Hyperspectral imaging for non-destructive prediction of fermentation index, polyphenol content and antioxidant activity in single cocoa beans

Caporaso, Nicola; Whitworth, Martin B.; Fowler, Mark S.; Fisk, Ian D.

Abstract

The aim of the current work was to use hyperspectral imaging (HSI) in the spectral range 1000-2500 nm to quantitatively predict fermentation index (FI), total polyphenols (TP) and antioxidant activity (AA) of individual dry fermented cocoa beans scanned on a single seed basis. Seventeen cocoa bean batches were obtained and 10 cocoa beans were used from each batch. PLS regression models were built on 170 samples. The developed HSI predictive models were able to quantify three quality-related parameters with sufficient performance for screening purposes, with external validation R2 of 0.50 (RMSEP=0.27, RPD=1.40), 0.70 (RMSEP=34.1 mg ferulic acid g-1, RPD=1.77) and 0.74 (60.0 mmol Trolog kg-1, RPD=1.91) for FI, TP and AA, respectively. The calibrations were subsequently applied at a single bean and pixel level, so that the distribution was visualised within and between single seeds. HSI is thus suggested as a promising approach to estimate cocoa bean composition rapidly and non-destructively, thus offering a valid tool for food inspection and quality control.

Citation

Caporaso, N., Whitworth, M. B., Fowler, M. S., & Fisk, I. D. (2018). Hyperspectral imaging for non-destructive prediction of fermentation index, polyphenol content and antioxidant activity in single cocoa beans. Food Chemistry, 258, https://doi.org/10.1016/j.foodchem.2018.03.039

• Journal Article Type: Article
• Acceptance Date: Mar 10, 2018
• Online Publication Date: Mar 11, 2018
• Publication Date: Aug 30, 2018
• Deposit Date: Mar 22, 2018
• Publicly Available Date: Mar 22, 2018
• Journal: Food Chemistry
• Print ISSN: 0308-8146
• Electronic ISSN: 1873-7072
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 258
• DOI: https://doi.org/10.1016/j.foodchem.2018.03.039
• Keywords: Theobroma cacao; Hyperspectral chemical imaging; Cocoa quality; Antioxidant capacity; Phenolics; Near-infrared spectroscopy
• Public URL: https://nottingham-repository.worktribe.com/output/949152
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0308814618304692?via%3Dihub
• Contract Date: Mar 22, 2018