Table 2. Changes in volatile aroma compositions (%) of kefir during storage (1- 30 d)

	Control		MS		MS1		MS2		MS3

	1	30	1	30	1	30	1	30	1	30
Alcohols
Ethanol (CAS) Ethyl alcohol	0.29±0.09^bc	1.67±0.19^a	0.55±0.19^b	1.37±0.14^a	0.23±0.02^b	1.57±0.06^a	0.19±0.01^bc	1.47±0.07^a	0.18±0.02^c	1.68±0.03^a
1-Butanol, 3-methyl- (impure) (CAS)	0.13±0.01^cd	1.38±0.07^a	n.d.	0.58±0.05^b	0.14±0.00^cd	0.52±0.02^b	0.24±0.01^c	0.57±0.09^b	0.30±0.02^c	0.62±0.09^b
1-Pentanol (CAS) Amylol	n.d.	0.26±0.05^cd	0.42±0.04^abcd	1.03±0.07^a	0.35±0.00^bcd	0.50±0.50^abcd	0.36±0.00^bcd	0.92±0.17^ab	0.45±0.00^abcd	0.87±0.16^abc
Amyl methyl carbinol	0.26±0.03^c	1.40±0.20^a	0.18±0.01^c	1.12±0.02^ab	0.18±0.02^c	1.08±0.15^b	0.17±0.00^c	1.13±0.05^ab	0.22±0.01^c	1.17±.0.09^ab
2-Penten-1-ol, (Z)- (CAS)	n.d.	n.d.	0.12±0.00	0.09±0.00	0.43±0.33	0.17±0.06	0.12±002	0.22±0.02	0.14±0.00	0.21±0.03
Hexanol <n->	0.15±0.02^d	11.14±1.89^ab	3.59±0.35^c	12.09±0.79^a	3.45±0.30^c	9.60±0.64^ab	3.15±0.22^c	11.28±0.75^ab	4.11±0.01^c	9.52±0.13^b
Hexanol <2-ethyl->	0.19±0.02^b	0,28±0.01^a	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.	n.d.
1-Octen-3-ol (CAS) Oct-1-en-3-ol	0.15±0.01^g	0.68±0.07^f	2.52±0.13^cde	4.01±0.13^a	2.41±0.25^de	2.98±0.00^bc	2.04±0.18^e	3.27±0.23^b	2.65±0.06^cd	3.37±0.13^b
1-Heptanol (CAS) HEPTANOL	0.12±0.01^d	1.18±0.19^b	0.26±0.02^d	1.23±0.05^b	0.32±0.02^d	1.55±0.05^a	0.24±0.03^d	0.79±0.04^c	0.34±0.00^d	0.83±0.02^c
2-Hepten-1-ol, (E)-(CAS)	n.d.	n.d.	0.20±0.04^c	0.32±0.05^bc	0.23±0.01^c	0.37±0.05^b	0.18±0.01^c	0.68±0.01^a	0.23±0.02^c	0.71±0.09^a
Nonan-2-ol	n.d.	0.60±0.02^a	n.d.	0.68±0.01^a	n.d.	0.71±0.14^a	n.d.	0.64±0.04^a	n.d.	n.d.
2,3-Butanediol (CAS) Butane-2,3-diol	n.d.	0.22±0.02^bc	n.d.	0.51±0.11^bc	n.d.	0.52±0.11^bc	n.d.	0.79±0.16^b	n.d.	1.80±0.65^a
1-Octanol (CAS) Octilin	0.39±0.03^d	1.47±0.17^a	0.43±0.07^d	1.10±0.05^ab	0.49±0.15^cd	1.36±0.24^a	0.41±0.04^d	0.84±0.04^bc	0.39±0.01^d	0.73±0.00^bcd
2-Octen-1-ol, (E)- (CAS)	n.d.	n.d.	n.d.	0.34±0.02^b	0.19±0.00^c	0.35±0.05^b	0.17±0.03^c	0.68±0.04^a	0.08±0.00^d	0.63±0.02^a