A comparison of physical properties, oxalate-oxalic acid soluble substances, protein content, and in vitro protein digestibility of the blue-green alga Nostoc commune Vauch. from the Philippines and Japan.

The physical properties, amount of oxalate-oxalic acid soluble substances (OOSS), protein and in vitro protein digestibility of Nostoc commune from the Philippines and Japan were determined. The samples were the spherical type from the Philippines (PS), the dry field discoid type from the Philippines (PD), and the dry field discoid type from Japan (JD). The discoid types, PD and JD, regardless of origin showed higher settling volume in water (SV) and bulk density than PS. The OOSS values obtained for all samples were directly related to SV and bulk density. The WHC level was highest in PS. This desirable characteristic makes PS a technologically potential sample for large-scale food production applications in the future. Protein and in vitro protein digestibility varied significantly among all samples. In general, the algal samples examined possess desirable physical properties which are expected to be related to physiological functions.