| In recent years, developments of safe, effective and low-cost zinc supplementation of food have increasingly become research hot spots among areas of food science, medicine and biology. Use edible fungus as a carrier, the technology of transforming inorganic zinc which the human body can not directly absorbed into organic zinc, not only has short production cycle, and low-cost advantages, but also could improve nutritional contents of the edible fungus itself. Loetiporus sulphureus is a kind of being domesticated wild edible (medicinal)fungus, which contains eburicoic acid and other active ingredients, is capable of regulating immune function, improving health and enhancing resistance. Zinc content in fruiting body of wild Loetiporus sulphureus is very low. This study wanted to use the Loetiporus sulphureus as a carrier to transform organic zinc, which not only could enhance the edible (medicinal) value and commodity value of the edible fungus, but also could provide a new way for the development of zinc-rich health care products.The optimal concentration of exogenous zinc salts, the optimal liquid culture conditions, the impact of zinc on mycelial extracellular enzyme activity and physical and chemical basis, the impact of different types and concentrations of inorganic salts, vitamins on zinc absorption were studied in this paper. The results were as follows.①Determined zinc sulfate as the optimal zinc salts, and the highest amount of mycelial biomass and zinc obtained at 200 mg/L of zinc concentration. ②Optimized liquid culture conditions of Loetiporus sulphureus transforming organic zinc: medium volume 80mL/250mL, inoculum size 7.5%, initial pH value 6-7, culture temperature 25℃, shaking speed 120 r/m, culture time for 7 days.③Vitamin A, vitamin B6 facilitates mycelia zinc absorption significantly.≤0.1mg/L of calcium chloride of ferrous sulfate on the medium can promote zinc absorption. But when the added concentration>0.1 mg/L, the calcium chloride, ferrous sulfate both showed significant inhibitory effect on zinc absorption of mycelia.④As the zinc concentration increased, mycelia soluble sugar content showed an upward trend after the first decrease, while the polysaccharide and soluble protein contents were increased at first, then downward. The inflection point of three trends of change focused on the zinc concentration of 100 mg/L.⑤Zinc on the changes in enzymes activity had a certain impact. Suitable concentration of zinc would increase the activity of mycelial extracellular enzyme and promote mycelia on nutrient absorption. But the zinc added, did not change the change trends of enzymes activity.
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