Table 5. Major volatile compounds of ayran samples.
| Sample | ||||||||
|---|---|---|---|---|---|---|---|---|
| Ctr | Ctr 2 | A5 | A5+MTG | A10 | A10+MTG | A15 | A15+MTG | |
|
γ(carbonyl compound)/(mg/L) t/day | ||||||||
| Acetaldehyde | ||||||||
| 1 | (14.4±1.2)a | 16.0±4.2 | 15.6±2.7 | 12.0±2.5 | 15.6±1.5 | 14.8±1.6 | 12.9±1.6 | 12.3±0.8 |
| 7 | (13.0±1.2)ab | 14.1±0.4 | 15.0±1.3 | 10.9±0.9 | 14.0±0.2 | 14.3±0.7 | 12.3±0.9 | 10.3±0.3 |
| 15 | (10.1±0.6)b | 12.7±1.2 | 11.1±1.1 | 13.1±0.8 | 12.3±0.9 | 15.5±4.2 | 12.8±1.7 | 10.9±1.4 |
| Diacetyl | ||||||||
| 1 | 9.6±1.3 | 15.9±1.5 | 13.1±0.4 | 10.4±1.0 | 15.34±1.8 | 13.7±1.1 | 16.8±0.5 | 11.9±0.6 |
| 7 | 11.8±1.5 | 19.5±0.7 | 17.5±3.0 | 17.1±1.8 | 15.9±3.5 | 14.1±4.9 | 11.6±1.4 | 11.4±1.2 |
| 15 | 11.4±1.5 | 9.9±1.8 | 14.3±1.4 | 12.8±2.4 | 10.1±0.4 | 14.4±1.6 | 11.7±1.8 | 13.1±1.1 |
| Acetoin | ||||||||
| 1 | (14.8±1.0)a | 19.8±1.5 | 22.4±2.1 | 21.7±1.6 | 25.2±1.4 | 23.1±3.5 | 17.9±2.8 | 17.4±2.2 |
| 7 | (21.7±1.8)b | 20.0±2.4 | 19.7±1.6 | 21.1±3.3 | 28.4±1.9 | 26.2±3.3 | 26.3±3.6 | 24.0±3.4 |
| 15 | (14.9±0.4)c | 13.0±0.9 | 15.0±0.6 | 11.6±1.8 | 14.7±1.5 | 13.6±1.2 | 10.5±0.6 | 10.3±0.7 |
| γ(compound other than carbonyl)/(mg/L) | ||||||||
| Hexenal | ||||||||
| 1 | (17.7±1.6)a | 20.9±0.8 | 20.4±2.0 | 22.0±1.6 | 25.2±1.4 | 23.6±1.7 | 14.0±3.1 | 19.6±4.7 |
| 7 | (14.9±1.1)b | 14.4±1.5 | 10.5±0.5 | 18.3±3.2 | 12.9±2.5 | 15.7±1.9 | 12.4±1.4 | 14.1±2.3 |
| 15 | (13.9±0.3)c | 10.9±0.8 | 12.2±0.4 | 13.1±0.5 | 12.6±0.6 | 8.0±0.6 | 9.3±1.5 | 12.6±0.5 |
| 2,3-Pentanedione | ||||||||
| 1 | (10.1±3.5)b | 11.8±1.9 | 10.8±0.3 | 11.8±1.34 | 15.6±4.1 | 14.0±1.6 | 13.2±2.6 | 12.8±2.0 |
| 7 | (15.0±3.5)a | 15.3±0.7 | 13.6±1.5 | 16.0±3.3 | 16.3±5.7 | 15.0±2.7 | 18.0±3.4 | 16.1±5.8 |
| 15 | (9.1±0.9)b | 6.2±1.0 | 10.0±0.5 | 11.6±1.9 | 13.1±0.3 | 9.4±0.6 | 10.80±0.04 | 11.8±1.6 |
| Benzaldehyde | ||||||||
| 1 | ndb | nd | nd | nd | 4.6±1.4 | 1.9±0.5 | nd | nd |
| 7 | ndb | nd | nd | 1.5±0.2 | nd | 3.1±0.5 | 2.9±0.4 | nd |
| 15 | (2.1±0.2)a | 4.1±0.5 | 2.0±0.2 | 2.1±0.3 | 4.6±1.3 | 2.8±1.9 | 4.3±1.6 | nd |
| 2-Octanone | ||||||||
| 1 | (1.1±0.3)b | 2.0±1.2 | 2.2±0.7 | 1.6±0.2 | 1.33±0.48 | 3.4±2.1 | 2.3±0.8 | 2.8±1.6 |
| 7 | (6.4±0.2)a | 5.3±0.9 | 6.0±1.1 | 5.92±0.04 | 6.5±0.2 | 9.4±1.2 | 6.6±2.0 | 6.2±0.9 |
| 15 | (1.70±0.03)b | 1.63±0.07 | 4.5±0.9 | 3.5±2.5 | 1.0±0.2 | 1.6±0.7 | 4.4±1.2 | 2.1±0.2 |
| 2-Nonanone | ||||||||
| 1 | ndb | 1.15±0.06 | nd | 1.3±0.3 | 0.2±0.2 | 1.5±0.1 | 0.99±0.02 | 1.1±0.1 |
| 7 | ndb | nd | nd | 1.5±0.3 | 2.6±0.8 | 3.3±1.0 | 1.4±0.4 | nd |
| D15 | (1.3±0.3)a | 1.2±0.2 | 3.0±0.2 | nd | 2.9±0.5 | 2.2±1.0 | 2.7±0.3 | nd |
| 2-Undecanone | ||||||||
| 1 | ndb | nd | nd | nd | nd | nd | nd | nd |
| 7 | ndb | nd | nd | nd | nd | nd | nd | nd |
| 15 | (1.10±0.09)a | 1.5±0.5 | 2.5±0.8 | 1.5±0.3 | 1.3±0.5 | 2.0±1.4 | 1.56±1.9 | 1.5±0.1 |
| Acetic acid | ||||||||
| 1 | (1.14±0.07)ab | 0.70±0.03 | 1.4±0.9 | 0.6±0.4 | 0.3±0.1 | 0.4±0.1 | 1.21±0.09 | 1.3±0.2 |
| 7 | (1.21±0.07)a | 0.9±0.2 | 0.7±0.2 | 0.8±0.5 | 2.6±2.1 | 2.6±1.0 | 1.22±0.62 | 0.7±0.2 |
| 15 | (1.4±0.1)b | 0.75±0.04 | 0.7±0.5 | 0.9±0.1 | 0.27±0.05 | 0.5±0.3 | 0.34±0.07 | 1.0±0.7 |
| Ethanol | ||||||||
| 1 | ndb | nd | nd | nd | nd | nd | nd | nd |
| 7 | ndb | nd | nd | nd | nd | nd | nd | nd |
| 15 | (0.4±0.2)a | nd | 0.23±0.01 | 0.98±0.08 | 0.79±0.09 | nd | nd | nd |
Mean value±S.E. (N=2) in the same column with different letters show significant differences during storage (p<0.05). Ctr 1 and 2=samples without RWP and MTG (1) and with MTG (2) as control; A5, A10 and A15=samples with 5, 10 and 15% RWP; A5+MTG, A10+MTG and A15+MTG=samples with 5, 10 and 15% RWP and 0.5 U/g MTG; RWP=reconstituted whey powder; MTG=microbial transglutaminase; nd=not detected