Food and Bioprocess Technology

, Volume 5, Issue 2, pp 425–444

NIR Spectroscopy Applications for Internal and External Quality Analysis of Citrus Fruit—A Review

  • Lembe S. Magwaza
  • Umezuruike Linus Opara
  • Hélène Nieuwoudt
  • Paul J. R. Cronje
  • Wouter Saeys
  • Bart Nicolaï
Review Paper

Abstract

The global citrus industry is continually confronted by new technological challenges to meet the ever-increasing consumer awareness and demand for quality-assured fruit. To face these challenges, recent trend in agribusiness is declining reliance on subjective assessment of quality and increasing adoption of objective, quantitative and non-destructive techniques of quality assessment. Non-destructive instrument-based methods are preferred to destructive techniques because they allow the measurement and analysis of individual fruit, reduce waste and permit repeated measures on the same item over time. A wide range of objective instruments for sensing and measuring the quality attributes of fresh produce have been reported. Among non-destructive quality assessment techniques, near-infrared (NIR) spectroscopy (NIRS) is arguably the most advanced with regard to instrumentation, applications, accessories and chemometric software packages. This paper reviews research progress on NIRS applications in internal and external quality measurement of citrus fruit, including the selection of NIR characteristics for spectra capture, analysis and interpretation. A brief overview on the fundamental theory, history, chemometrics of NIRS including spectral pre-processing methods, model calibration, validation and robustness is included. Finally, future prospects for NIRS-based imaging systems such as multispectral and hyperspectral imaging as well as optical coherence tomography as potential non-destructive techniques for citrus quality assessment are explored.

Keywords

Non-destructive evaluation Near-infrared spectroscopy NIRS Citrus fruit Internal quality External quality Hyperspectral Multispectral Optical coherence tomography (OCT) X-ray computed tomography (CT) 

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Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  • Lembe S. Magwaza
    • 1
  • Umezuruike Linus Opara
    • 1
    • 2
  • Hélène Nieuwoudt
    • 3
  • Paul J. R. Cronje
    • 4
  • Wouter Saeys
    • 5
  • Bart Nicolaï
    • 5
  1. 1.Postharvest Technology Research Laboratory, Department of Horticultural ScienceStellenbosch UniversityStellenboschSouth Africa
  2. 2.Postharvest Technology Research Laboratory, Department of Food ScienceStellenbosch UniversityStellenboschSouth Africa
  3. 3.Department of Viticulture and Oenology, Institute for Wine BiotechnologyStellenbosch UniversityStellenboschSouth Africa
  4. 4.Citrus Research International, Department of Horticultural ScienceStellenbosch UniversityStellenboschSouth Africa
  5. 5.VCBT-MeBioS, Biosystems DepartmentKatholieke Universiteit LeuvenHeverleeBelgium

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