Table 2.
Stratification meta-analysis according to the type of stevia extract for the TPC assay.
| Assay | Type of Extract | Effect Size | CI 95% | Number of Studies |
|---|---|---|---|---|
| TPC (mg GAE/g) |
Aqueous | 63.73 | 58.37, 69.09 | 28 |
| Hydroalcoholic | 64.77 | 56.39, 73.15 | 27 | |
| Organic | 33.39 | 28.75, 38.02 | 26 | |
| Phenols | 187.66 | 187.45, 187.87 | 1 | |
| Flavonoids | 8.99 | 5.02, 12.95 | 3 | |
| Hydroalcoholic (methanol/ethanol) | Methanol | 47.93 | 24.72, 71.13 | 6 |
| Ethanol | 71.26 | 58.16, 84.37 | 20 | |
| Hydroalcoholic (alcohol %) |
Methanol 80% | 51.41 | 24.92, 77.91 | 5 |
| Methanol 85% | 30.50 | 29.52, 31.48 | 1 | |
| Ethanol 12% | 78.00 | 76.29, 79.70 | 1 | |
| Ethanol 50% | 113.60 | 79.20, 148.01 | 7 | |
| Ethanol 60% | 43.39 | 26.55, 60.23 | 4 | |
| Ethanol 70% | 58.20 | 30.50, 85.90 | 6 | |
| Ethanol 75% | 20.00 | 17.27, 22.72 | 1 | |
| Ethanol 80% | 12.80 | 12.09, 13.50 | 1 | |
| Organic | Methanol | 30.58 | 29.34, 31.82 | 20 |
| Ethanol | 12.49 | 0.54, 30.38 | 3 | |
| Acetone | 25.12 | 22.35, 27.89 | 3 | |
| Acetonitrile | 42.00 | 30.69, 53.30 | 1 | |
| Chloroform–methanol | 26.25 | 26.01, 26.48 | 1 | |
| Ethyl acetate | 18.00 | 17.82, 18.17 | 1 | |
| DMSO | 6.97 | 3.73, 10.20 | 1 |
CI 95%: 95% confidence interval; GAE: gallic acid equivalent; Hydroalcoholic: a solvent mixture of water and alcohol.