Table 2.

Volatile compounds detected by PTR-ToF-MS in blueberry fruits at different ripening stages.

m/z	Formula	SOTAa	Tentative identification	Minb	Maxb	Meanb
28.008		1	n.i.	0.6	0.7	0.6
29.040	C2${\text{H}}_5^{+}$	8	Ethanol fragment	1.9	64.8	2.4
30.995		1	n.i.	1.0	1.2	1.0
31.019	CH3O+	8	Formaldehyde	2.8	14.2	5.2
33.994	O[18]O+	1	n.i.	4.7	5.1	4.9
34.037	[13]CH4OH+	8	Methanol	3.4	92.7	17.8
39.023	C3${\text{H}}_3^{+}$	3	Common fragment	5.2	29.8	12.2
41.039	C3${\text{H}}_5^{+}$	3	Common fragment	12.3	56.3	21.9
43.018	C2H3O+	3	Common fragment	26.1	129.8	50.3
43.054	C3${\text{H}}_7^{+}$	3	Common fragment	3.3	23.0	8.8
45.033	C2H4OH+	8	Acetaldehyde	59.8	1358.0	176.1
45.992	${\text{NO}}_2^{+}$	1	n.i.	1.2	1.6	1.4
47.013	CH3O${\text{O}}_2^{+}$	5	Formic acid	7.2	18.3	10.2
47.024		1	n.i.	4.4	5.2	4.7
47.049	C2H6OH+	8	Ethanol	2.3	295.5	4.5
49.012	CH4SH+	2	Methanethiol	0.2	0.8	0.4
51.023		6	n.i.	0.2	0.9	0.4
51.043	CH3OH*H3O+	8	Methanol cluster	4.7	132.4	25.0
53.039	C4${\text{H}}_5^{+}$	3	n.i.	1.5	8.9	3.9
55.018		2	n.i.	0.2	1.8	0.7
55.054	C4${\text{H}}_7^{+}$	2	Common fragment	21.4	193.8	81.5
55.934		1	n.i.	1.1	1.2	1.2
57.033	C3H4OH+	5	Common fragment	48.1	779.2	231.2
57.070	C4${\text{H}}_9^{+}$	3	1-Octanol*, high alcohol fragment	0.1	5.1	3.6
59.049	C3H6OH+	7	Acetone	26.6	880.1	37.6
61.028	C2H4O2H+	6	Acetic acid, common ester fragment	10.2	52.5	19.0
63.026	C2H6SH+	4	Dimethyl sulfide, Ethanethiol	0.8	42.7	1.6
63.043	C2H4O*H3O+	8	Ethanol cluster	0.2	3.5	0.4
65.022		4	n.i.	0.2	2.1	0.3
65.039	C5${\text{H}}_5^{+}$	3	n.i.	0.1	0.4	0.1
67.054	C5${\text{H}}_7^{+}$	3	n.i.	0.9	4.2	1.8
69.034	C4H4OH+	2	Furan	0.3	1.1	0.6
69.070	C5${\text{H}}_9^{+}$	3	Aldehyde fragment	3.8	22.4	8.7
70.039		3	n.i.	0.0	0.3	0.1
71.049	C4H6OH+	2	Butenal	1.6	6.6	3.6
71.086	C5${\text{H}}_{11}^{+}$	4	3-Methyl-1-butanol*, 2-Methyl-1-butanol*, Pentanol*	1.1	10.8	2.7
73.028	C3H4O2H+	1	n.i.	0.8	1.0	0.9
73.048		1	n.i.	0.7	1.2	1.0
73.065	C4H8OH+	2	Butanale, Isobutyraldehyde	2.5	7.2	4.3
75.027	C3H6SH+	1	Allyl mercaptan, 3-mercaptopropanol	1.1	1.7	1.4
75.044	C3H6O2H+	8	Methyl acetate*	0.9	45.4	1.2
78.047	C6${\text{H}}_6^{+}$	1	n.i.	2.4	2.6	2.5
79.055	C6${\text{H}}_7^{+}$	3	Benzene	4.0	11.6	7.9
80.060	C5[13]${\text{CH}}_7^{+}$	3	n.i.	0.4	2.0	0.8
81.070	C6${\text{H}}_9^{+}$	4	Fragment of aldehydes (hexenals); fragment of terpenes (linalool)	19.1	1497.7	283.8
83.049	C5H6OH+	2	Methylfuran	0.5	2.9	1.3
83.086	C6${\text{H}}_{11}^{+}$	5	(E)-3-hexen-1-ol*, (Z)-3-hexen-1-ol*, (Z)-2-hexen-1-ol*, Hexanal*,2-Hexanone	14.3	123.0	49.9
85.065	C5H8OH+	4	3-Penten-2-one	2.2	17.5	6.7
85.100	C6${\text{H}}_{13}^{+}$	6	Hexanol*	0.3	1.2	0.4
87.044	C4H6O2H+	3	Butyrolactone*	0.8	4.5	1.1
87.080	C5H10OH+	3	2-Methyl butanal*, 3-Methyl butanal*	1.0	4.6	1.8
89.060	C4H8O2H+	8	Ethyl acetate*	0.8	11.2	1.2
90.949		1	n.i.	1.8	1.9	1.9
91.057	C7${\text{H}}_7^{+}$	1	Benzyl fragment*	0.9	1.5	1.1
93.037	C3H8OSH+	1	2-(Methylthio)ethanol	1.4	1.7	1.5
93.070	C7${\text{H}}_9^{+}$	6	Monoterpene fragment	0.5	2.1	0.8
94.041		1	n.i.	0.4	0.5	0.4
95.022		1	n.i.	0.4	0.6	0.5
95.049	C6H6OH+	1	Phenol	1.6	2.2	1.9
95.086	C7${\text{H}}_{11}^{+}$	1	(E)-2-heptenal*, Monoterpene fragment	1.1	4.2	2.2
97.065	C6H8OH+	4	(E,Z)-2,4-hexadienal*, (E,E)-2,4-hexadienal*	0.4	3.1	1.2
97.102	C7${\text{H}}_{13}^{+}$	3	Heptanal*, fragment	0.5	2.5	0.6
99.080	C6H10OH+	3	(Z)-3-hexenal*, (lZ)-2-hexenal*, (E)-2-hexenal*	17.9	433.9	145.8
101.064	C5H8O2H+	3	2,3-Pentanedione	0.3	0.8	0.4
101.095	C6H12OH+	5	Hexanal*	2.1	16.9	6.3
103.076	C5H10O2H+	8	Ethyl propanoate*	0.5	8.0	0.6
105.071	C8${\text{H}}_9^{+}$	6	Phenethyl alcohol*, Styrene	0.1	0.4	0.2
105.938		1	n.i.	0.2	0.2	0.2
107.050	C7H6OH+	2	Benzaldehyde*	0.2	0.5	0.3
107.086	C8H10H+	1	Ethyl benzene*, p-Xylene*, m-Xylene*	3.7	15.6	9.6
107.953		1	n.i.	0.3	0.3	0.3
108.957		1	n.i.	0.7	0.8	0.7
109.102	C8${\text{H}}_{13}^{+}$	5	n.i.	2.1	7.7	3.3
111.081	C7H10OH+	3	(E,E)-2,4-heptadienal*	0.3	1.1	0.6
111.118	C8${\text{H}}_{15}^{+}$	1	(E)-2-Octenal*, Octanal*,1-Octen-3-ol	0.3	0.5	0.4
113.027		2	n.i.	0.1	0.2	0.2
113.060	C6H8O2H+	4	Sorbic acid	0.2	2.0	0.4
113.097	C7H12OH+	1	(E)-2-heptenal*	0.3	1.2	0.6
115.077	C6H10O2H+	2	Ethyl (2E)-2-butenoate*	0.2	0.6	0.3
115.113	C7H14OH+	4	2-Heptanone*, Heptanal	0.2	24.2	1.3
117.092	C6H12O2H+	8	Ethyl isobutanoate*, Methyl-2-methyl butanoate*, Methyl isovalerate*, Ethyl butyrate*, Hexanoic acid*	0.9	17.6	1.2
119.088	C9${\text{H}}_{11}^{+}$	1	3-Phenylpropanol	0.5	0.6	0.5
121.066	C8H8OH+	2	Acetophenone*, Phenylacetaldehyde	0.6	1.6	0.9
121.103	C9${\text{H}}_{13}^{+}$	1	1,3,5-Trimethylbenzene	0.2	0.3	0.3
123.118	C9${\text{H}}_{15}^{+}$	1	2-Nonenal*, (E)-2-nonenal*	0.3	0.4	0.3
125.097	C8H12OH+	3	6-Methyl-3,5-heptadien-2-one	0.2	0.6	0.3
126.903		1	n.i.	0.3	0.3	0.3
127.113	C8H14OH+	5	1-Octen-3-one*, 6-Methyl-5-hepten-2-one*, (E)-2-octenal*, β-Myrcene*, Limonene*, (E)-β-Ocimene*, α-Terpinolene*	0.8	3.0	1.4
129.128	C8H16OH+	1	2-Octanone*, Octanal*, 1-Octen-3-ol	0.2	0.5	0.3
131.107	C7H14O2H+	8	Ethyl-2-methyl butanoate*, Ethyl isovalerate*	0.2	6.0	0.3
133.102	C10${\text{H}}_{13}^{+}$	1	Thymol	0.1	0.4	0.2
135.118	C10${\text{H}}_{15}^{+}$	7	HO-trienol*	0.3	3.6	0.7
137.134	C10${\text{H}}_{17}^{+}$	3	1,8-cineole*, Linalool*, 4-Terpineol*, α-Terpineol*, Nerol*, Geraniol*	1.6	13.2	5.8
139.076	C8H10O2H+	1	5,5-Dimethyl-2-cyclohexen-1,4-dione	0.1	0.3	0.2
139.115	C9H14OH+	2	n.i.	0.2	0.4	0.3
141.129	C9H16OH+	1	2-Nonenal*, (E)-2-nonenal*, Ethyl sorbate	0.2	0.3	0.3
143.108	C8H14O2H+	3	(Z)-3-hexenyl acetate*, 2-Hexenyl acetate*	0.2	0.6	0.3
143.145	C9H18OH+	3	2-Nonanone*, Nonanal	0.1	0.8	0.4
144.914		1	n.i.	0.1	0.2	0.2
145.124	C8H16O2H+	1	Ethyl hexanoate*, Hexyl acetate*, Octanoic acid*	0.5	0.8	0.7
153.129	C10H16OH+	7	HO-trienol*, 2,4-Decadienal	0.3	6.0	0.9
155.144	C10H18OH+	5	1,8-Cineole*, Linalool*, 4-Terpineol*, α Terpineol*, Nerol*, Geraniol*	0.2	0.5	0.4
159.140	C9H18O2H+	1	Nonanoic acid*	0.7	1.6	1.2
173.156	C10H20O2H+	1	Decanoic acid*	0.4	0.8	0.7
177.166	C13${\text{H}}_{21}^{+}$	1	Geranyl acetone*	0.2	0.4	0.3

^aSOTA (self-organizing tree algorithm) clusters based on Figure 3.

^bppb_v.

^*Compound detected also by SPME-GC-MS analysis.