Differentiation of Organic Cocoa Beans and Conventional Ones by Using Handheld NIR Spectroscopy and Multivariate Classification Techniques

Table 3

Classification models with preprocessing algorithms for cocoa bean samples.

Models	Preprocessing	PCs	Evaluation	Performance (%)
				Calibration set	Prediction set
RF	Raw	3	Accuracy	67.79	67.31
			Sensitivity	69.23	69.23
			Specificity	66.35	65.38
			Efficiency	67.77	67.28
	MC	7	Accuracy	85.58	88.46
			Sensitivity	82.69	84.62
			Specificity	88.46	92.31
			Efficiency	85.53	88.38
	FD	7	Accuracy	89.90	88.46
			Sensitivity	90.65	91.30
			Specificity	89.11	86.21
			Efficiency	89.88	88.72
	SD	9	Accuracy	96.15	98.08
			Sensitivity	94.95	96.77
			Specificity	97.25	100.00
			Efficiency	96.09	98.37
KNN	Raw	3	Accuracy	65.38%	69.23
			Sensitivity	71.29%	62.07
			Specificity	59.81%	78.26
			Efficiency	65.30%	69.70
	MC	5	Accuracy	79.81	82.69
			Sensitivity	82.86	76.00
			Specificity	76.70	88.89
			Efficiency	79.72	82.19
	FD	5	Accuracy	80.77	80.77
			Sensitivity	75.76	83.87
			Specificity	85.32	76.19
			Efficiency	80.40	79.94
	SD	5	Accuracy	91.35	92.31
			Sensitivity	87.27	95.00
			Specificity	95.92	90.63
			Efficiency	91.49	92.79
LDA	Raw	3	Accuracy	69.71	69.23
			Sensitivity	72.38	64.00
			Specificity	66.99	74.07
			Efficiency	69.63	68.85
	MC	5	Accuracy	84.13	78.85
			Sensitivity	86.14	86.21
			Specificity	82.24	69.57
			Efficiency	84.17	77.44
	FD	5	Accuracy	78.85	80.77
			Sensitivity	83.65	88.46
			Specificity	74.04	73.08
			Efficiency	78.70	80.40
	SD	5	Accuracy	90.38	98.08
			Sensitivity	89.42	100.00
			Specificity	91.35	96.15
			Efficiency	90.38	98.06
PLS-DA	Raw	3	Accuracy	77.88	78.85
			Sensitivity	80.81	83.87
			Specificity	75.23	71.43
			Efficiency	77.97	77.40
	MC	5	Accuracy	92.79	94.23
			Sensitivity	96.97	90.32
			Specificity	88.99	100.00
			Efficiency	92.89	95.04
	FD	5	Accuracy	98.56	100.00
			Sensitivity	99.04	100.00
			Specificity	98.08	100.00
			Efficiency	98.56	100.00
	SD	5	Accuracy	100.00	100.00
			Sensitivity	100.00	100.00
			Specificity	100.00	100.00
			Efficiency	100.00	100.00