Table 1.
The influence of stir-frying and boiling household cooking methods on bioactive metabolites and antioxidant activity after in vitro gastrointestinal digestion of African pumpkin leaves (Momordica balsamina L.) compared to whole raw leaves.
| Raw Whole Leaves | Stir-Fried Leaves | Boiled Leaves | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Bioactive Metabolites (mg 100 g −1) | RU | RG | RI | RD | SFU | SFG | SFI | SFD | BU | BG | BI | BD |
| Methylquinic acid | 0.72 ± 0.13 *,i | 578.24 ± 0.6 a | 554.45 ± 0.4 b | 2.34 ± 0.57 g | 0.06 ± 0.01 k | 265.43 ± 0.97 c | 223.25 ± 0.7 d | 0.74 ± 0.13 i | 0.26 ± 0.05 j | 62.56 ± 0.97 f | 74.82 ± 3.3 e | 1.20 ± 0.1 h |
| Pseudolaroside A | 44.90 ± 0.2 f | 210.70 ± 0.9 d | 797.65 ± 0.7 a | 127.15 ± 0.87 e | 123.43 ± 0.4 e | 453.06 ± 0.42 c | 592.41 ± 0.1 b | 34.79 ± 0.43 g | 28.20 ± 0.04 h | 20.38 ± 0.64 i | 23.17 ± 1.4 i | 4.59 ± 0.6 j |
| β-D-glucosyl-2-coumarate (Melilotoside) | 2.75 ± 0.4 j | 11.48 ± 0.3 g | 13.94 ± 0.8 g | 15.54 ± 0.8 e | 5.77 ± 1.03 i | 29.38 ± 0.94 b | 35.11 ± 0.34 a | 22.40 ± 0.36 c | 1.11 ± 0.20 k | 7.07 ± 2.21 h | 17.21 ± 0.4 d | 0.40 ± 0.1 l |
| 4 caffeoylquinic acid (Cryptochlorogenic acid) | 1.20 ± 0.21 k | 68.48 ± 0.23 e | 92.68 ± 0.35 d | 2.94 ± 0.20 j | 92.19 ± 0.4 d | 835.73 ± 0.26 b | 925.81 ± 0.41 a | 20.05 ± 1.40 g | 13.82 ± 0.4 h | 40.03 ± 0.83 f | 108.32 ± 0.6 c | 9.00 ± 1.35 i |
| Cis 4-coumaroylquinic acid | 6.01 ± 1.0 h | 113.05 ± 0.1 c | 105.45 ± 0.8 d | 2.89 ± 0.20 j | 18.15 ± 0.2 g | 286.20 ± 0.73 b | 338.27 ± 0.06 a | 7.11 ± 0.50 h | 2.21 ± 0.40 j | 32.60 ± 0.28 f | 53.25 ± 0.15 e | 3.34 ± 0.5 i |
| Trans-4-coumaroylquinic acid | 3.18 ± 0.5 h | 14.90 ± 04 f | 73.47 ± 0.28 c | 2.98 ± 0.21 i | 21.20 ± 0.7 d | 112.37 ± 0.09 b | 275.00 ± 0.11 a | 4.16 ± 0.74 g | 2.47 ± 0.44 i | 15.00 ± 1.41 f | 17.26 ± 0.18 e | 0.80 ± 0.1 j |
| Cis-4-feruloylquinic acid | 273.6 ± 0.8 f | 2351.59 ± 0.6 b | 2593.32 ± 0.5 a | 162.92 ± 0.37 h | 178.7 ± 0.9 g | 2044.65 ± 0.2 d | 2164.70 ± 0.72 c | 75.05 ± 0.24 i | 47.49 ± 0.48 j | 250.15 ± 0.34 f | 375.42 ± 0.63 e | 19.38 ± 0.9 k |
| Quercetin-3-rutinoside (Rutin) | 31.86 ± 0.9 g | 230.82 ± 0.31 d | 277.95 ± 0.06 c | 5.07 ± 0.22 j | 73.66 ± 0.15 e | 665.89 ± 0.08 b | 746.56 ± 0.48 a | 38.68 ± 0.70 g | 38.12 ± 0.8 g | 50.95 ± 0.93 f | 21.71 ± 0.84 i | 1.86 ± 0.2 k |
| Trans-4-feruloylquinic acid | 44.52 ± 095 f | 156.33 ± 0.31 d | 308.26 ± 08.78 b | 61.59 ± 0.30 e | 47.27 ± 0.44 f | 287.93 ± 0.63 c | 341.59 ± 0.64 a | 17.20 ± 0.20 h | 3.55 ± 0.63 k | 13.59 ± 0.75 i | 27.23 ± 0.8 g | 6.41 ± 0.9 j |
| Quercetin 3-galactoside | 4.05 ± 0.72 f | 41.35 ± 0.96 c | 84.21 ± 0.44 b | 3.10 ± 0.75 g | 37.47 ± 0.6 d | 322.22 ± 0.97 a | 337.18 ± 0.09 a | 8.18 ± 0.57 e | 2.83 ± 0.51 h | 3.48 ± 0.72 g | 8.61 ± 0.74 e | 1.57 ± 0.23 i |
| Kaempferol-O-rutinoside (Nicotiflorin) | 42.05 ± 0.51 f | 455.43 ± 0.42 d | 715.34 ± 0.55 a | 13.83 ± 0.97 g | 77.42 ± 0.82 e | 629.04 ± 0.15 b | 513.64 ± 0.76 c | 12.76 ± 0.89 h | 9.23 ± 1.65 i | 6.07 ± 1.37 j | 9.44 ± 0.54 i | 1.57 ± 0.23 k |
| Isorhamnetin 3-O-robinoside (Keioside) | 7.59 ± 1.36 g | 112.35 ± 0.01 d | 155.23 ± 0.43 c | 1.59 ± 0.38 i | 45.32 ± 0.09 e | 330.99 ± 01.00 b | 352.25 ± 87.35 a | 9.89 ± 0.77 f | 2.27 ± 0.41 h | 1.91 ± 0.87 i | 1.53 ± 0.58 i | 0.24 ± 0.04 j |
| Rhamnetin-3-O-glucoside | 1.05 ± 0.19 f | 12.61 ± 0.08 d | 14.54 ± 0.24 c | 0.75 ± 0.18 h | 10.08 ± 1.80 e | 64.42 ± 0.91 b | 74.36 ± 38.68 a | 1.27 ± 0.23 f | 0.47 ± 0.08 i | 0.86 ± 0.35 g | 0.38 ± 0.37 j | nd |
| Phenethyl rutinoside | 17.41 ± 3.11 c | 2.49 ± 0.29 g | 14.38 ± 0.07 d | 3.60 ± 0.25 f | 11.07 ± 0.98 e | 22.83 ± 0.50 b | 35.23 ± 4.75 a | 1.64± 0.29 i | 1.82 ± 0.33 h | 3.05 ± 2.07 f | 2.84 ± 0.89 g | 1.00 ± 0.15 j |
| Antioxidant activity | ||||||||||||
| FRAP mmol TEAC g −1 | 3.65 ± 0.01 h | 6.41 ± 0.01 f | 11.69 ± 0.02 c | 1.20 ± 0.02 j | 9.73 ± 0.02 d | 12.92 ± 0.01 b | 16.40 ± 3.10 a | 2.60 ± 0.05 i | 1.38 ± 0.01 j | 5.57 ± 0.07 g | 7.75 ± 0.01 e | 1.18 ± 0.06 j |
| DPPH IC50 (mg mL−1) | 0.53 ± 0.01 b | 0.30 ± 0.00 d | 0.18 ± 0.05 f | 0.68 ± 0.02 a | 0.22 ± 0.01 e | 0.16 ± 0.02 f | 0.13 ± 0.00 g | 0.54 ± 0.01 b | 0.40 ± 0.01 c | 0.32 ± 0.00 d | 0.28 ± 0.00 e | 0.64 ± 0.05 a |
| ABTS IC50 (mg mL−1) |
0.58 ± 0.01 d | 0.31 ± 0.03 f | 0.15 ± 0.01 h | 0.80 ± 0.01 a | 0.21 ± 0.02 g | 0.14 ± 0.00 h | 0.08 ± 0.06 i | 0.64 ± 0.02 c | 0.48 ± 0.02 e | 0.34 ± 0.00 f | 0.28 ± 0.01 g | 0.71 ± 0.01 b |
Values are mean ± standard deviation *, and means followed by a different letter within the row are significantly different (p < 0.05); RU—Raw whole leaf undigested; BU—undigested boiled leaf; SFU—undigested stir-fried leaf; RG—gastric digesta of raw leaf; BG—gastric digesta of boiled leaf; SFG—gastric digesta of stir-fried leaf; RI—Intestinal digesta of raw leaf; BI-Intestinal digesta of boiled leaf; SFI—Intestinal digesta of stir-fried leaf; RD—dialysable digesta of raw leaves; BD—dialysable digesta of boiled leaves; SFD—dialysable digesta of stir-fried leaves.