📊 Full nutrition facts — per 100g
| Nutrient | Amount | % Daily value | Level |
|---|---|---|---|
| Calories | 22 kcal | 1% | |
| Protein | 3.1g | 6% | |
| Vitamin D | varies by sun exp. | — | |
| Selenium | 9.3µg | 17% | |
| Riboflavin (B2) | 0.35mg | 27% | |
| Niacin (B3) | 3.8mg | 24% | |
| Copper | 0.3mg | 33% | |
| Beta-glucan | 1-3% | — | |
| Carbohydrates | 3.3g | 1% | |
| Potassium | 318mg | 7% |
Based on Australian NRV. Source: FSANZ Australian Food Composition Database.
📈 Glycaemic index (GI)
💊 Key vitamins & minerals
✅ Health benefits
Mushrooms exposed to UV light (sunlight or UV lamp) produce vitamin D2 — making them the only significant plant-based food source of this critical nutrient. Gills-up in sunlight for 15 min can produce up to 100% of daily vitamin D.
Mushroom beta-glucans stimulate natural killer cells, macrophages and dendritic cells — key components of innate immunity. Regular consumption is associated with reduced frequency and severity of colds.
Mushrooms are the richest dietary source of ergothioneine — an amino acid antioxidant that accumulates in brain tissue and is associated with reduced risk of neurodegenerative disease.
At 3.1g protein per 100g with minimal calories (22 kcal), mushrooms provide an unusually high protein-to-calorie ratio for a vegetable — valuable for plant-based diets.
⚠️ Who should limit or avoid this food
Never eat wild mushrooms unless 100% certain of identification by an expert. Australia has deadly species including the Death Cap (Amanita phalloides) which looks similar to edible species. Fatal poisoning occurs annually.
Mushroom allergy, while uncommon, can cause reactions ranging from contact dermatitis to anaphylaxis. People with mould allergies may be more likely to react.
Some mushrooms contain moderate vitamin K. Maintain consistent intake if on warfarin.
Raw mushrooms contain chitin — a tough structural compound the human gut struggles to break down. Cooking mushrooms dramatically improves digestibility and nutrient availability.
🔬 Possible side effects or risks
Chitin in raw mushrooms is indigestible and can cause bloating and gas. Cooking breaks down chitin and improves digestibility by 300% or more.
Mushrooms contain tyramine, which can trigger headaches or migraines in people with tyramine sensitivity.
At culinary amounts, mushrooms are safe. At high therapeutic doses of mushroom extracts or supplements, interactions with immunosuppressants are possible.
🛒 How to select fresh mushroom
Fresh button and portobello mushrooms should be firm, plump and uniformly coloured — creamy white to light brown. Avoid slimy, dark, shrivelled or wet mushrooms.
Gills should be intact and dry. Wet or dark-stained gills indicate age. The stem end should look freshly cut, not dried out.
Fresh mushrooms have a clean, earthy, slightly woodsy smell. Any sour, ammonia-like or 'fishy' smell indicates spoilage — discard immediately.
🧊 Storage tips & shelf life
Never store mushrooms in plastic — they need to breathe. Paper bag at room temperature if eating very soon.
Paper absorbs excess moisture that causes mushrooms to slime. Never wash until using.
Cook briefly in butter or oil first — raw frozen mushrooms become watery and unpleasant. Cooked mushrooms freeze and reheat very well.
📖 About mushroom — complete guide
Mushrooms occupy a unique position in food science — they are the only significant plant-based food that can produce vitamin D, the only food rich in ergothioneine (a brain-protective amino acid antioxidant), and contain beta-glucans that have been shown in clinical trials to stimulate specific components of the immune system. At just 22 calories per 100g with 3.1g of protein, they also offer an exceptional protein-to-calorie ratio for a vegetable.
The vitamin D-producing capacity of mushrooms deserves special attention for Australians, where vitamin D deficiency affects an estimated 31% of the population despite abundant sunshine. Simply placing mushrooms gills-side-up in direct sunlight for 15–30 minutes before cooking can elevate their vitamin D content from negligible to meeting a significant portion of daily requirements. This effect is not destroyed by cooking and is even retained in mushrooms that are subsequently dried — making sun-exposed dried mushrooms one of the richest plant-based vitamin D sources available.