U.S. Department of Agriculture, Agricultural Research Service. (2019). FoodData Central: Fungi, Cloud ears, dried (SR Legacy, FDC ID 168581). Per 100 g dried: 284 kcal, 9.25 g protein, 0.73 g fat, 73.0 g carbohydrate of which 70.1 g is dietary fibre, 5.88 mg iron, 159 mg calcium, 754 mg potassium, 83 mg magnesium, 43.4 µg selenium. Note the iron figure — it is an order of magnitude below the value carried in Chinese food composition tables. fdc.nal.usda.gov
Chinese Center for Disease Control and Prevention, National Institute for Nutrition and Health. China Food Composition Tables (6th ed.), consulted through the official food-composition query platform, entry 579: dried black wood ear (Auricularia). Per 100 g dried: 12.1 g protein, 1.5 g fat, 65.6 g carbohydrate, 97.4 mg iron, 247 mg calcium, 3.18 mg zinc, 3.70 µg selenium, 757 mg potassium, 152 mg magnesium. Compare USDA SR Legacy FDC ID 168581 for the same food: the potassium figures agree almost exactly (757 vs 754 mg) but iron differs about 17-fold (97.4 vs 5.88 mg) and selenium about 12-fold in the opposite direction (3.70 vs 43.4 µg) — a nutrient-specific divergence, not a unit error. nlc.chinanutri.cn/fq/foodinfo/579.html
Hunt, J. R. (2003). Bioavailability of iron, zinc, and other trace minerals from vegetarian diets. The American Journal of Clinical Nutrition, 78(3 Suppl), 633S-639S. Heme iron is absorbed far more efficiently than non-heme iron and is less affected by dietary inhibitors. The abstract gives NO absorption percentages and does not itself state the heme vs non-heme comparison above: it says iron and zinc absorption is lower from vegetarian than non-vegetarian diets, vegetarians have lower iron stores, adverse effects have not been shown with varied vegetarian diets in developed countries, and routine iron supplementation has no demonstrated benefit. The heme 15-35% / non-heme 2-20% figures sometimes attached to this record are not in it (abstract, PMID 12936958). 10.1093/ajcn/78.3.633S
National Institutes of Health, Office of Dietary Supplements. (2024). Iron — Fact Sheet for Health Professionals. Fact sheet (updated September 4, 2025; Wayback snapshot 21 September 2026): RDAs 8 mg/day for men and for women 51+, 18 mg women 19-50, 27 mg pregnancy; UL 45 mg/day from age 14; bioavailability about 14%-18% from mixed diets with meat, seafood and vitamin C and 5%-12% from vegetarian diets; serum ferritin below 30 mcg/L suggests iron deficiency and below 10 mcg/L IDA, but inflammation can raise ferritin; supplemental iron of 45 mg/day or more may cause nausea and constipation; people with hereditary hemochromatosis are at risk of iron overload (fact sheet). Heme vs nonheme: heme iron (lean meat and seafood are the richest sources) has higher bioavailability than nonheme iron, and other dietary components affect it less; calcium might reduce the bioavailability of both forms; heme iron is about 10%-15% of total iron intake in western populations. The sheet gives no separate heme and nonheme absorption percentages (fact sheet, Wayback 2026 snapshot). ods.od.nih.gov/factsheets/Iron-HealthProfessional
Han, D., Chen, J., Chen, W., & Wang, Y. (2023). Bongkrekic acid and Burkholderia gladioli pathovar cocovenenans: Formidable foe and ascending threat to food safety. Foods, 12(21), 3926. BKA is described as a flavorless, odorless, colorless, thermally stable, highly unsaturated tricarboxylic acid. (The paper states thermal stability without specifying a temperature or duration.) 10.3390/foods12213926
Centre for Food Safety, Government of the Hong Kong SAR. (2024). Bongkrekic acid - uncommon but fatal toxin in certain foods. Food Safety Focus, Issue 213. Advises soaking wood ear and tremella under refrigeration if prolonged soaking is necessary. www.cfs.gov.hk/english/multimedia/multimedia_pub/multimedia_pub_fsf_213_01.html