Effect of cooking on the chemical and nutritional value of the Pithecellobium flexicaule (Bent) seed.

The leguminous P. flexicaule grows at he Northeast of Mexico. People living at this region traditionally consume the seeds (unripe cooked or toasted m ature). Three localities samples of mature seeds were analyzed. The main re sults were: Protein (Nx6.25) 35.3%, lipids 25% and total dietary fiber (TDF ) 13.2%. After a toasted treatment during 10 minutes (80-90 degrees C), the true protein digestibility increased from 79.3-91.8%, the phytate content and protein inhibitors decreased up to 35 an 96% respectively. Tannin conce ntration increased from 12.4 to 236 mg eq. cathequine/100g, probably becaus e during the: treatment they passed from the shell to the cotyledons. Unrip e seeds gave; protein 12.7%, lipids 6.6%, TDF 3.5%. When the unripe seeds i n their sheath were boiling, the true protein digestibility was 85.8% (same value of the raw seeds), phytate content was reduced 68.4% and tannin conc entration rose from 4.9 to 226 mg. Due to these results, the seeds free of the shell and sheaths were boiling, this time the tannin and phytate concen tration were reduced 73.5 and 88.6% respectively, the true protein digestib ility was 94.5%. The sulphur containing amino acids were the limit, as in o ther leguminous, the protein digestibility corrected amino acid score was 5 0.6% (unripe seeds), similar to that of pinto beans.