The Hong Kong Consumer Council’s latest report on dried edible fungi uncovers surprising nutritional winners—including a humble fungus that packs more iron than beef.
A comprehensive analysis published in the council’s Choice magazine (Issue 556) examined 28 samples of dried black fungus, white-back fungus, and snow fungus (also known as silver ear) collected from supermarkets, department stores, and specialty food shops between August and September 2022. The study measured soluble and insoluble fiber content along with three key minerals: calcium, iron, and potassium. Prices ranged from HK$12 to HK$99 per pack, or HK$7.90 to HK$130.30 per 100 grams.
Which Fungus Delivers the Most Iron?
Black fungus, also called cloud ear or wood ear, emerged as the standout source of iron and calcium. Per 100 grams, it contains an average of 16.2 milligrams of iron—far surpassing the 0.5 to 1.1 milligrams found in a standard serving (30 grams, about the size of a ping-pong ball) of cooked lean beef. A single 10-gram portion of dried black fungus provides 1.6 milligrams of iron after rehydration.
However, experts caution that iron from plant sources is less readily absorbed by the human body than iron from animal products. Pairing black fungus with vitamin C-rich foods—such as oranges, mangoes, kiwifruit, tomatoes, or broccoli—can enhance absorption. Conversely, drinking tea or coffee within two hours before or after a meal may reduce iron uptake due to tannic acid content.
The sample with the highest iron concentration was “菁雲 野生黑木耳” (Qing Yun Wild Black Fungus), registering 42.1 milligrams per 100 grams.
Calcium Content: A Dairy Alternative?
Black fungus also leads in calcium, averaging 443 milligrams per 100 grams—3.6 times more than white-back fungus and 10 times more than snow fungus. A 10-gram serving offers roughly 44 milligrams of calcium, equivalent to one-sixth to one-eighth of a cup of low-fat milk, and meets about 5.5% of the daily calcium recommendation for adults aged 18 to 49.
The top calcium performer was “恒興行 單葉雲耳” (Hang Hing Hong Single-Leaf Cloud Ear), with 662 milligrams per 100 grams. The council advises consumers to also get adequate sunlight exposure to produce vitamin D, which is essential for calcium absorption.
Fiber Showdown: Soluble vs. Insoluble
Dietary fiber guidelines from Hong Kong’s Centre for Food Safety define a “source” of soluble or insoluble fiber as at least 3 grams per 100 grams, and “high” as at least 6 grams. The Department of Health recommends that adolescents and adults consume no less than 25 grams of total dietary fiber daily, while children need their age plus 5 grams.
Snow fungus (silver ear) dominated in soluble fiber: all nine samples qualified as “high” sources, averaging 11.1 grams per 100 grams. The leader was “點點綠 有機銀耳” (DotDotGreen Organic Snow Fungus) with 18.4 grams. A single 10-gram serving of dried snow fungus delivers about 1.1 grams of soluble fiber and 4.8 grams of insoluble fiber—totaling 5.9 grams, or 24% of the daily recommended intake.
White-back fungus (also called hairy wood ear) offered the highest total dietary fiber, averaging 70.7 grams per 100 grams, compared to 58.3 grams for black fungus and 58.6 grams for snow fungus. The top sample was “香港啟泰 白背木耳” (Hong Kong Kai Tai White-Back Fungus), providing 74.7 grams per 100 grams—a 10-gram portion covers 30% of daily fiber needs.
Potassium Powerhouse
Snow fungus also leads in potassium, averaging 2,908 milligrams per 100 grams, versus 898 mg for black fungus and 450 mg for white-back fungus. The sample with the highest potassium was “珍殿 古田雪耳” (Zhen Dian Gutian Snow Fungus) at 3,270 mg.
Top-Rated Products by Consumer Council
The council awarded its highest rating (5 stars) to the following based on overall quality and value:
Black fungus
- 綠の聖 黑木耳 (HK$37.7 per 100g)
White-back fungus
- 香港啟泰 白背木耳 (HK$26.7)
- 尚品 白背木耳 (HK$15.0)
- 同心堂 一級木耳 (HK$14.7)
- 金御膳 白背黑木耳塊 (HK$11.0)
- 安記海味 靚木耳 (HK$9.3)
- 南北行 白背木耳 (HK$18.7)
- 老上環 白背木耳 (HK$7.9)
Snow fungus
- 御萬家 雪耳 (HK$27.8)
Products rated 4.5 stars included multiple black fungus brands such as 御品皇 雲耳 and 恒興行 單葉雲耳, plus white-back fungus from 光大 and 余仁生, and snow fungus from 盞記, 官燕棧, and 樓上.
What This Means for Your Diet
The findings reinforce that dried fungi are nutrient-dense, affordable additions to meals. Black fungus offers a plant-based iron and calcium boost, snow fungus excels in soluble fiber and potassium for heart and digestive health, and white-back fungus delivers maximum total fiber for regularity.
Consumers are encouraged to rehydrate dried fungi thoroughly before cooking, and to vary their choices to reap the distinct benefits of each type. As prices vary widely—from under HK$8 to over HK$130 per 100 grams—checking labels and council ratings can help shoppers get the best nutritional value for their money.