Table 1.
Thickness, water solubility (WS), contact angle, wettability, mechanical properties, content of anthocyanins and betalains, and color parameters of the films.
| Parameters | CS | CSBR | CSRC | CSBC |
|---|---|---|---|---|
| Thickness (mm) | 0.36 ± 0.04 a | 0.47 ± 0.03 b | 0.43 ± 0.04 b | 0.42 ± 0.02 b |
| WS (%) | 29 ± 2 a | 36.6 ± 0.5 b | 30 ± 3 a | 37 ± 1 b |
|
Contact angle (°) measured at
20 s |
2.6 ± 0.7 a | 13.8 ± 0.8 b | 3.0 ± 0.6 a | 19.6 ± 0.5 c |
| Wettability (mN/m) | −0.03 ± 0.04 a | −2.1 ± 0.5 b | −0.08 ± 0.09 a | −4.2 ± 0.7 c |
| Stress at rupture (MPa) | 0.8 ± 0.1 ab | 0.62 ± 0.07 b | 1.2 ± 0.1 c | 1.0 ± 0.2 c |
| Deformation at rupture (mm/mm) | 2.7 ± 0.2 a | 1.2 ± 0.1 b | 0.8 ± 0.1 c | 0.9 ± 0.2 c |
| Betalains (mg/100 g) | - | 41.61 ± 0.08 | - | 8.9 ± 0.1 |
|
Anthocyanin
(mg C3G/100 g) |
- | - | 37.9 ± 0.3 | 24.9 ± 0.4 |
| Color | ||||
| L* | 85.85 ± 0.04 a | 32 ± 1 b | 54 ± 1 c | 46 ± 2 d |
| a* | −1.37 ± 0.01 a | 41 ± 2 b | 2.2 ± 0.6 a | 20 ± 1 c |
| b* | 5.41 ± 0.02 a | 23 ± 1 b | 2.6 ± 0.1 c | 15 ± 1 d |
| ∆E* | - | 69 ± 1 a | 31.1 ± 0.4 b | 45 ± 1 c |
Mean and standard deviations for n = 3 are reported. Anthocyanin content is expressed as equivalents of cyanidin-3-glucoside (C3G). (-) no data. Same letter in a row means non-significant differences (p < 0.05) between data reported. CSBR: starch-BR film; CSRC: starch-RC film; CSBC: starch-BR/RC film.