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
Organic acids
Acetic acid 4.75±0.00de 5.35±0.20d 5.91±0.42d 10.40±0.06b 3.91±0.62ef 8.71±0.65c 5.51±0.44d 9.01±0.24c 3.43±0.07f 13.58±0.40a
Butanoic acid (CAS) n-Butyric acid 0.80±0.10b 1.43±0.19a 0.60±0.08b 1.39±0.05a 0.48±0.01b 0.84±0.15b 0.58±0.01b 1.23±0.04a 0.62±0.04b 1.39±0.18a
Hexanoic acid (CAS) n-Hexanoic acid 8.44±0.47abcd 9.59±0.21a 7.32±0.54cde 9.10±0.25ab 6.80±0.10de 8.97±1.28abc 7.42±0.38bcde 8.51±0.12abcd 6.47±0.23e 8.01±0.31abcde
Propanoic acid n.d. n.d. 0.14±0.01 0.32±0.02 0.29±0.00 n.d. 0.28±0.01 0.38±0.14 0.79±0.49 0.28±0.03
Octanoic acid (CAS) Caprylic acid 15.45±0.69a 12.11±0.61b 9.55±0.30c 11.68±0.81b 10.56±0.61bc 9.24±0.12c 11.31±0.800b 9.46±0.04c 9.12±0.33c 9.06±0.15c
Nonanoic acid (CAS) 0.26±0.01b 0.17±0.06b 1.43±0.24a n.d. 0.23±0.02b n.d. 0.31±0.09b n.d. 1.63±0.13a n.d.
Capric acid 13.35±0.75a 11.29±0.12b 7.24±0.19e 8.52±0.50cde 9.68±0.06c 7.78±0.46de 8.21±0.53cd 8.91±0.17cd 8.19±0.12de 8.52±0.04d
9 DECENOIC ACID 1.24±0.02a 0.77±0.11b 0.62±0.07b 0.65±0.02b 0.74±0.01b 0.54±0.01b 0.74±0.19b 0.61±0.05b 0.59±0.09b 0.67±0.07b
Benzoic acid (CAS) Retardex 9.13±1.07a 2.08±0.01d 7.12±0.10b 4.79±0.29c 6.47±0.24b 6.11±0.07bc 7.05±0.41b 5.86±0.46bc 6.26±0.18bc 6.47±0.50b
Dodecanoic acid (CAS) Lauric acid 15.20±1.70a 4.23±0.42b 4.80±0.24b 5.37±0.14b 4.95±0.21b 4.41±0.54b 5.56±0.20b 5.19±0.07b 6.08±0.03b 5.36±0.52b
Tetradecanoic acid (CAS) Myristic acid n.d. 16.92±0.93a 14.69±0.94ab 11.48±0.11c 16.90±0.86a 16.58±1.58a 8.48±0.07d 12.60±0.71bc 10.53±1.03cd 11.65±0.15c
Total (%) 68.62±0.01a 63.94±0.04c 59.42±0.05g 63.70±0.05d 61.01±0.02f 63.60±0.10d 55.45±0.05h 62.12±0.06e 53.71±0.06i 65.31±0.09b
Miscellaneous
Carbon dioxide (CAS) 1.27±0.01d 1.83±0.02cd 2.05±0.05bc 2.11±0.12abc 2.50±0.18abc 2.80±0.20a 1.85±0.02cd 2.67±0.55ab 2.17±0.02abc 2.30±0.16abc
Benzene, 1,3-dichloro- 0.25±0.04a 0.14±0.00b n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d.
Butanoic acid, propyl ester (CAS) n.d. n.d. n.d. n.d. n.d. 0.42±0.05a n.d. 0.36±0.01ab n.d. 0.32±0.06b
Others 1.07±0.00 5.46±0.02 4.20±0.07 2.34±0.04 4.94±0.00 3,60±0.02 6.62±0.05 3.45±0.01 4.16±0.09 1.33±0.04
Total (%) 1,55±0.02 1.85±0.02 2.03±0.02 2.13±0.02 2.57±0.07 3.25±0.03 2.61±0.03 3.14±0.11 2.33±0.14 2.58±2.58