Based upon recent studies on quark condensates, we investigate strange quark matter at zero temperature and find that the mass parametrization popularly used for u/d quarks with the mass-density-dependent model is just a first-order approximation to a more general formula, whereas the corresponding formula for s quarks has to be modified, which leads to the result that the strangeness fraction in strange quark matter can exceed u/d fraction. This strangeness excess may have a negative influence on the search for strangelets in ultrarelativistic heavy ion collisions. {copyright} {ital 1997} {ital The American Physical Society}