Copper and zinc bioaccumulation and bioavailability of Ganoderma lucidum.

Ganoderma lucidum is a widely recognized medicinal mushroom. The bioaccumulation and potential bioavailability of copper (Cu) and zinc (Zn), which are essentials for human health, were analyzed in G. lucidum mycelium and fruit bodies grown in the presence of these metals to test their potential utility as a food dietary supplement. Mycelia grown in culture medium with non-mycotoxic doses of Cu or Zn (25 and 50 mg/kg) were selected for evaluation of the bioavailability of these metals in the gastrointestinal tract by using an in vitro simulated digestion system. One gram of dried mycelium grown in the presence of 50 mg/kg Cu or Zn showed a bioavailability of 19% for Cu and 2% for Zn of the recommended daily intake (RDI). When production of fruit bodies was evaluated, the highest biological efficiency (23%) was reached when the substrate was enriched with 100 mg/kg Cu. Cu and Zn contents obtained either before or after digestion of fruit bodies from all metal-enriched treatments were substantially lower than those from metal-enriched mycelia. The metal bioavailability was also low: 1.5% of the Cu RDI and almost negligible for Zn. The results are discussed in relation to the RDI values exhibited by two commercial supplements. The potential incorporation of these mineral-enriched mycelia/fruit bodies in capsules, infusions, and dietary supplements is evaluated.

Bioaccumulation and bioavailability of copper and zinc on mineral-enriched mycelium of Grifola frondosa.

Grifola frondosa is an edible and medicinal mushroom. The bioaccumulation and potential biovailability of Cu and Zn were studied to obtain mycelium with potential properties as a food dietary supplement. Mycelia grown in the presence of nonmycotoxic concentrations of 100 and 200 ppm of Cu or 25 and 50 ppm of Zn accumulated 200-322 ppm and 267-510 ppm of Cu or Zn, respectively. When these enriched metal mycelia were subjected in vitro to a simulated gastrointestinal digestion, the solubility in these digestive fluids was 642-669 ppm and 102-530 ppm, which represent 32-33% and 0.7-3.5% of the recommended daily intake (RDI) for Cu and Zn, respectively, in 1 g of mycelium. These results are discussed in relation to the RDI values exhibited by two commercial supplements, and arguments are given on the potential use of these mineral-enriched mycelia in capsules (in the case of Cu-enriched mycelia), in food preparations, and also as a component of cosmetic mixtures.

Copper- and zinc-enriched mycelium of Agaricus blazei Murrill: bioaccumulation and bioavailability.

Agaricus blazei is an edible mushroom with medicinal properties. To obtain organic combinations of potential utility as a food dietary supplement, the accumulation and potential bioavailability of copper (Cu) and zinc (Zn) on mycelium grown in the presence of these metals were studied. At 400 ppm, the mycelium accumulated 449 and 163 times the basal content of Cu and Zn, respectively. When mycelia cultivated with nonmycotoxic concentrations of Cu or Zn (100 and 200 ppm) were subjected to sequential chemical extraction and simulated gastrointestinal digestion, close to 90% of the metals accumulated in the available nonresidual fraction, which was similar to or better than the values found in two commercial supplements. The solubility in the simulated digestive fluids was 30-34% and 18-33%, i.e., 60-98% and 9-11% of the recommended daily intake for Cu and Zn, respectively, with only 1 g of mycelium.