fruits using computer vision for more than twenty years, always focused on problems that
affect the local industry. As the region of Valencia (Spain) is one of the main producers and
exporters of citrus fruits worldwide, most of our research has been focused on this fruit,
especially developing fast and reliable methods to detect defective fruit in quality control lines1.
Nevertheless, our group have been carried out also other studies to determine the internal
quality in other fruits with commercial interest for our region, such as, mangoes cv. ‘Osteen’,
nectarines cv. 'Big Top' and cv. 'Magique', and persimmon cv. ‘Rojo Brillante’.
Nowadays, the fruit producers demand automated systems to detect fruits with decay lesions
that are not visible at early stages but that can spread the infection to other fruits during storage
or shipping. In the case of citrus fruits, this is the most economically important postharvest
disease of citrus worldwide. Detection of these diseases may considerably help to correctly
discriminate and classify different fruit lots and take important decisions, based on fruit quality,
about postharvest handling and final produce destination. However, the detection of rotten fruit
in citrus packing-lines is performed manually, using the naked eye under ultraviolet (UV) light
that induces visible fluorescence, what it is harmful for the workers. New automatic devices
using UV or hyperspectral imaging2 are being investigated as possible alternatives to manual
inspections. However, industry’s demands for innovative tools for rapid and cost-effective early
detection have spurred considerable interest among researchers on the application of nearinfrared
spectroscopy (NIRS) on citrus fruit quality monitoring as stated in the review carried
out by Magwaza et al.3.
Moreover, Spain is the main European producer of subtropical fruits and in particular the southwest
region has a large potential for the production of Mango fruit. In the past, external quality,
related to the skin colour, fruit size and shape, free from defects and the absence of decay were
the most common quality determinants, but nowadays other organoleptic characteristics related
to the internal quality play an important role in the consumer’s decision. Hence, another aim
was to investigate the potential of visible and NIR to determine the internal quality of mango cv.
‘Osteen’, the main variety of mango grown in Spain.