Pattern recognition analysis on nutritional profile and chemical composition of edible bird’s nest for its origin and authentication

Figures & data

Table 1. Information of edible bird’s nest samples.

Sample	Production origin^a	Species origin	Geographical origin^a	Location
EBN 1	House	A. fuciphagus	Peninsular Malaysia	Segamat, Johor
EBN 2	House	A. fuciphagus	Peninsular Malaysia	Kapar, Selangor
EBN 3	House	A. fuciphagus	Peninsular Malaysia	Nibong Tebal, Penang
EBN 4	House	A. fuciphagus	Peninsular Malaysia	Klang, Selangor
EBN 5	House	A. fuciphagus	East Malaysia	Sarikei, Sarawak
EBN 6	Cave	A. fuciphagus	East Malaysia	Gomantong Cave, Sabah
EBN 7	Cave	A. fuciphagus	East Malaysia	Baram, Sarawak
EBN 8	Cave	A. maximus	East Malaysia	Gomantong Cave, Sabah
EBN 9	Cave	A. maximus	East Malaysia	Niah Cave, Sarawak
EBN 10	Cave	A. maximus	East Malaysia	Niah Cave, Sarawak
EBN 11	Cave	A. maximus	East Malaysia	Subis Cave, Sarawak
EBN 12	NA	A. fuciphagus	NA	Local market
EBN 13	NA	A. fuciphagus	NA	Local market

A. fuciphagus, Aerodramus fuciphagus; A. maximus, Aerodramus maximus.

^aNA indicates not known.

Table 2. Physicochemical properties, proximate composition, antioxidant activities, elemental content, amino acid profile, nitrite, nitrate and sialic acid contents in EBN samples with respect to production, species and geographical origins.

	Production origin		Species origin		Geographical origin
	House (n = 10)	Cave (n = 12)	A. fuciphagus (n = 18)	A. maximus (n = 8)	Peninsular Malaysia (n = 8)	East Malaysia (n = 14)
Physicochemical
Water activity	0.67 ± 0.04	0.68 ± 0.14	0.67 ± 0.10	0.66 ± 0.12	0.67 ± 0.05	0.68 ± 0.13
Colour L*	50.43 ± 1.84	42.19 ± 7.45	52.72 ± 3.87	37.21 ± 0.91	50.06 ± 1.71	43.58 ± 7.73
Colour a*	2.08 ± 0.22	4.09 ± 1.73	3.18 ± 1.80	2.97 ± 0.45	2.01 ± 0.18	3.84 ± 1.71
Colour b*	15.83 ± 1.27	17.30 ± 5.47	18.42 ± 3.76	13.63 ± 0.57	15.91 ± 1.39	17.04 ± 5.08
Hue	82.50 ± 0.65	77.05 ± 1.62	80.75 ± 2.97	77.76 ± 1.33	82.79 ± 0.25	77.67 ± 2.16
Chroma	15.97 ± 1.28	17.79 ± 5.72	18.73 ± 4.03	13.95 ± 0.65	16.04 ± 1.40	17.49 ± 5.32
Proximate (g kg^−1)
Moisture	182 ± 15	186 ± 66	183 ± 48	169 ± 48	184 ± 17	185 ± 61
Protein	566 ± 26	574 ± 48	583 ± 41	566 ± 42	568 ± 29	572 ± 44
Carbohydrate	222 ± 23	191 ± 32	208 ± 32	206 ± 29	220 ± 26	197 ± 33
Ash	56.18 ± 0.89	79.89 ± 20.80	54.47 ± 11.88	85.38 ± 23.94	56.02 ± 0.93	76.60 ± 20.88
Fat	1.38 ± 1.63	0.38 ± 0.55	1.01 ± 1.33	0.19 ± 0.20	1.57 ± 1.79	0.40 ± 0.51
Antioxidant (g kg^−1)
TPC	14.61 ± 0.48	2.73 ± 1.88	12.25 ± 4.96	2.41 ± 1.97
DPPH	3.18 ± 0.33	1.32 ± 0.33	2.52 ± 0.98	1.49 ± 0.23	14.45 ± 0.37	4.52 ± 4.87
FRAP	2.09 ± 0.43	0.94 ± 0.48	1.64 ± 0.67	1.06 ± 0.55	3.12 ± 0.33	1.62 ± 0.83
					2.13 ± 0.48	1.08 ± 0.58
Elemental (mg kg^−1)
Sodium	14634 ± 3352	14353 ± 4164	15161 ± 3985	13743 ± 2399	14318 ± 3684	14574 ± 3892
Calcium	5584 ± 393	16541 ± 10387	7967 ± 4996	16908 ± 12410	5693 ± 361	14913 ± 10412
Magnesium	1514 ± 98	2377 ± 449	1745 ± 508	2418 ± 482	1545 ± 83	2236 ± 547
Potassium	681 ± 411	678 ± 338	635 ± 391	557 ± 350	677 ± 465	685 ± 311
Iron	21.58 ± 10.56	23.01 ± 9.05	20.88 ± 9.40	22.25 ± 9.40	18.67 ± 9.74	24.47 ± 9.12
Copper	5.22 ± 0.45	5.13 ± 0.72	5.13 ± 0.57	5.21 ± 0.61	5.33 ± 0.44	5.08 ± 0.67
Zinc	3.53 ± 0.68	5.84 ± 3.04	3.79 ± 1.29	6.75 ± 3.26	3.73 ± 0.61	5.39 ± 3.01
Phosphorus	0.23 ± 0.01	0.26 ± 0.04	0.24 ± 0.04	0.27 ± 0.04	0.23 ± 0.03	0.25 ± 0.04
Lead	0.164 ± 0.089	0.190 ± 0.086	0.152 ± 0.084	0.197 ± 0.089	0.184 ± 0.089	0.174 ± 0.088
Mercury	0.081 ± 0.007	0.073 ± 0.005	0.097 ± 0.034	0.071 ± 0.006	0.083 ± 0.006	0.073 ± 0.005
Arsenic	0.069 ± 0.014	0.067 ± 0.007	0.061 ± 0.016	0.068 ± 0.008	0.075 ± 0.007	0.065 ± 0.010
Cadmium	0.003 ± 0.001	0.005 ± 0.002	0.005 ± 0.003	0.004 ± 0.001	0.003 ± 0.001	0.005 ± 0.002
Amino acid (g kg^−1)
Lysine	41.58 ± 6.89	33.99 ± 10.83	40.37 ± 8.36	33.00 ± 10.44	40.16 ± 7.04	35.88 ± 11.07
Threonine	40.68 ± 6.08	36.31 ± 11.86	42.77 ± 7.86	31.47 ± 7.32	41.05 ± 6.84	36.37 ± 10.96
Leucine	39.46 ± 4.78	37.99 ± 4.07	41.01 ± 5.11	36.34 ± 2.35	40.03 ± 5.24	37.88 ± 3.75
Phenylalanine	35.91 ± 8.02	33.23 ± 9.11	37.00 ± 8.13	29.69 ± 4.27	36.65 ± 8.92	33.19 ± 8.38
Valine	35.78 ± 1.69	32.46 ± 4.25	36.75 ± 1.94	30.33 ± 3.55	35.91 ± 1.88	32.83 ± 4.03
Isoleucine	22.40 ± 2.68	18.64 ± 4.60	21.66 ± 3.27	18.08 ± 5.18	22.12 ± 2.96	19.34 ± 4.59
Histidine	20.31 ± 10.70	19.15 ± 13.02	22.55 ± 12.13	16.90 ± 8.70	23.30 ± 9.80	17.61 ± 12.61
Methionine	2.79 ± 0.92	2.03 ± 1.18	2.63 ± 0.92	1.53 ± 0.98	2.77 ± 1.04	2.15 ± 1.13
Serine	55.09 ± 6.99	53.14 ± 12.99	57.82 ± 8.60	48.70 ± 10.95	55.81 ± 7.73	53.00 ± 11.95
Aspartic acid	46.75 ± 6.46	40.34 ± 11.32	48.03 ± 9.41	38.91 ± 10.49	46.37 ± 7.27	41.47 ± 10.81
Glutamic acid	43.22 ± 3.96	36.61 ± 7.68	43.64 ± 6.58	35.95 ± 8.01	42.79 ± 4.37	37.81 ± 7.69
Proline	37.78 ± 5.79	38.09 ± 4.62	40.34 ± 6.49	36.16 ± 3.32	38.43 ± 6.36	37.68 ± 4.40
Arginine	37.11 ± 5.18	37.17 ± 8.34	38.94 ± 6.56	34.69 ± 5.48	37.51 ± 5.79	36.93 ± 7.70
Tyrosine	33.39 ± 12.86	26.23 ± 18.45	35.10 ± 12.69	19.52 ± 15.12	34.72 ± 14.23	26.49 ± 16.99
Glycine	27.60 ± 3.19	23.30 ± 8.43	26.44 ± 8.91	19.17 ± 5.87	27.28 ± 3.54	24.09 ± 8.02
Alanine	15.12 ± 1.76	15.66 ± 3.13	15.70 ± 2.53	16.30 ± 3.74	15.25 ± 1.97	15.51 ± 2.91
Nitrite (mg kg^−1)	31.63 ± 54.99	702 ± 473	114 ± 266	844 ± 427	37.07 ± 60.98	603 ± 502
Nitrate (mg kg^−1)	133.43 ± 79.22	31992 ± 29569	4966 ± 9395	36999 ± 35866	138.59 ± 88.97	27438 ± 29561
Sialic acid (g kg^−1)	116.53 ± 3.99	79.88 ± 24.07	112.74 ± 9.02	65.00 ± 10.25	116.50 ± 4.44	85.13 ± 25.86

A. fuciphagus, Aerodramus fuciphagus; A. maximus, Aerodramus maximus.

Values are given as mean ± standard deviation.

Table 3. Ranking of variables based on F-ratio value in differentiating EBN following (a) production origin, (b) species origin and (c) geographical origin.

(a)		(b)		(c)
Variable	F-ratio value	Variable	F-ratio value	Variable	F-ratio value
TPC	374.92	Sialic acid	143.00	Hue	43.83
DPPH	175.33	Colour L*	123.04	TPC	32.43
Hue	99.24	Valine	36.06	DPPH	23.11
Magnesium	35.26	TPC	28.87	Mercury	20.37
FRAP	34.25	Nitrite	28.52	FRAP	18.71
Sialic acid	22.50	Ash	19.82	Magnesium	12.37
Nitrite	19.73	Nitrate	12.98	Sialic acid	11.34
Colour a*	13.27	Colour b*	12.59	Nitrite	9.87
Ash	12.87	Threonine	11.90	Colour a*	8.94
Colour L*	11.54	Zinc	11.31	Ash	7.59
Nitrate	11.51	Chroma	10.85	Arsenic	7.43
Calcium	11.02	Magnesium	9.99	Nitrate	6.68
Mercury	9.20	DPPH	8.42	Calcium	6.14
Carbohydrate	6.52	Methionine	7.68	Fat	5.39
Cadmium	6.13	Tyrosine	7.44	Colour L*	5.37
Glutamic acid	6.03	Hue	7.36
Zinc	5.49	Calcium	7.07
Valine	5.36	Glutamic acid	6.63
Isoleucine	5.18	Leucine	6.02
		Phenylalanine	5.69
		Serine	5.27
		Aspartic acid	4.86
		FRAP	4.63
		Isoleucine	4.59
		Mercury	4.49
		Glycine	4.42

Figure 1. PCA plots of EBN classification based on production origin. (a) Score plot of house (H) and cave (C). (b) Loading plot of 15 compositional variables, (1) color L*; (2) hue; (3) carbohydrate; (4) ash; (5) TPC; (6) mercury; (7) cadmium; (8) calcium; (9) magnesium; (10) zinc; (11) valine; (12) isoleucine; (13) glutamic acid; (14) nitrite; (15) sialic acid. The grey circle indicates unit circle.

Figure 2. HCA dendrogram of EBN clustering based on production origin. The observations, H, house; C, cave; 1–11, EBN samples; a/b, replicates.

Table 4. Classification and prediction abilities of the LDA models developed for different origin classifications.

Classes of origin	Classification ability		Prediction ability
	AccuracyΦ		Sensitivity^†	Specificity^‡	Accuracy^Φ
Production origin	100% (22/22)		100% (10/10)	100% (12/12)	100% (22/22)
Species origin	100% (26/26)		89% (16/18)	100% (8/8)	92% (24/26)
Geographical origin	100% (22/22)		100% (8/8)	100% (14/14)	100% (22/22)

^† Sensitivity (True positive rate) = TP/(TP + FN)

^‡ Specificity (True negative rate) = TN/(TN + FP)

^Φ Accuracy = Number of correct observations/Total number of observations

* TP, true positive; TN, true negative; FN, false negative; FP, false positive of observations

Figure 3. PCA plots of EBN classification based on species origin. (a) Score plot of Aerodramus fuciphagus (AF) and Aerodramus maximus (AM). (b) Loading plot of 21 compositional variables, (1) color L*; (2) hue; (3) ash; (4) TPC; (5) mercury; (6) calcium; (7) magnesium; (8) zinc; (9) threonine; (10) leucine; (11) phenylalanine; (12) valine; (13) isoleucine; (14) methionine; (15) serine; (16) aspartic acid; (17) glutamic acid; (18) tyrosine; (19) glycine; (20) nitrite; (21) sialic acid. The gray circle indicates unit circle.

Figure 4. HCA dendrogram of EBN clustering based on species origin. The observations, AF, Aerodramus fuciphagus; AM, Aerodramus maximus; 1–13, EBN samples; a/b, replicates.

Figure 5. PCA plots of EBN classification based on geographical origin. (a) Score plot of Peninsular Malaysia (P) and East Malaysia (E). (b) Loading plot of 11 compositional variables, (1) color L*; (2) hue; (3) ash; (4) fat; (5) TPC; (6) mercury; (7) arsenic; (8) calcium; (9) magnesium; (10) nitrite; (11) sialic acid. The gray circle indicates unit circle.

Figure 6. HCA dendrogram of EBN clustering based on geographical origin. The observations, P, Peninsular Malaysia; E, East Malaysia; 1–11, EBN samples; a/b, replicates.