TABLE 1.
Enzyme activities of SOD, CAT, APX, and H2O2 content in Tunisia husks and arils during cold storage at 4 ± 0.5°C.
| Parameters | Arginine treatment (mM) | Storage days |
||||
| 0 | 20 | 40 | 60 | 80 | ||
| Aril SOD (mkat⋅kg–1) | 0 | 0.72 ± 0.03b | 0.69 ± 0.06bc | 0.55 ± 0.03d | 0.45 ± 0.04e | 0.42 ± 0.05e |
| 0.5 | 0.74 ± 0.07b | 0.75 ± 0.04b | 0.56 ± 0.05cd | 0.51 ± 0.05d | 0.44 ± 0.05e | |
| 1.0 | 0.79 ± 0.04ab | 0.88 ± 0.05a | 0.66 ± 0.06c | 0.57 ± 0.05cd | 0.55 ± 0.05d | |
| 1.5 | 0.83 ± 0.07ab | 0.88 ± 0.04a | 0.68 ± 0.03c | 0.61 ± 0.06c | 0.59 ± 0.06cd | |
| 2.0 | 0.77 ± 0.08ab | 0.81 ± 0.07ab | 0.64 ± 0.02c | 0.59 ± 0.04cd | 0.50 ± 0.04de | |
| Husk SOD (mkat⋅kg–1) | 0 | 1.77 ± 0.10bc | 1.84 ± 0.11b | 1.79 ± 0.10bc | 1.70 ± 0.07c | 1.53 ± 0.06d |
| 0.5 | 1.79 ± 0.10bc | 1.94 ± 0.10ab | 1.80 ± 0.06b | 1.72 ± 0.06c | 1.58 ± 0.05d | |
| 1.0 | 1.90 ± 0.07b | 2.08 ± 0.08a | 1.93 ± 0.10ab | 1.87 ± 0.09b | 1.79 ± 0.06c | |
| 1.5 | 1.86 ± 0.06b | 2.04 ± 0.10a | 1.84 ± 0.11b | 1.73 ± 0.05c | 1.66 ± 0.07c | |
| 2.0 | 1.83 ± 0.07b | 2.01 ± 0.08a | 1.83 ± 0.08b | 1.66 ± 0.05c | 1.59 ± 0.05d | |
| Aril CAT (g⋅(kg⋅min)–1) | 0 | 22.80 ± 0.96a | 21.72 ± 0.78b | 20.88 ± 0.65bc | 20.16 ± 0.78c | 17.16 ± 0.50d |
| 0.5 | 22.80 ± 0.92a | 21.96 ± 0.50b | 19.80 ± 0.66d | 19.44 ± 0.55c | 17.40 ± 0.50d | |
| 1.0 | 23.88 ± 1.04a | 23.94 ± 0.42a | 21.96 ± 0.55b | 21.48 ± 0.60b | 19.92 ± 0.44c | |
| 1.5 | 23.52 ± 0.60a | 21.72 ± 0.71b | 21.00 ± 0.70bc | 20.88 ± 0.75bc | 19.56 ± 0.72c | |
| 2.0 | 23.76 ± 0.84a | 23.28 ± 0.64a | 20.64 ± 0.56bc | 19.92 ± 0.81c | 17.40 ± 0.55d | |
| Husk CAT (g⋅(kg⋅min)–1) | 0 | 19.92 ± 0.80a | 16.20 ± 0.70d | 15.84 ± 0.26d | 15.36 ± 0.50de | 14.40 ± 0.40e |
| 0.5 | 19.15 ± 0.56a | 16.80 ± 0.44d | 14.52 ± 0.81e | 13.56 ± 0.38f | 13.08 ± 0.32f | |
| 1.0 | 20.64 ± 0.68a | 20.72 ± 0.61a | 17.28 ± 0.66cd | 17.16 ± 0.84cd | 16.68 ± 0.72d | |
| 1.5 | 20.88 ± 0.50a | 20.28 ± 0.75a | 18.96 ± 0.45b | 17.40 ± 1.00cd | 16.32 ± 0.46d | |
| 2.0 | 19.20 ± 1.02a | 16.08 ± 0.70d | 16.08 ± 0.92d | 15.60 ± 0.58d | 14.88 ± 0.35e | |
| Aril APX (mkat⋅kg–1) | 0 | 31.12 ± 1.04a | 29.20 ± 0.99ab | 27.68 ± 1.00bc | 25.48 ± 0.84d | 25.01 ± 0.68d |
| 0.5 | 31.32 ± 0.92a | 28.93 ± 0.70b | 27.80 ± 1.03bc | 25.98 ± 0.60d | 25.34 ± 0.71d | |
| 1.0 | 31.39 ± 1.09a | 31.81 ± 1.05a | 29.27 ± 1.07ab | 27.47 ± 0.93c | 27.25 ± 0.75c | |
| 1.5 | 31.68 ± 1.00a | 29.87 ± 0.81ab | 28.33 ± 1.09bc | 26.58 ± 0.50cd | 26.54 ± 0.71cd | |
| 2.0 | 29.03 ± 0.90ab | 28.03 ± 0.87bc | 25.01 ± 1.02d | 23.34 ± 0.78e | 23.02 ± 0.65e | |
| Husk APX (mkat⋅kg–1) | 0 | 10.28 ± 0.52ab | 9.24 ± 0.33b | 5.47 ± 0.22d | 3.33 ± 0.22f | 2.26 ± 0.25g |
| 0.5 | 10.43 ± 0.45ab | 7.86 ± 0.38c | 5.61 ± 0.27d | 4.44 ± 0.29e | 3.09 ± 0.32f | |
| 1.0 | 11.36 ± 0.36a | 11.55 ± 0.39a | 9.11 ± 0.30b | 5.78 ± 0.20d | 4.07 ± 0.19e | |
| 1.5 | 10.76 ± 0.40a | 7.21 ± 0.21c | 6.94 ± 0.25c | 6.43 ± 0.34cd | 3.27 ± 0.37f | |
| 2.0 | 10.83 ± 0.37a | 8.67 ± 0.15b | 6.67 ± 0.27c | 3.86 ± 0.15ef | 2.57 ± 0.30g | |
| Aril H2O2 (mmol⋅kg–1) | 0 | 99.89 ± 2.39g | 114.44 ± 2.98f | 127.41 ± 2.75de | 138.30 ± 3.59cd | 175.67 ± 5.13a |
| 0.5 | 92.14 ± 2.15g | 99.37 ± 1.96g | 113.07 ± 2.39f | 126.96 ± 4.89de | 151.56 ± 3.98b | |
| 1.0 | 95.46 ± 4.19g | 103.29 ± 4.48fg | 106.16 ± 4.20f | 115.41 ± 2.80ef | 120.69 ± 4.59e | |
| 1.5 | 93.11 ± 4.06g | 106.31 ± 1.20fg | 110.72 ± 4.78f | 125.98 ± 1.96e | 132.04 ± 4.67d | |
| 2.0 | 92.00 ± 4.11g | 105.05 ± 3.54fg | 108.37 ± 2.61f | 119.33 ± 4.87e | 143.00 ± 4.00c | |
| Husk H2O2 (mmol⋅kg–1) | 0 | 109.96 ± 2.76e | 120.55 ± 5.30d | 132.85 ± 3.12cd | 160.29 ± 1.37b | 199.92 ± 6.82a |
| 0.5 | 107.05 ± 4.54e | 115.90 ± 3.52de | 128.94 ± 5.08d | 147.58 ± 2.35c | 193.57 ± 6.39a | |
| 1.0 | 101.46 ± 3.13e | 114.63 ± 3.50de | 120.85 ± 4.78d | 123.26 ± 0.98d | 137.37 ± 4.56c | |
| 1.5 | 102.74 ± 5.24e | 115.87 ± 5.00de | 124.42 ± 5.10d | 129.90 ± 5.30d | 143.19 ± 3.90c | |
| 2.0 | 106.83 ± 3.41e | 108.24 ± 4.50e | 133.29 ± 5.04cd | 160.19 ± 5.00b | 189.95 ± 6.06a | |
Values are presented as the mean ± standard error (n = 3). Different letters indicate significant differences among concentration treatments and sampling dates during cold storage (P < 0.05). SOD, superoxide dismutase; APX, ascorbate peroxidase; CAT, catalase; H2O2, hydrogen peroxide.