Isolation, Purification and Characterization of Proteins in “Señorita” Banana (Musa acuminata (AAA) ‘Señorita’) Pulp with Bioactive Peptides Exhibiting Antihypertensive and Antioxidant Activities

John Matthew Ferreras,Lawrence Yves Uy,Amelia Hizon-Fradejas,Mia Claire Marie Clemencia,Mary Ann Torio

doi:10.3390/app11052190

John Matthew Ferreras, Lawrence Yves Uy + Show 3 more

Open Access

https://doi.org/10.3390/app11052190

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Abstract

Banana is one of the most important crops, providing multiple benefits. Although it has been widely studied for its health benefits, little information can be found about its proteins. This study determined the antihypertensive and antioxidant activities of the crude, purified, and hydrolyzed protein extracts from ‘Señorita’ banana pulp. Crude proteins were extracted using Tris-HCl buffer and purified through ammonium sulfate precipitation, dialysis, and gel filtration chromatography. The protein content of the crude, partially purified, and purified extracts were found to be 167.32, 120.45, and 28.51 μg·mL−1, respectively, with major protein having an approximate molecular weight of 15 kDa. These extracts were then subjected to enzymatic hydrolysis for release of bioactive peptides prior to ACE inhibitory and antioxidant activities determination. Among these samples, the undigested crude extract had the highest ACE inhibitory activity (85.20%). There was also an observable increase in ACE inhibition of the digested samples with increased digestion time. Meanwhile, the 3-h and 4-h crude digests had the highest DPPH radical scavenging activity with 30.82% and 34.74%, respectively. These were not significantly different from the activity of the standard, ascorbic acid. A general decrease in DPPH radical scavenging activity of the samples was observed with increased digestion time. These observations were coherent with the in silico analysis of the putative major protein, lectin, which showed that its enzymatic hydrolysis releases ACE inhibitor and antioxidant peptides.

Highlights

Banana is an important food crop worldwide, together with rice, wheat, and corn [1].It contains high amounts of vitamin B6, carbohydrates and potassium along with moderate amounts of vitamin C, manganese, and dietary fiber [2]
Given that there are only few studies which can be cited on banana proteomics and bioactive peptides, this study aims to provide preliminary data on ‘Señorita’ banana protein extraction, purification, and characterization methods, which may serve as a foundation for further banana protein studies
The low concentration of the crude extract (167.32 μg/mL buffer) was associated to the characteristic low protein content of the sample. These extracts and the peptides released during the enzymatic hydrolysis were tested for Angiotensin Converting Enzyme (ACE) inhibitory and antioxidant activities

Summary

Introduction

Banana is an important food crop worldwide, together with rice, wheat, and corn [1].It contains high amounts of vitamin B6 , carbohydrates and potassium along with moderate amounts of vitamin C, manganese, and dietary fiber [2]. Given the high consumption of the fruit worldwide, various studies associated to banana consumption have been initiated to prove its health benefits, such as its potent antioxidant, anti-diabetic, hypocholesterolemic and antihypertensive activities. Most of these are found to be associated in its phenolic compounds, carotenoids, flavonoids, biogenic amines, and phytosterols while only few being protein related [3]. 1% of the fruit pulp) and the presence of interfering compounds in higher amounts (e.g., 20% carbohydrates) makes it a difficult subject for protein studies, thereby, limiting the nature and number of available studies that can be cited up to date [5]. Most of these studies focus on optimization and comparison of different protein extraction procedures rather than the identification of isolated proteins

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