Portobello Nutrition, Portobello vs Cremini and Cooking Tips

A portobello is the big, flat, brown mushroom that cooks grill whole, stuff or slice into sandwiches. What surprises many shoppers is that it is not a separate kind of mushroom: portobello, cremini and the white button mushroom are the same species, Agaricus bisporus, picked at different stages and in different color strains. This guide explains that relationship with peer-reviewed sources, shows USDA SR Legacy nutrition values for raw and grilled portobello mushrooms, covers the UV-exposed versions that USDA lists with much more vitamin D, and answers the question: are portobello mushrooms healthy?

Peptide Labs does not sell portobello mushrooms or mushroom products; this guide is about the food. This article is general nutrition and cooking information, not medical advice.

What is a portobello mushroom?

Agaricus bisporus is one of the most widely cultivated mushrooms in the world. A 2020 review from Wageningen University calls it the prime mushroom species in Europe and North America and notes that it is sold in different colors, sizes and levels of maturity, from fully closed caps to fully opened ones, under names such as chestnut mushroom, common white, flats and Portobello. A 2023 review spells out the stages: the immature mushroom has a closed cap and comes in white (button) or brown (cremini) strains, while the mature mushroom is brown with an open cap and is sold as portobello, portabella or portobella.

That open cap is what makes a portobello look different. As Agaricus bisporus matures, the cap flattens and spreads, exposing the dark brown gills underneath. Our general mushrooms guide covers the white button stage in detail, and our shiitake guide covers a mushroom from a different species altogether.

Portobello vs cremini vs white button

A 2023 metabolomics study of fresh mushrooms from US farms confirmed the family resemblance. White button, cremini and portabella samples, all Agaricus bisporus, grouped together chemically and had similar amino acid profiles, while shiitake, oyster, maitake and lion’s mane each formed their own distinct clusters. Even so, the three stages were not identical: the researchers counted 255 compounds that differed significantly between cremini and portabella. The USDA values below show how close they are per 100 grams raw.

All three list 22 calories per 100 grams. Cremini and portobello list more selenium than white button in USDA data, and white button lists the most protein of the three, though none is a large protein source. In cooking, the choice of portobello vs cremini comes down mostly to size and texture: cremini are small and firm enough to slice into sauces, while portobello caps are large enough to grill or stuff whole.

Portobello nutrition: raw and grilled

USDA SR Legacy lists raw and grilled portabella entries. The table uses USDA’s own portions, a cup of diced raw mushroom (86 grams) and a cup of grilled slices (121 grams), plus the per-100-gram raw values. %DV uses FDA Daily Values.

A cup of grilled slices weighs more than a cup of raw dice (121 versus 86 grams), and per 100 grams the grilled USDA entry is also slightly more concentrated, which is why the grilled column is higher across the board. The nutrients that stand out are selenium, copper and niacin, covered in our guides to selenium in foods, niacin in foods and riboflavin in foods. Portobello also adds potassium with almost no sodium; see our guide to potassium in foods for comparisons.

UV-exposed portobello and vitamin D

Most mushrooms in stores list little vitamin D, and the regular USDA portobello entries are no exception. NIH’s Office of Dietary Supplements (ODS) says mushrooms provide variable amounts of vitamin D2, that some mushrooms on the market are exposed to UV light to raise their vitamin D2, and that FDA has approved UV-exposed mushroom powder as a food additive and source of vitamin D2. The ODS food table lists half a cup of diced raw portabella at 0.1 micrograms, 1% of the Daily Value. USDA SR Legacy also has UV-exposed portabella entries, shown below in USDA portions.

Two cautions apply. First, these are reference values for the samples USDA analyzed; the vitamin D in a given package depends on how much UV light the mushrooms received, so read the Nutrition Facts label, which states vitamin D when a product makes that claim. Second, research on whether UV-exposed mushrooms raise blood vitamin D levels is mixed: a 2016 meta-analysis of six randomized trials found no significant overall rise, with a rise in three European trials and none in three US trials. Our vitamin D foods guide lists other sources with USDA and ODS values.

Are portobello mushrooms healthy?

As a food, portobello fits a varied diet the way other vegetables do. USDA data show it is low in calories, carbohydrate and sodium, and supplies selenium, copper, niacin and potassium. It is not a meaningful protein source: a grilled cap is often used in place of a burger patty, but a cup of grilled slices lists 4 grams of protein in USDA data, far less than a beef patty; our ground beef guide and protein foods guide give the comparison values. NIH’s NCCIH has no fact sheet on Agaricus mushrooms or mushroom supplements, so this guide makes no supplement claims.

Allergy is uncommon but possible. Mushrooms are not among the nine major food allergens that US labels must declare, though FDA notes that more than 160 other foods have been reported to cause reactions. A 2024 case report described a teenager with mold allergies who had throat itching after lightly cooked mushrooms; skin tests were positive to fresh portobello and cremini but negative to canned mushrooms, which he then tolerated. If you suspect a reaction, see an allergist, and read our elimination diet guide before cutting foods on your own.

How to cook portobello mushrooms

• Cleaning: wipe the caps with a damp cloth; a quick rinse is fine if you pat them dry before cooking.
• Stems: the stems are tough; twist them out and chop them finely for stuffing or stock.
• Gills: scraping out the dark gills with a spoon is optional. It keeps sauces and fillings from turning gray-brown and leaves more room for stuffing.
• Grilling or roasting: brush the caps with olive oil, season with garlic, and cook gill side up until tender and juicy. A splash of balsamic vinegar is a classic finish.
• Slicing: thick slices hold up in fajitas, pasta and sandwiches, and dice cooks down into sauces.
• Storage: keep portobello in a paper bag in the refrigerator rather than sealed plastic, which traps moisture.

Shop for portobello mushrooms in stores and markets, which sell farmed mushrooms. Wild mushroom poisoning is serious, and CDC reports urge the public not to eat foraged wild mushrooms; our mushrooms guide summarizes that CDC report. This guide gives no advice about wild mushrooms. Mushroom-based drinks such as mushroom coffee usually use other species and are covered in their own guide.

Frequently Asked Questions

Questions about a label? Contact us or read our Buyer’s Guide. Food comes first; follow the label and ask a healthcare provider before starting a supplement, especially if you take medicines, are pregnant or have a food allergy. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Last reviewed October 2026.

Related guides: Shiitake: Nutrition, Dried Shiitake and Why to Cook Them Well, Mushroom Coffee: Benefits, Caffeine and Is It Healthy?, Low Calorie Foods: A USDA List and What Makes Them Filling.