Prediction of internal quality of citrus fruits by NIR spectroscopy

Abstract

Consumer perception and satisfaction regarding fruit quality is an important issue in marketing. However, there is a lack of objective information that will allow consumers to choose fruit of a desired quality. Good correlations, well established in the literature, exist between soluble solid content and consumer acceptance of several fruit. Commercial application of near infrared spectroscopy (NIR) to fruit sorting by soluble solids was first initiated in Japan in 1990, and this technology has been applied to pack-house fruit sorting lines for sweetness of citrus, apples, pears and peaches, since the mid 1990s in Japan, and more recently in other countries. At present, NIR technology applied to nondestructive measurement of fruit quality is in development. Commercially available instruments for these applications are few and scientific evaluation of calibration models for the measurement of the most important fruit internal quality parameters is needed. NIR technology has the potential to become a suitable instrument, not only to sorting citrus fruit by some quality parameters but also to develop 'electronic tasters' based on the correlation among NIR measuring and sensory analysis. As well, the direct use of portable instruments by consumers for purchasing decision could become of interest. A review is done in this work on the state of the art of NIR applied to citrus quality prediction.