Application of Pca and Slda Methods for the Classification and Differentiation of Cooked Pork From Chinese Indigenous Pig Breeds and A Hybrid Pig Breed

Figures & data

Table 1  Code and mean concentrations of cooked longissimus muscle from different breeds in headspace by SPME

		Mean concentration in headspace(ng/100 g)^A
Compound	Code	DLY	AQ	WP	DP	Sig^B
Octane	Octe	243.1 ± 4.3b	456.9 ± 6.9a	512.3 ± 3.9a	397.5 ± 1.7a	**
2,4-dimethyl-1-heptene	Dihe	69.7 ± 2.4bc	348.9 ± 11.0a	426.7 ± 4.1a	279.5 ± 10.1b	*
4-Methyloctane	Mete	34.5 ± 1.1a	197.5 ± 3.4b	294.8 ± 6.9b	247.6 ± 15.4a	*
Limonene	Lime	146.7 ± 5.4a	479.7 ± 3.2a	212.5 ± 7.1b	297.8 ± 3.4ab	*
Hexanal	Hexanal	1040.3 ± 11.0a	2041 ± 6.1c	3149.0 ± 35.8a	1866.0 ± 11.1b	*
Heptanal	Heptanal	331.5 ± 6.4a	624.6 ± 4.4b	560.8 ± 8.9a	717.4 ± 4.1a	**
Benzaldehyde	Benzaldehyde	1647.1 ± 10.4c	1277.6 ± 9.1a	2385.3 ± 13.6b	2060.4 ± 11.4a	**
Nonanal	Nonanal	1038.4 ± 5.5a	3771.3 ± 12.0b	2538.2 ± 22.6a	1646.1 ± 20.3b	*
1-Octanal	Octanal	201.8 ± 2.1b	1376.8 ± 7.5a	1807.0 ± 10.1a	2124.8 ± 13.2c	*
Decanal	Decanal	806.4 ± 2.1b	749.4 ± 6.5a	643.8 ± 8.2bc	912.4 ± 3.4a	**
(E)-2-Decenal	E2Decenal	318.7 ± 2.8bc	318.6 ± 2.8a	267.1 ± 7.0a	439.5 ± 5.3b	**
Dodecanal	Dodecanal	64.2 ± 1.3	232.9 ± 4.0	491.4 ± 4.9	365.9 ± 5.2	NS
Undecanal	Undecanal	103.4 ± 1.7c	358.3 ± 4.9bc	163.0 ± 4.5a	224.3 ± 3.9b	*
Hexadecanal	Hexadecanal	463.2 ± 3.8a	201.9 ± 1.3ab	351.2 ± 6.5b	179.3 ± 2.9bc	*
14-Octadecenal	Octadecenal14	12.2 ± 0.6	77.3 ± 1.0	112.9 ± 2.1	134.9 ± 3.3	NS
2-Undecenal	Undecenal2	202.1 ± 1.3a	289.6 ± 5.4bc	133.0 ± 1.9ab	234.3 ± 3.6b	**
(E)-2-Octenal	E2Octenal	216.6 ± 4.5a	356.1 ± 2.4b	501.0 ± 2.8b	533.1 ± 5.9a	**
2-Decene-1-ol	Decene1ol2	79.9 ± 1.1bc	59.2 ± 1.6a	113.5 ± 2.2b	217.5 ± 5.8a	*
trans-2-Undecene-1-ol	T2Undecene1ol	0.0 ± 0.0	251.1 ± 2.3	224.7 ± 2.5	134.7 ± 2.4	NS
(E)-2-Tetradecen-1-ol	E2Tetradecen1ol	293.1 ± 1.8a	2250.2 ± 18.1ab	1989.4 ± 6.0bc	1527.7 ± 7.4b	*
13-Heptadecyn-1-ol	Heptadecyn1ol13	24.1 ± 0.9	134.9 ± 2.4	234.0 ± 5.9	155.9 ± 2.1	NS
1-Octen-3-ol	Octen3ol1	582 ± 4.2a	820.2 ± 2.1bc	1354.1 ± 7.0ab	409.7 ± 5.2a	*
1-Octanol	Octanol	203.8 ± 1.9	369.5 ± 4.0	641.1 ± 6.2	159.0 ± 3.7	NS
n-Hexadcanoic acid	nHexadcanoicacid	598.3 ± 3.3	112.2 ± 2.7	165.0 ± 1.6	43.1 ± 1.0	NS
(E)-13-octadecenic acid	E13octadecenicacid	425.4 ± 2.5	42.8 ± 1.7	54.2 ± 1.1	22.2 ± 1.2	NS
2-Heptanone	Heptanone2	37.1 ± 0.6a	155.5 ± 1.6b	216.0 ± 3.4b	93.3 ± 1.4b	*
Heptanone	Heptanone	22.6 ± 0.7	368.6 ± 2.8	139.4 ± 3.3	253.6 ± 4.2	NS
2-Butanone	Butanone2	41.7 ± 0.8a	432.6 ± 2.1a	320.4 ± 5.1b	263.2 ± 4.3a	*
1-Hydroxy-2-propanone	Hydroxy2propanone1	21.8 ± 1.0	140 ± 1.0	344.1 ± 6.1	93.1 ± 1.7	NS
3-Hydroxy-2-butanone	Hydroxy2butanone3	0 ± 0.0	182.6 ± 92.1	127.0 ± 3.2	32.4 ± 1.3	NS
2-Pentylfuran	Pentylfuran2	2047.9 ± 21.7ab	3155.9 ± 17.9b	2703.1 ± 18.5a	3003.1 ± 20.7bc	**
2-Ethylfuran	Ethylfuran2	97.3 ± 1.5a	458 ± 2.6a	355.0 ± 5.4b	304.3 ± 3.0bc	*
2-hexylfuran	Hexylfuran2	101.5 ± 1.3	35.4 ± 2.2	53.4 ± 1.3	24.4 ± 0.9	NS

^AData are means of eight replicates; values in the same row with different letters were significantly different (P < 0.05 or P < 0.01). DLY: Yorkshire×Large White×Duroc; AQ: Anqingliubai; WP: Wannanhua Pig; DP: Dingyuan Pig.

^BProbability that there is a difference between samples; NS: not significantly different between means (P > 0.05).

*Significant at the 5% level.

**Significant at the 1% level.

***Significant at the 0.1% level.

Figure 1  PC1 vs. PC2 scatter plot of the main sources of variability between the pork samples: (a) distinction between the samples (scores) and (b) relation between the 13 aldehydes (loadings).

Table 2  Prediction capacity of pork samples discriminant model according to pork variety

Classification results
		Predicted group membership
Original	SS	1.00	2.00	3.00	4.00	Total
Count	1.00	8	0	0	0	8
	2.00	0	8	0	0	8
	3.00	0	0	8	0	8
	4.00	0	0	0	8	8
%	1.00	100.0	.0	.0	.0	100.0
	2.00	.0	100.0	.0	.0	100.0
	3.00	.0	.0	100.0	.0	100.0
	4.00	.0	.0	.0	100.0	100.0

1: DLY pork samples; 2: AQ pork samples; 3: WP pork samples; 4: DP pork samples. 100.0% of original grouped cases correctly classified.

Figure 2  PC1 vs. PC2 scatter plot of the main sources of variability between the pork samples: (a) distinction between the samples (scores) and (b) relation between the 12 acids, alcohols, and alkanes (loadings).

Figure 3  PC1 vs. PC2 scatter plot of the main sources of variability between the pork samples: (a) distinction between the samples (scores) and (b) relation between the eight Ketones and furans (loadings).