Precooked sorghum flour as proper vehicle of ACE-I and DPP-IV inhibitory sorghum peptides

Sorghum flour was heat treated for producing an instant dispersion ingredient. The precooked sorghum flour was added with ACE-I and DPP-IV inhibitory sorghum peptides (3.0 g peptide 100 g(-1)). The product was reconstituted in water, and peptide bioaccessibility was evaluated by equilibrium dialysis method after simulated gastrointestinal digestion. Total peptide dialysability of precooked sorghum flour added with sorghum peptides was higher than those obtained for precooked sorghum flour (315.9 +/- 14.8 vs. 45.2 +/- 5.6 mu mol, respectively) (P < 0.05). The ACE-I and DPP-IV-IC50 values of the bioaccessible peptides from the bioactive product were lower than those obtained for precooked sorghum flour ingredient (1.04 +/- 0.12 vs. 1.82 +/- 0.09 and 0.86 +/- 0.02 vs. 2.12 +/- 0.08 mg protein mL(-1), for ACE-I and DPP-IV, respectively) indicating a higher activity. Precooked sorghum flour was a good vehicle since it did not affect the bioaccessibility of ACE-I and DPP-IV inhibitory peptides provided by sorghum protein hydrolysate.

Automated summary

Heat-treated sorghum flour, when added with ACE-I and DPP-IV inhibitory sorghum peptides, showed increased bioaccessibility. Precooked sorghum flour, as a carrier, did not affect the bioaccessibility of the inhibitory peptides provided by sorghum protein hydrolysate.