Soybean (Glycine max) Protein Hydrolysates as Sources of Peptide Bitter-Tasting Indicators: An Analysis Based on Hybrid and Fragmentomic Approaches

Anna Iwaniak,Monika Hrynkiewicz,Justyna Bucholska,Małgorzata Darewicz,Piotr Minkiewicz

doi:10.3390/app10072514

Anna Iwaniak, Monika Hrynkiewicz + Show 3 more

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https://doi.org/10.3390/app10072514

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Journal: Applied Sciences	Publication Date: Apr 6, 2020
Citations: 15	License type: CC BY 4.0

Affiliation: University of Warmia and Mazury in Olsztyn

Abstract

The aim of this study was to analyze soybean proteins as sources of peptides likely to be bitter using fragmentomic and hybrid approaches involving in silico and in vitro studies. The bitterness of peptides (called parent peptides) was theoretically estimated based on the presence of bitter-tasting motifs, particularly those defined as bitter-tasting indicators. They were selected based on previously published multilinear stepwise regression results. Bioinformatic-assisted analyses covered the hydrolysis of five major soybean-originating protein sequences using bromelain, ficin, papain, and proteinase K. Verification of the results in experimental conditions included soy protein concentrate (SPC) hydrolysis, RP-HPLC (for monitoring the proteolysis), and identification of peptides using RP-HPLC-MS/MS. Discrepancies between in silico and in vitro results were observed when identifying parent peptide SPC hydrolysate samples. However, both analyses revealed that conglycinins were the most abundant sources of parent peptides likely to taste bitter. The compatibility percentage of the in silico and in vitro results was 3%. Nine parent peptides with the following sequences were identified in SPC hydrolysates: LSVISPK, DVLVIPLG, LIVILNG, NPFLFG, ISSTIV, PQMIIV, PFPSIL, DDFFL, and FFEITPEK (indicators are in bold). The fragmentomic idea of research might provide a supportive method for predicting the bitterness of hydrolysates. However, this statement needs to be confirmed experimentally.

Highlights

Soybean has been known as a food for thousands of years [1] and recently has become increasingly popular among consumers for ecological, ethical, and health-beneficial concerns [2]
Motifs that were theoretically released from a protein, excluding single amino acids, were copied, and each of them was searched for the presence of bitter-tasting peptides, according to the following protocol: BIOPEP-UWM sensory peptides and amino acids → Analysis → Profiles of proteins potential sensory activity → For your sequence
Results concerning the production of peptides likely to be bitter derived from soybean proteins showed the discrepancies between in silico and in vitro results

Summary

Introduction

Soybean has been known as a food for thousands of years [1] and recently has become increasingly popular among consumers for ecological, ethical, and health-beneficial concerns [2]. Its health-beneficial properties are due to the presence of biologically active components like isoflavones, saponins, protease inhibitors, and peptides. Their activity is related to their preventive potential against cardiovascular disease, diabetes, menopausal symptoms, osteoporosis, prostate, and breast cancers. Peptides derived from soybean proteins are responsible for a variety of activities that regulate body functions, e.g., reduction of blood pressure, cholesterol, and carbohydrate levels, as well as exhibit anti-inflammatory, antioxidative, and anticancer effects. The first three “reducing” functions of peptides are related to the inhibition of the following enzymes: ACE (angiotensin converting enzyme, EC 3.4.15.1), Appl.

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