Protein Quality Assessment of the Deoiled Guamuchil (Pithecellobium dulce [Roxb.]) Seed Flour

In this research, the amino acid composition, as well as the calculated protein efficiency ratio (C-PERa), calculated biological value (C-BVa), essential amino acid index (EsAAIn), nutritional index (NuIn), in vitro digestibility protein (InViDP), and digestibility corrected amino acid score (PDiCAASc) of a deoiled guamuchil seed flour (DoGSF) were determined as indicators of its protein quality. A total of 20 amino acids (AAs) were identified, where arginine, glutamic acid, proline, aspartic acid, and leucine were the dominants. The first, second, and third limiting AAs were methionine, cysteine, and tryptophan, respectively. Seven of the 11 essential amino acids (EsAAs) had a content higher than the FAO/WHO standard. Hydrophilic (HiAAs), positively charged (PoCAAs), and branched-chain (BrCAAs) AAs showed a good proportion in the DoGSF, with values of 59.15%, 27.43%, and 14.91%, respectively. The values of C-PERa, C-BVa, EsAAIn, NuIn, InViDP, and PDiCAASc were 0.56%–1.71%, 13.84%–29.78%, 46.98%, 15.59%, 72.3%, and 45.19%, respectively. These results demonstrated that DoGSF could be used as a complementary protein source or as a functional ingredient for the development of new foods.