Starch Concentrations in Log-Grown Shiitake Mushrooms (Lentinula edodes (Berk.) Pegler)

Shiitake (Lentinula edodes (Berk.) Pegler) mushrooms have a reputation as a healthy food, in part from the abundance of different polysaccharides that may have functional food activities. However, the total polysaccharide content of mushrooms may not represent the functional food activity if they contain significant concentrations of starch. There are few reports characterizing the starch content of shiitakes. This report summarizes several studies that examined the effects of shiitake strains, mushroom cap development, inoculated tree log species, and length of saprophytic association on the starch concentrations. Starch concentrations in shiitake mushrooms varied between 20 and 100 mg g tissue (dry weight basis). Results indicate that the starch concentrations in shiitake mushrooms are influenced by the spawn source, the characteristics of the environment and the interaction between fungal phenotypes and environment. General trends include: 1) mushrooms harvested at more immature stages of development (during bud break or before veil break) tended to have lower starch concentrations; and 2) the initial harvests of mushrooms from an inoculated log tended to have higher starch concentrations.