Saturday, June 9, 2012

Nutrition of cultivated mushrooms (protein, fat, carbs, and fiber)

Mushrooms! Many say they don't have much nutrition... Let's explore that.

Table 1 from P. C. K Cheung's 2010 paper, "The nutritional and health benefits of mushrooms."
Note that mushrooms are only about 10% dry weight. That means that 1 kg of fresh mushrooms is composed of 900 grams of water and 100 grams of "mushroom". The breakdown in the table above applies to that 100 grams, the so-called dry weight. So, for example, a kilogram of fresh, raw agaricus bisporus, the common button mushroom, has 24-35 grams of protein, 1-8 grams of fat, 51-63 grams of carbs, and 8-10 grams of fiber. Thus, we can say that mushrooms are relatively high in protein and carbohydrates, and low in fat and fiber.

(It is likely that the above table under-represents the variability of mushroom nutritional properties. Pirjo Matilla et. al., 2001, in "Contents of Vitamins, Mineral Elements, and Some Phenolic
Compounds in Cultivated Mushrooms" point out that "biologically active compounds are affected by differences in strain, substrate, cultivation and fruiting conditions, the developmental stage of the mushroom, and the age of the fresh mushroom sample.") 

To put this in perspective, I quickly compiled a chart comparing the nutritional content of 100 grams of bananas, commercially-prepared whole-wheat bread, raw maitake, and stir-fried shitake using information from nutritiondata.com. Here, 100 grams means 100 grams, including the water content. 

Bread wins, but it is only about 40% water, whereas the mushrooms are about 90% water. 

In the above plot, mushrooms struggle to hold their own against bread and bananas. However, if you normalize to calories, the playing field levels. This is because 100 grams of mushrooms is less than 50 calories, whereas 100 grams of bread is around 250 calories. 

Calorie for calorie, mushrooms have more protein and fiber than both bread and bananas. 


Seen from this perspective, mushrooms begin to look pretty damn nutritious!