Model development for non-destructive determination of rind biochemical properties of 'Marsh' grapefruit using visible to near-infrared spectroscopy and chemometrics

Olaoluwa Omoniyi Olarewaju; Lembe Samukelo Magwaza; Helene Nieuwoudt; Carlos Poblete-Echeverría; Olaniyi Amos Fawole; Samson Zeray Tesfay; Umezuruike Linus Opara

doi:10.1016/j.saa.2018.10.027

Model development for non-destructive determination of rind biochemical properties of 'Marsh' grapefruit using visible to near-infrared spectroscopy and chemometrics

Spectrochim Acta A Mol Biomol Spectrosc. 2019 Feb 15:209:62-69. doi: 10.1016/j.saa.2018.10.027. Epub 2018 Oct 16.

Authors

Olaoluwa Omoniyi Olarewaju¹, Lembe Samukelo Magwaza², Helene Nieuwoudt³, Carlos Poblete-Echeverría⁴, Olaniyi Amos Fawole⁵, Samson Zeray Tesfay¹, Umezuruike Linus Opara⁵

Affiliations

¹ Discipline of Crop and Horticultural Sciences, School of Agricultural, Earth and Environmental Science, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, Pietermaritzburg, South Africa.
² Discipline of Crop and Horticultural Sciences, School of Agricultural, Earth and Environmental Science, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, Pietermaritzburg, South Africa. Electronic address: magwazal@ukzn.ac.za.
³ Institute for Wine Biotechnology and Department of Viticulture and Oenology, Stellenbosch University, Private Bag X1, Stellenbosch 7602, South Africa.
⁴ Department of Viticulture and Oenology, Faculty of AgriSciences, Stellenbosch University, Private Bag X1, Stellenbosch 7602, South Africa.
⁵ Postharvest Technology Research Laboratory, South African Research Chair in Postharvest Technology, Department of Horticultural Science, Faculty of AgriSciences, Stellenbosch University, Private Bag X1, Stellenbosch 7602, South Africa.

PMID: 30359850
DOI: 10.1016/j.saa.2018.10.027

Abstract

Rind biochemical properties play major roles in defence mechanisms against the incidence of rind physiological disorders of citrus fruit during cold storage. Hence, multivariate calibration models were developed to rapidly and non-destructively determine rind biochemical properties of citrus fruit from visible to near-infrared (Vis/NIR) spectra acquired by Vis/NIR spectroscopy using partial least square regression algorithm. To achieve optimum models for determination of each rind biochemical property, several mathematical pre-processing methods were explored, including no pre-treatment. However, special emphases were given to the best model statistics in terms of coefficient of determination (R²) and residual predictive deviation (RPD). Models were performed by critical examination of different wavelength ranges (visible, near-infrared and full regions) and combinations of fruit harvested from different production regions and acquired before (week 0) and after (week 9) cold storage. Results obtained showed excellent models for determining parameters such as sucrose (R² = 0.99 and RPD = 11.42), total flavonoids (R² = 0.99 and RPD = 12.37), and chlorophyll b (R² = 0.97 and RPD = 5.67). This study reported the first application of Vis/NIR and chemometrics in determining the rind biochemical properties of 'Marsh' grapefruit rapidly and non-destructively.

Keywords: 2, 6 Dichloroindophenol dye (PubChem CID: 13726); 2,2-Diphenyl-1-picrylhydrazyl (PubChem CID: 74358); Acetone (PubChem CID: 180); Antioxidants; Carbohydrates; Chemometrics; Ethanol (PubChem CID: 702); Gallic acid (PubChem CID: 370); Metaphosphoric acid (PubChem CID: 3084658); Multivariate analysis; Phytochemicals; Quercetin (PubChem CID: 5280343); Sodium Hydroxide (PubChem CID: 14798); Sodium carbonate (PubChem CID: 10340); Sucrose (PubChem CID: 5988); Vitamin C; Vitamin C (PubChem CID: 54670067); Water (PubChem CID: 962); d-Fructose (PubChem CID: 5984); d-Glucose (PubChem CID: 5793).

MeSH terms

Chlorophyll / analysis*
Citrus paradisi / chemistry*
Flavonoids / analysis*
Models, Theoretical*
Spectroscopy, Near-Infrared / methods*
Sucrose / analysis*
Wetlands*

Substances

Flavonoids
Chlorophyll
Sucrose
chlorophyll b