This invention relates to a manufacturing method of a fermented product of plant rhizome having a skin care activity, comprising the following steps: (a) grinding Chinese yam rhizome portion and mixing the same with water to form a Chinese yam solution (b) inoculating lactic acid bacteria into the Chinese yam solution (c) performing fermentation reaction for 24 -72 hours under the environment having the lactic acid bacteria and the Chinese yam solution mixed together and (d) taking out the supernatant liquid. Verified by experiments, this fermented product indeed has the efficacies of scavenging free radical, inhibiting melanin formation, and protecting the skin from UV damage.一種具有皮膚保健活性之植物根莖部發酵物之製造方法,是包含以下步驟:(a)將山藥根莖部研磨後與水混合而形成一山藥液;(b)將乳酸菌接種至該山藥液中;(c)使乳酸菌在與山藥液混合之環境下進行發酵反應24~72小時;以及(d)取出發酵後之上澄清液;經過實驗證實,此一發酵產物確實具備清除自由基、抑制黑色素形成以及防護皮膚不受紫外線傷害之功效。
