Table 3. Analysis of variance (ANOVA) of mixture design and regression equations for bacterial change cycles under gastric pH and bile salt conditions.
| Bacterial change cycle | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Gastric pH | Bile salt | |||||||||
| Source | Sum of squares | Df | Mean square | F-value | p-value | Sum of squares | Df | Mean square | F-value | p-value |
| Model | 1.86 | 6 | 0.31 | 246.54 | <0.0001* | 2.36 | 5 | 0.47 | 60.03 | <0.0001* |
| Linear mixture | 0.27 | 2 | 0.14 | 109.09 | <0.0001* | 1.86 | 2 | 0.93 | 118.13 | <0.0001* |
| AB | 0.34 | 1 | 0.34 | 272.17 | <0.0001* | 0.01 | 1 | 0.01 | 0.90 | 0.36 |
| AC | 1.35 | 1 | 1.35 | 1075.74 | <0.0001* | 0.26 | 1 | 0.26 | 33.19 | 0.0001* |
| BC | 0.00 | 1 | 0.00 | 1.07 | 0.3245 | 0.21 | 1 | 0.21 | 26.60 | 0.0003* |
| ABC | 0.24 | 1 | 0.24 | 186.77 | <0.0001* | |||||
| Residual | 0.01 | 10 | 0.00 | 0.09 | 11 | 0.01 | ||||
| Lack of fit | 0.01 | 5.00 | 0.00 | 1.77 | 0.27 | 0.07 | 6.00 | 0.01 | 2.94 | 0.13 |
| Pure error | 0.00 | 5.00 | 0.00 | 0.02 | 5.00 | 0.00 | ||||
| Corr. total | 1.88 | 16.00 | 2.44 | 16.00 | ||||||
| R2 | 0.99 | 0.96 | ||||||||
| Final equation in terms of real components |
N/(log CFU/mL)=1.052A+0.692B+1.282C– –2.493AB–3.965AC+12.521ABC |
N/(log CFU/mL)=0.006A+0.504B+0.935C– –1.589AC+1.484BC |
||||||||
A=maltodextrin, B=gum arabic, C=whey; *significant at α=0.05