Fourier transform near infrared diffuse reflectance spectroscopy and two spectral acquisition modes for evaluation of external and internal quality of intact pomegranate fruit

Ebrahiema Arendse, Olaniyi Amos Fawole, Lembe Samukelo Magwaza, Helene Nieuwoudt, Umezuruike Linus Opara

Research output: Contribution to journalArticlepeer-review

32 Citations (Scopus)

Abstract

Fourier transform near infrared (FT-NIR) diffuse reflectance spectroscopy as a non-destructive method for the development of calibration models has been investigated as a means of assessing the quality of whole pomegranate fruit. FT-NIR diffuse reflectance spectrometers with different spectral acquisition modes were evaluated using direct contact between the sample and the integrating sphere (IS), or by a contact-less measurement using an optic fibre coupled emission head (EH) to scan fruit over a distance of 170 mm. Fruit weight, firmness and colour components (a* Chroma, hue angle), total soluble solids (TSS), pH, titratable acidity (TA), sugar to acid ratio (TSS:TA), BrimA, total phenolics, total anthocyanin and vitamin C. The best prediction statistics obtained from calibration models of the EH were firmness (R2 = 83.0, residual predictive deviation (RPD) = 2.43), fruit colour components (a*: R2 = 90.9, RPD = 3.34); Chroma: R2 = 83.0, RPD = 2.43, TSS (R2 = 78.1, RPD = 2.17), TA (R2 = 76.8, RPD = 2.12), BrimA (R2 = 76.2, RPD = 2.08), total phenolics (R2 = 88.0, RPD = 2.91) and vitamin C (R2 = 76.2, RPD = 2.06). The best prediction obtained from calibration models of IS were colour component Hue (R2 = 83.9, RPD = 2.50), TSS:TA (R2 = 86.8, RPD = 2.72) and total anthocyanin (R2 = 62.6, RPD = 1.64). Overall, good prediction was observed for both the EH and IS; however, better prediction performance was obtained with the EH which gave the best prediction for 9 of the 13 quality parameters evaluated. These findings have demonstrated that the EH (a contactless option of the Matrix-F) can be implemented as an online tool for the analysis of pomegranate fruit quality.

Original languageEnglish
Pages (from-to)91-98
Number of pages8
JournalPostharvest Biology and Technology
Volume138
DOIs
Publication statusPublished - Apr 2018
Externally publishedYes

Keywords

  • FT-NIR
  • Fruit quality
  • Non-destructive measurement
  • Partial least squares
  • Punica granatum L
  • Sensory quality
  • Total phenolics
  • Vitamin C

ASJC Scopus subject areas

  • Food Science
  • Agronomy and Crop Science
  • Horticulture

Fingerprint

Dive into the research topics of 'Fourier transform near infrared diffuse reflectance spectroscopy and two spectral acquisition modes for evaluation of external and internal quality of intact pomegranate fruit'. Together they form a unique fingerprint.

Cite this