title: Effects of heat and pH treatments and in vitro digestion on the biological activity of protein hydrolysates ofAmaranthus hypochondriacusL. grain.
abstract: The aim of this work was to assess the effects of temperature (T), time (t) and pH treatments and an in vitro digestion on the stability of the angiotensin I-converting-enzyme-inhibitory activity (ACEIA) and antithrombotic activity (ATA; assessed as inhibition of platelet aggregation) of selected protein hydrolysates of amaranth named Alb1H103 and GloH88 and GluH24 with dipeptidyl peptidase IV inhibitory activity (DPPIVIA). Heat treatment (40-100 °C) for 1 h showed no significant differences among ACEIA, DPPIVIA and ATA of the heated hydrolysates at pH 4 and 7. There was no statistically significant loss of any bioactivity under heat treatment for 3 h at pH 4.0. Alb1H103 and GluH24 maintained the inhibitory activity of ACE and ATA at pH 7.0 for 3 h, whereas GloH88 maintained ACEIA and ATA for 2.0 h at pH 7.0. The pH effect on hydrolysates bioactivity was assessed in the range of 2.0-12.0. This was negligible on ACEIA, ATA and DPPIVIA. The in vitro digestion was performed using pepsin, trypsin (T) and α-chymotrypsin (C). A previous treatment of hydrolysates with pepsin improved theproteolytic activities of T and C.The hydrolysates kept at 100 °C for 1 h at pH 4.0, showed a significant increase in bioactivity. Conversely, a treatment at pH 7.0 showed no significant difference (p< 0.05) in the hydrolysates bioactivities after their digestion. Thus, biological activity of hydrolysates may be preserved or enhanced, depending on their processing conditions.
authors.affiliation: Departamento de Biotecnología, Universidad Autónoma Metropolitana, Campus Iztapalapa, Av. San Rafael Atlixco No. 186, Col. Vicentina, Ap. P. 55-535, Deleg. Iztapalapa, 09340 Mexico City, Mexico.
authors.forename: J
authors.initials: J
authors.lastname: López-Sánchez
authors.affiliation: Departamento de Biotecnología, Universidad Autónoma Metropolitana, Campus Iztapalapa, Av. San Rafael Atlixco No. 186, Col. Vicentina, Ap. P. 55-535, Deleg. Iztapalapa, 09340 Mexico City, Mexico.
authors.forename: E
authors.initials: E
authors.lastname: Ponce-Alquicira
authors.affiliation: Departamento de Ingeniería y Ciencias Químicas, Universidad Iberoamericana, Prolongación Paseo de la Reforma 880, Lomas de Santa Fe, 01219 Mexico City, Mexico.
authors.forename: R
authors.initials: R
authors.lastname: Pedroza-Islas
authors.affiliation: Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, Circuito Escolar, Ciudad Universitaria, Coyoacán, 04510 Mexico City, Mexico.
authors.forename: A
authors.initials: A
authors.lastname: de la Peña-Díaz
authors.affiliation: Departamento de Biotecnología, Universidad Autónoma Metropolitana, Campus Iztapalapa, Av. San Rafael Atlixco No. 186, Col. Vicentina, Ap. P. 55-535, Deleg. Iztapalapa, 09340 Mexico City, Mexico.
authors.forename: J
authors.initials: J
authors.lastname: Soriano-Santos
keywords: ACE-inhibition; Amaranth; Antithrombotic activity; DPP IV inhibition; Hydrolysate