Background
Methods
Plant sampling
Estimation of dry matter content
Extraction
Total phenolic content
Total flavonoid content
Identification and separation of flavonoids and phenolic acids
UHPLC analysis of 6-gingerol and 6-shogaol
Evaluation of antioxidant activity
1,1-Diphenyl-2-picrylhydrazyl (DPPH) assay
Ferric Reducing Antioxidant Potential (FRAP) assay
Polyphenol oxidase activity (PPO)
Antibacterial activity
Antibacterial assay
Evaluation of minimum inhibitory concentration (MIC)
Results and discussion
Dry matter content
Storage time (month)/temperature | Dry matter (%) | 6-gingerol(mg/g DM) | 6-shogaol(mg/g DM) | TPC(mg GA/g DM) | TFC(mg Q/g DM) | |
---|---|---|---|---|---|---|
Halia Bentong | fresh | 38.8 ± 2.48a | 1.47 ± 0.132d | 1.17 ± 0.04b | 11.27 ± 1.236a | 3.79 ± 0.176c |
4/(5 °C) | 37.0 ± 1.69a | 1.29 ± 0.127e | 0.94 ± 0.06c | 10.73 ± 1.327ab | 3.58 ± 0.144c | |
8/(5 °C) | 31.0 ± 1.24c | 0.61 ± 0.122f | 0.62 ± 0.052d | 8.21 ± 1.160c | 3.11 ± 0.129d | |
4/(15 °C) | 33.0 ± 1.19b | 0.38 ± 0.140g | 0.44 ± 0.027e | 6.45 ± 1.066d | 1.76 ± 0.143g | |
8/(15 °C) | 25.0 ± 1.20e | 0.30 ± 0.116g | 0.20 ± 0.016f | 5.02 ± 1.128 e | 1.19 ± 0.08h | |
Halia Bara | fresh | 27.2 ± 1.55d | 2.73 ± 0.137a | 1.55 ± 0.058a | 12.76 ± 1.352a | 4.28 ± 0.162a |
4/(5 °C) | 25.2 ± 1.27e | 2.70 ± 0.119a | 1.52 ± 0.062a | 11.62 ± 1.446a | 4.0 ± 0.177b | |
8/(5 °C) | 20.6 ± 1.12g | 2.21 ± 0.164b | 1.16 ± 0.043b | 8.70 ± 1.088c | 3.2 ± 0.152d | |
4/(15 °C) | 22.7 ± 1.46f | 1.79 ± 0.118c | 0.88 ± 0.033c | 8.00 ± 1.261c | 2.46 ± 0.112e | |
8/(15 °C) | 15.1 ± 1.23h | 1.26 ± 0.127e | 0.67 ± 0.022d | 6.80 ± 1.155d | 2.1 ± 0.094f |
Content of 6-gingerol and 6-shogaol
Total phenolic and total flavonoid content
Antioxidant activity
Storage time (month)/temperature | DPPH (%) | FRAP (μM of Fe (II)/g DM) | IC50 (DPPH) | |
---|---|---|---|---|
Halia Bentong | fresh | 41.7 ± 1.33b | 488.3 ± 29.56b | 39.2 ± 1.50f |
4/(5 °C) | 41.0 ± 1.49b | 462.8 ± 24.33b | 39.3 ± 1.22f | |
8/(5 °C) | 30.4 ± 1.58d | 371.2 ± 28.16e | 42.4 ± 1.29e | |
4/(15 °C) | 22.4 ± 1.04f | 266.7 ± 18.76f | 51.4 ± 1.42c | |
8/(15 °C) | 14.7 ± 0.44h | 176.1 ± 14.29g | 66.7 ± 1.19a | |
Halia Bara | fresh | 49.7 ± 1.88a | 537.4 ± 28.76a | 29.4 ± 1.59h |
4/(5 °C) | 47.6 ± 1.29a | 511.3 ± 32.16a | 29.8 ± 1.26h | |
8/(5 °C) | 33.4 ± 1.16c | 422.1 ± 24.38c | 33.4 ± 1.13g | |
4/(15 °C) | 24.7 ± 1.77e | 327.6 ± 20.19d | 46.7 ± 1.75d | |
8/(15 °C) | 16.9 ± 0.93g | 244.5 ± 18.46f | 55.2 ± 1.06b | |
Gallic acid | 76.1 ± 2.16 | 644.5 ± 30.52 | 24.6 ± 1.05 | |
Quercetin | 82.4 ± 2.44 | 729.2 ± 32.16 | 15.9 ± 1.27 |
Identification and separation of flavonoids and phenolic acids
Ginger varieties | Storage time (month)/temperature | Quercetin | Rutin | Catechin | Epicatechin | Kaempferol | Gallic acid | Ferulic acid | Cinnamic acid | Tannic acid |
---|---|---|---|---|---|---|---|---|---|---|
Halia Bentong | fresh | 0.922 ± 0.113b | 0.437 ± 0.034a | 0.422 ± 0.027c | 0.135 ± 0.016c | 0.076 ± 0.014d | 0.178 ± 0.056b | 0.122 ± 0.018b | 0.048 ± 0.016b | 0.077 ± 0.011b |
4/(5 °C) | 0.916 ± 0.124b | 0.430 ± 0.029a | 0.402 ± 0.034c | 0.133 ± 0.018c | 0.075 ± 0.016d | 0.172 ± 0.049b | 0.116 ± 0.016b | 0.04 ± 0.016b | 0.068 ± 0.009b | |
8/(5 °C) | 0.729 ± 0.105c | 0.311 ± 0.041b | 0.273 ± 0.022e | 0.100 ± 0.022d | 0.044 ± 0.014d | 0.113 ± 0.021c | 0.088 ± 0.015c | 0.02 ± 0.010c | 0.031 ± 0.008d | |
4/(15 °C) | 0.511 ± 0.096d | 0.168 ± 0.015c | 0.127 ± 0.019f | ND | ND | 0.100 ± 0.018c | 0.042 ± 0.014d | ND | ND | |
8/(15 °C) | 0.50 ± 0.088d | 0.120 ± 0.011d | 0.056 ± 0.013g | ND | ND | 0.061 ± 0.011d | ND | ND | ND | |
Halia Bara | fresh | 1.160 ± 0.126a | 0.355 ± 0.032b | 0.568 ± 0.059a | 0.166 ± 0.063a | 0.96 ± 0.124a | 0.211 ± 0.042a | 0.162 ± 0.063a | 0.091 ± 0.026a | 0.122 ± 0.019a |
4/(5 °C) | 1.100 ± 0.137a | 0.322 ± 0.027b | 0.517 ± 0.063a | 0.144 ± 0.012b | 0.86 ± 0.116a | 0.210 ± 0.033a | 0.146 ± 0.032a | 0.083 ± 0.016a | 0.120 ± 0.016a | |
8/(5 °C) | 0.762 ± 0.092c | 0.300 ± 0.042b | 0.488 ± 0.034b | 0.122 ± 0.017c | 0.80 ± 0.114a | 0.155 ± 0.024b | 0.121 ± 0.017b | 0.043 ± 0.031b | 0.110 ± 0.013a | |
4/(15 °C) | 0.426 ± 0.076e | 0.156 ± 0.018c | 0.416 ± 0.024c | 0.110 ± 0.016d | 0.619 ± 0.076b | 0.110 ± 0.019c | 0.066 ± 0.051c | ND | ND | |
8/(15 °C) | 0.281 ± 0.049f | 0.112 ± 0.021d | 0.362 ± 0.030d | 0.064 ± 0.018e | 0.522 ± 0.053c | 0.056 ± 0.014d | 0.029 ± 0.010e | ND | ND |
Polyphenol oxidase activity
Antibacterial activity
Ginger varieties | Inhibition zone (mm) | ||||||
---|---|---|---|---|---|---|---|
Storage time (month)/temperature |
S. aureus
|
B.subtilis
|
L.monocytogenes
|
E. coli
|
S. typhimurium
|
P. aeruginosa
| |
Halia Bentong | fresh | 11.5 ± 1.33b | 12.5 ± 1.35c | 14.0 ± 1.66b | 12.0 ± 1.25b | 11.0 ± 1.27a | 13.5 ± 1.28a |
4/(5 °C) | 8.5 ± 0.69b | 7.1 ± 0.68b | 9.0 ± 0.73c | 8.6 ± 0.54c | 8.3 ± 0.26b | 9.5 ± 1.01b | |
8/(5 °C) | 5.3 ± 0.373d | 4.2 ± 0.67d | 5.6 ± 0.144e | 3.5 ± 0.21e | 3.5 ± 0.19d | 5.6 ± 0.19d | |
4/(15 °C) | 3.1 ± 0.22f | 2.2 ± 0.12e | 5.5 ± 0.16e | NO | NO | NO | |
8/(15 °C) | 1.4 ± 0.13g | 1.2 ± 0.08g | 2.2 ± 0.09g | NO | NO | NO | |
Halia Bara | fresh | 14.0 ± 2.62a | 15.5 ± 2.52a | 16.0 ± 2.15a | 13.5 ± 1.55a | 12.0 ± 1.42b | 15.0 ± 1.26b |
4/(5 °C) | 9.2 ± 0.58b | 8.5 ± 0.47a | 11.5 ± 1. 88b | 6.8 ± 0.46c | 7.8 ± 0.81c | 8.0 ± 0.61c | |
8/(5 °C) | 6.4 ± 0.467c | 4.6 ± 0.33c | 6.5 ± 0.72e | 2.0 ± 0.17d | 2.4 ± 0.28d | 3.5 ± 0.27d | |
4/(15 °C) | 4.2 ± 0.329e | 3.6 ± 0.29d | 7.5 ± 0.58d | NO | NO | NO | |
8/(15 °C) | 2.2 ± 0.149g | 2.8 ± 0.18f | 3.40 ± 0.15f | NO | NO | NO |
Ginger varieties | Storage time (month)/temperature |
S. aureus
|
B.subtilis
|
L.monocytogenes
|
E. coli
|
S. typhimurium
|
P. aeruginosa
|
---|---|---|---|---|---|---|---|
Halia Bentong | fresh | 40 | 60 | 80 | 80 | 60 | 60 |
4/(5 °C) | 40 | 60 | 80 | >100 | >100 | 80 | |
8/(5 °C) | 60 | 80 | >100 | >100 | >100 | >100 | |
4/(15 °C) | >100 | >100 | >100 | NO | NO | NO | |
8/(15 °C) | >100 | >100 | >100 | NO | NO | NO | |
Halia Bara | fresh | 40 | 60 | 80 | 80 | 60 | 60 |
4/(5 °C) | 40 | 60 | 80 | 80 | 80 | 80 | |
8/(5 °C) | 60 | 80 | >100 | >100 | >100 | >100 | |
4/(15 °C) | 80 | >100 | >100 | NO | NO | NO | |
8/(15 °C) | >100 | >100 | >100 | NO | NO | NO |