title: Preparation of bioactive peptides with high angiotensin converting enzyme inhibitory activity from winged bean [Psophocarpus tetragonolobus (L.) DC.] seed.
abstract: Winged bean [Psophocarpus tetragonolobus (L.) DC.] seed is a potential underexploited source of vegetable protein due to its high protein content. In the present work, undefatted and defatted winged bean seed hydrolysates, designated as UWBSH and DWBSH, respectively were produced separately by four proteolytic enzymes namely Flavourzyme, Alcalase, Bromelain, and Papain using pH-stat method in a batch reactor. Enzymatic hydrolysis was carried out over a period of 0.5 to 5 h. UWBSH and DWBSH produced were tested for their ACE inhibitory activity in relation to the hydrolysis time and degree of hydrolysis (DH). Maximum ACE inhibitory activity, both for UWBSH and DWBSH, were observed during 3 to 5 h of hydrolysis. Both, UWBSH (DH 91.84 %), and DWSBH (DH 18.72 %), produced by Papain at 5 h hydrolysis, exhibited exceptionally high ACE inhibitory activity with IC50 value 0.064 and 0.249 mg mL(-1), respectively. Besides, papain-produced UWBSH and DWBSH were further fractionated into three fractions based on molecular weight (UWBSH-I, <10 kDa; UWBSH-II, <5 kDa; UWBSH-III, <2 kDa) and (DWBSH-I, <10 kDa; DWBSH-II, <5 kDa; DWBSH-III, <2 kDa). UWBSH-III revealed the highest ACE inhibitory activity (IC50 0.003 mg mL(-1)) compared with DWBSH-III (IC50 0.130 mg mL(-1)). The results of the present investigation revealed that winged bean seed hydrolysates can be explored as a potential source of ACE inhibitory peptides suggesting their uses for physiological benefits as well as for other functional food applications.
authors.affiliation: Department of Food Science, Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia.
authors.forename: Wan Abd Al-Qadr Imad
authors.initials: WA
authors.lastname: Wan Mohtar
authors.affiliation: Department of Food Science, Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia.
authors.forename: Azizah Abdul
authors.initials: AA
authors.lastname: Hamid
authors.affiliation: Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia.
authors.forename: Suraini
authors.initials: S
authors.lastname: Abd-Aziz
authors.affiliation: Department of Food Science, Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia.
authors.forename: Sharifah Kharidah Syed
authors.initials: SK
authors.lastname: Muhamad
authors.affiliation: Department of Food Science, Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Malaysia.
authors.forename: Nazamid
authors.initials: N
authors.lastname: Saari
keywords: ACE inhibitory activity; Degree of hydrolysis; IC50 value; Proximate analysis; Undefatted and defatted winged bean seed; pH-stat titration