. 2024 Oct 31;13(21):3501. doi: 10.3390/foods13213501

Table 13.

Overview of NIR Results for Pome Fruits (Maloideae).

Sample	Investigated Parameter		Concentration Range	Chemometrics Data				Ref.
Sample	Investigated Parameter		Concentration Range	Pre-Processing, Regression		R²	Root Mean Square Error	Ref.
Apple	Soluble solid content—SSC, %		11.0–14.0	GA		0.911	0.251	[310]
			7.63–18.60	SNV, MSC, CARS-PLS		0.971	0.429	[313]
			8.00–13.60	SGS, 2nd der., CARS-SPA-PLS		0.850	0.443	[318]
			11.0–17.0	SGS, 1st der., SPA, MNLR		0.953	0.754	[323]
			7.8–24.1	SNV, LS-SVM		0.73	0.7	[328]
			9.13–15.66	CARS/PLS		0.9402	0.5079	[329]
	Complex model with pear		11.1–15.2	2nd der., PLS		0.88	0.43	[332]
	Complex model with pear and peach		10.20–15.60	SPA-MWPLS		0.96	0.46	[333]
	Complex model with pear and peach		10.20–15.60	MLR		0.96	0.46	[333]
	Titratable acidity—TA, %		0.9–28.4	SNV, LS-SVM		0.68	0.89	[328]
	Firmness, kg/cm²		1.5–12.7	SNV, LS-SVM		0.74	0.99
	Starch-Iodine Index		2–10	SNV, LS-SVM		0.73	0.84
	Visual ripeness index, VRPI		n.i.	LS-SVR		0.925	0.168	[324]
	RPI		n.i.	PLS		0.777	0.191
	IQI		n.i.	PLS		0.951	0.291
	Streif index		n.i.	PLS		0.768	0.082
	α-farnese, μmol/m²		15–1816	NCL, PLS		0.81–0.92	139	[327]
	CTols	CT258	14–502	1st der. BCAP, PLS		0.90; 0.94	59–60
	CT281		1–450	1st der. BCAP, PLS		0.91; 0.78	59–60
	Maturity estimation		SSC, TA, firmness, anthocyanin	SGS, SNV, MSC, SLS, 1st der. 2nd der. PLS, PCR, SMLR, GA-PLS		0.22–0.97	n.i.	[319]
	Internal flesh browning		93 good, 203 defect		PLS	0.83	0.63	[314]
	Sunscald		161 shaded and sun-exposed 100 mild sun damaged	MSC, 2nd der., PLS, iPLS-DA		0.454 0.594-	0.211 0.317	[317]
	Classification		Internal flesh browning		LDA	accuracy >95%		[314]
	Damage		Bruise, Mouldy core Sunburn Internal browning		PLS-DA, SPA-PLS, SELFS, iPLS-DA LDA	accuracy > 90%; 92% R²_cv = 0.59 accuracy 90%		[336]
			Maturation level—colour		ANN/SA	accuracy 100%		[331]
			Variety; Freshness; Variety, freshness		PCA, VIP, PLS-DA	misclassification 0%; 5.8%; 2.0–3.9%		[335]
			Bitter bit (BP)	269 BP 719 non BP	PLS-DA	accuracy 60–80%		[337]
			Origin	TCA, LS-SVM		accuracy 90.91%		[339]
			Fungal infection	SNV, CARS, SPA, KNN, LDA, LS/SVM, RF		accuracy 98.75%		[138]
Pear	Soluble solid content—SSC, %		8.6–13.8	PLS		0.912	0.662	[311]
			8.6–11.3	SGS, SNV, 1st der., var.sel. PLS		0.58	0.65	[312]
			10.8–14.6	SGS, PLS		0.92	0.41	[315]
			8.6–13.6-	aver. spectra, FWs PLS		0.8611	0.6314	[316]
			9.8–16.8	SGS, MSC, siPLS		0.9657	0.2265	[320]
			13.4–16.9	PCA, Si-GA-PLS,		0.9406	0.165	[321]
			7.20–19.5	SpectraNet–32		0.58	1.08	[322]
			8.2–16.5	SNV, 2nd der., SVM		0.71	0.7	[338]
			11.3–18.5	OSC-PLS		0.85	0.46	[374]
			11.3–18.5	OSC-MLR		0.86	0.46	[374]
	6 cultivars		10.2–25.0	Grad-CAM, SVR, CNN		n.i.	0.33–1.64	[326]
	Complex model with apple		9.2–13.8	2nd der., PLS		0.88	0.43	[332]
	Complex model with apple and peach		10.90–16.90	SPA-MWPLS, MLR		0.96 0.96	0.46 0.46	[333]
	Dry matter		11.4–21.8	SGS, SNV, 1st der., var.sel. PLS		0.65	1.06	[312]
	Firmness		4.2–11.3	PLS		0.854	1.232	[311]
			28.4–127.1	PCA, Si-GA-PLS,		0.9119	5.5003	[321]
			5.0–71.0	SNV, SVM		0.68	7.66	[338]
			15.00–35.86	PLS		0.58–0.845	2.65–3.98	[325]
			1.9–71.2	OSC-PLS		0.68	8.18	[374]
			1.9–71.2	OSC-MLR		0.56	9.28	[374]
	Maturity estimation		SSC, firmness, lignin cont.	SGS, SNV, MSC, OSC, 1st der., 2nd der., siPLS, UVE, MS-UVE-SPA, PLS, MLR, LSSVM, NIPALS		0.61–0.96	n.i.	[319]
	Classification		internal browning	PLS-DA		sensitivity 76%		[338]
			Insect-affect	SGS CBAM-CNN		accuracy 92.71%		[340]