Research Article
Differentiation of Organic Cocoa Beans and Conventional Ones by Using Handheld NIR Spectroscopy and Multivariate Classification Techniques
Table 2
NIR wavelength band assignments.
| Wavelength (nm) | Functional group | Band assignments |
| 958 | OH | O-H 2nd overtone stretch of carbohydrate [54] | 973, 1005 | NH3 | N-H 2nd overtone stretch associated with fat (Chu [53]) | 986 | O-H | O-H 1st and 2nd overtones stretch of absorption peak of starch [54] | 1200 | C-H | C-H 1st overtones stretch related to proteins and starch [50] | 1280 | C-H | C-H 1st overtone bond stretching corresponding to fats and aromatic compounds [52] | 1483 | O-H | O-H 2nd overtone stretch corresponding moisture (Zhang et al. [53]) | 1417 | O-H | H2O band groups corresponding to weakly bounded water and aromatic compounds [43] | 1440, 1460 | O-H | O-H stretch 1st overtone of starch, water band, and sugars ([13]; Zhang et al. [46]) | 1608 | C=O | C-O from COOH typical of amines and acidity [55] |
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