Table 1.
Chemical composition of brewers spent grain, and stale sourdough bread before and after 6 days solid state fermentation by N. intermedia (based on dry weight). The final composition of the fermented fungus product is also compared with a typical composition of hamburger, commercial mycoprotein product (Quorn®, UK) and soybean burger.
| Component | Brewers spent grain [%] | Stale sourdough bread [%] | Fungal product 100% stale sourdough bread | Hamburger minced meat) | Quorn® product | Soybean burger | |
|---|---|---|---|---|---|---|---|
| TAA* | 17.2 ± 0.1 | 16.5 ± 3.4 | 21.1 ± 0.5 | ||||
| Total nitrogen | 2.7 ± 0.1 | 2.0 ± 0.1 | 6.0 ± 0.2 | 9.1 | 8.1 | 3.04 | |
| Nitrogen to protein conversion factor | 5.5 | 5.3 | 5.64 | ||||
| Lipids | 7.7 ± 0.3 | 2.4 ± 0.2 | 10.5 ± 1.3 | 40.4 | 7.8 | 23.7 | |
| Total carbohydratesa) | 0 | 18.5 | 40.9 | ||||
| Xylans | 15.1 ± 0.7 | 1.7 ± 0.1 | 1.2 ± 0.1 | ||||
| Mannans | 0.3 ± 0.1 | 0.4 ± 0.1 | 3.7 ± 0.1 | ||||
| Galactans | 1.0 ± 0.2 | 0.5 ± 0.1 | 1.8 ± 0.1 | ||||
| Arabinans | 6.6 ± 0.3 | 0.9 ± 0.1 | 0.8 ± 0.1 | ||||
| Glucans | 27.2 ± 1.8 | 80.4 ± 0.1 | 30.7 ± 2.5 | ||||
| Of which starch | 8.7 ± 0.3 | 65.1 ± 0.2 | 8.5 ± 0.1 | - | - | - | |
| Lignin | 45.2 ± 0.1 | 3.0 ± 0.7 | 9.6 ± 0.7 | - | - | - | |
| Total dietary fiber | 58.1 ± 2.1 | 3.8 ± 1.2 | 22.0 ± 1.0 | 0 | 17.8 | 8.9 | |
| Total solids | 98.5 ± 0.1 | 92.6 ± 0.1 | 92.5 ± 0.2 | - | |||
| Ash | 3.3 ± 0.1 | 3.2 ± 0.1 | 7.3 ± 0.1 | 2.9 | 5.2 | 7.5 | |
| pH | 5.7 ± 0.2 | 4.7 ± 0.2 | 5.1 ± 0.3 | - | - | - | |
| Minerals [µg/g dry weight sample] |
Cu | 7.22 ± 0.48 | 4.64 ± 2.43 | 8.89 ± 0.45 | - | - | - |
| Zn | 46.04 ± 0.35 | 11.95 ± 0.44 | 34.12 ± 1.56 | 120.00 | 296 | 20.72 | |
| Fe | 30.94 ± 0.03 | 28.36 ± 0.63 | 52.17 ± 2.79 | 43.85 | 18.50 | 41.74 | |
| Vitamins [µg/g dry weight sample] |
D2 | 0.02 ± 0.00 | 0.02 ± 0.00 | 0.89 ± 0.11 | 0.01 | 0 | 0.01 |
| Eb | 2.82 | 0.32 | 27.84 | 15.64 | 0 | 56.18 | |
| C | 0.00 ± 0.00 | 0.00 ± 0.00 | 0.86 ± 0.45 | 12.86 | |||
aSum of TAA was analyzed on a molar basis minus one water molecule (18 g H2O/mol amino acid) that was integrated during the disruption of the peptide bonds [5] in the method used, before converting moles AA into g AA.
bSum of α-, ɣ- and δ-tocopherol.