Oyster extract and method of preparing the same

The invention provides an oyster extract and a preparation method thereof. The extract contains biological zinc, taurine, amino acid and polypeptide; the content of amino acid and polypeptide is 5 to 23.4 percent, the content of biological zinc is 0.1 to 0.82 percent and the content of taurine is 0.5 to 8.4 percent. The preparation method combines enzymolysis and ultrasonic extraction and improves the preparation technology of oyster extract so as to obtain the oyster extract abundant in amino acid (polypeptide), biological zinc, taurine and other small-molecular functional active substances, which is suitable for the additive of beverage, particularly beer. The invention can not only effectively increase the extraction rate of the oyster extract, shorten the extraction time and save the cost, but also greatly improve the product quality and output.