The data and findings discussed here come from the cited paper and do not represent test results from VISPEK equipment.
Direct measurement of the whole bean eliminates the need for grinding, but inhomogeneities in the cocoa bean shell and sample can also change the signal. This study compared whole beans and shelled powder samples of commercially available dry cocoa beans, as well as desktop and portable instruments, to help determine the predicted cost of convenient sample preparation.
Summary
The study used conventional physical and chemical analysis of commercial cocoa beans as a reference to establish reflection models for whole beans and shelled powder samples. In the portable near-infrared branch, the cross-validation performance of protein, dry matter and fat was better for powder samples, while the results for whole beans were weaker. Desktop branch scores are not transferable to portable devices, and small sample verification does not represent full flavor or transaction quality.
(AI-generated conceptual illustration for context; it is not data from the paper, a photograph of the research equipment, or a VISPEK product diagram.)
Why It Matters
Comparisons between desktop and portable, whole beans and powder samples can help cocoa procurement choose an executable route based on on-site conditions.
Methods and Reference Measurements
Whole commercial dry cocoa beans and dehulled powder samples were randomly selected. Reflectance spectra were collected with a benchtop instrument (850–2500 nm) and a portable instrument (900–1680 nm). The portable instrument used a circular contact window, and three readings were averaged. Conventional physicochemical tests served as references. Full-spectrum and wavelength-selected MPLS/PCR models were compared using five-fold cross-validation.
Wavelengths and Acquisition Parameters
| Band/parameter | Original meaning and usage instructions |
|---|---|
| 850–2500 nm | Desktop DS2500 range |
| 900–1680 nm | Portable PoliSPEC Scope |
| 765 nm；460／530 nm | Independent reference for polyphenol color rendering and color index, non-NIR input |
Key Findings
Table 3: In the 900-1680 nm portable PoliSPEC powder model, protein and dry matter are both R²cv=0.79, RPD=2.17; fat R²cv=0.82, RPD=2.34. Table 2 The portable results of whole beans are weak, with protein R²cv=0.56 and dry matter 0.66. The above is cross-validation; higher scores from the desktop full spectrum or desktop crop models cannot be moved to the portable branch.
Limitations and Interpretation
The 56 commercially sourced samples are still limited; the reference color index does not equate to full flavor or trade quality indicators.
Band and model boundaries: Only 900-1680 nm portable PoliSPEC independent MPLS/PCR and cross-validation results are included; 850-2500 nm desktop results cannot be borrowed.
Image copyright belongs to the paper’s original authors. License: CC BY 4.0.
Source Paper
Forte M, Currò S, Van de Walle D, Dewettinck K, Mirisola M, Fasolato L, Carletti P. (2022). Quality Evaluation of Fair-Trade Cocoa Beans from Different Origins Using Portable Near-Infrared Spectroscopy (NIRS). Foods (Basel, Switzerland). https://doi.org/10.3390/foods12010004
Contact Us
Whether portable equipment can be used for similar detection needs to be evaluated based on samples and experimental conditions, and the specific effect still needs to be verified through actual testing. Welcome to contact VISPEK to exchange your sample and testing needs, jointly evaluate experimental plans, and explore the feasibility of using our company's equipment for actual measurement and verification.
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VISPEK products shown for illustration; these were not the devices used in the cited study.