In some embodiments, a composition is disclosed that includes pure silk fibroin-based protein fragments that are substantially devoid of sericin, wherein the composition has an average weight average molecular weight ranging from about 17 kDa to about 38 kDa, wherein the composition has a polydispersity of between about 1.5 and about 3.0, wherein the composition is substantially homogeneous, wherein the composition between 0 ppm to about 500 ppm of inorganic residuals, and wherein the composition includes between 0 ppm to about 500 ppm of organic residuals. In some embodiments, a composition is disclosed that includes silk fibroin-based protein fragments and is suitable for use in consumer applications. In some embodiments, a preserved composition is disclosed that includes silk fibroin-based protein fragments. In some embodiments, a method of preserving a solution using silk fibroin-based protein fragments is disclosed.