Antioxidant activity and flavor compounds of hickory yogurt

Figures & data

Table 1. Analysis of main composition of CMY and HMY (g/100 g).

Composition	CMY	HMY
Ash	0.98 ± 0.02^a	0.64 ± 0.04^b
Total solids	18.75 ± 0.55^a	19.40 ± 1.50^a
Non-fat solids	16.09 ± 0.32^a	15.58 ± 1.25^a
Fat	2.66 ± 0.44^b	3.82 ± 0.50^a
Crude protein	2.94 ± 0.48^b	3.68 ± 0.85^a

Table 2. Analysis of amino acids composition of CMY and HMY (mg/g).

Amino acids	CMY	HMY
Aspartate (Asp)	1.606 ± 0.02^b	2.121 ± 0.02^a
Threonine (Thr)*	0.990 ± 0.01^a	1.164 ± 0.05^a
Serine (Ser)	1.038 ± 0.15^a	1.140 ± 0.03^a
Glutamate (Glu)	3.470 ± 0.20^b	4.546 ± 0.06^a
Glycine (Gly)	0.346 ± 0.01^a	0.428 ± 0.03^a
Alanine (Ala)	0.619 ± 0.01^a	0.593 ± 0.04^a
Cystein (Cys)	0.158 ± 0.01^a	0.200 ± 0.02^a
Valine (Val)*	1.169 ± 0.04^a	1.091 ± 0.01^a
Methionine (Met)*	0.798 ± 0.02^a	0.360 ± 0.02^a
Isoleucine (Ile)*	0.748 ± 0.03^b	1.209 ± 0.06^a
Leucine (Leu)*	1.807 ± 0.05^b	2.420 ± 0.20^a
Tyrosine (Tyr)	0.748 ± 0.03^b	1.135 ± 0.03^a
Phenylalanine (Phe)*	0.960 ± 0.02^a	1.203 ± 0.05^a
Lysine (Lys)*	1.445 ± 0.04^b	1.942 ± 0.04^a
Histidine (His)*	0.698 ± 0.02^b	0.637 ± 0.02^a
Arginine (Arg)*	0.314 ± 0.01^b	0.627 ± 0.01^a
Proline (Pro)	0.536 ± 0.01b	0.782 ± 0.02^a

Figure 1. Scores of sensory indicators for HMY and CMY.

Figure 2. IC₅₀ values of scavenging DPPH radical and inhibiting of lipid peroxidation of HMY and CMY.

Table 3. Flavor compounds of HMY and CMY.

		Relative peak area(%)
Compounds		HMY	CMY	RT(min)	Thresholds(ug/kg)
Aldehydes	Aldehyde	2.04 ± 0.01^a	1.78 ± 0.11^b	1.642	104
	Hexanal	0.77 ± 0.04^a	0.25 ± 0.08^b	7.683	4.5
	Benzaldehyde	0.46 ± 0.05^b	0.63 ± 0.08^a	16.033	2
	Furaldehyde	0.70 ± 0.08^a	0.65 ± 0.09^a	14.42	5.8
	Nonanal	0.57 ± 0.03^a	0.41 ± 0.08^b	18.725	1000
	Butyraldehyde	0.28 ± 0.01	—	2.78	280
Ketones	2,3-Diacetylmethane	6.24 ± 0.24^b	7.95 ± 0.28^a	4.79	1000
	2-Heptanone	0.13 ± 0.03^a	0.19 ± 0.05^a	11.61	141
	2-Nonanone	2.06 ± 0.52^a	1.64 ± 0.11^b	7.29	5
	2,3-Butanedione	7.27 ± 0.67^b	8.82 ± 0.48^a	2.390	3000
	1-Hydroxy-2-acetone	0.99 ± 0.06^a	1.35 ± 0.13^a	10.64	—
	3-Hydroxy-2-butanone	2.31 ± 0.45^b	8.47 ± 0.45^a	4.211	5000
	Acetone	0.82 ± 0.07^a	0.90 ± 0.09^a	1.848	500000
Acids	Hexanoic acid	3.44 ± 0.55^a	3.16 ± 0.23^b	23.41	3000
	Acetic acid	8.99 ± 0.87^b	10.20 ± 0.28^a	13.346	22000
	Butanoic acid	0.11 ± 0.02^b	2.79 ± 0.21^a	18.11	240
	Octanoic acid	0.98 ± 0.06a	1.40 ± 0.08^a	27.22	2701
	Heptanoic acid	0.24 ± 0.08^a	0.15 ± 0.04^b	25.11	3000
	Decanoic acid	1.75 ± 0.40^a	2.41 ± 0.46^a	30.9	10000
	Nonanoic acid	0.25 ± 0.01^a	0.07 ± 0.03^b	29.24	3000
	Benzoic acid	1.89 ± 0.05^b	2.84 ± 0.13^a	33.07	1000
Alcohols	Hexanol	0.62 ± 0.03^a	0.80 ± 0.13^a	5.14	250
	3-Pentanol	1.52 ± 0.25^b	2.52 ± 0.16^a	5.25	4000
	1,4-butanediol	1.55 ± 0.20^b	2.75 ± 0.54^a	12.71	—
Esters	Octyl formate	0.09 ± 0.01^b	0.22 ± 0.11^a	4.94	—
	propyl benzoate	1.74 ± 0.35^a	0.47 ± 0.05^b	3.43	—
	butyl acetate	0.33 ± 0.04^b	0.79 ± 0.11^a	9.41	1830
	ethyl acetate	0.07 ± 0.01	—	2.581	10
Else	2-pentyl-furan	0.5 ± 0.15	—	12.23	8000
	Methylbenzene	—	0.63 ± 0.10	5.00	200
	Paraxylene	0.09 ± 0.02^a	0.35 ± 0.12^a	11.31	—

RT: retention time.

The values were expressed by average ± standard deviation.

Different superscript letters in a row are significantly different, p < 0.05.